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Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2019	Feb. 28, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	PARSONS CORPORATION
Entity Central Index Key	0000275880
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		100,669,694
Entity Public Float			$ 3.7
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	001-07782
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	95-3232481
Entity Address, Address Line One	5875 Trinity Parkway, #300
Entity Address, City or Town	Centreville
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	21120
City Area Code	703
Local Phone Number	988-8500
Document Annual Report	true
Document Transition Report	false
Title of each class	Common Stock, $1 par value
Trading Symbol(s)	PSN
Name of each exchange on which registered	NYSE
Documents Incorporated by Reference	Portions of Parsons’ 2020 Proxy Statement are incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents (including $73,794 and $51,171 Cash of consolidated joint ventures)	$ 182,688	$ 280,221
Restricted cash and investments	12,686	974
Accounts receivable, net (including $180,325 and $166,355 Accounts receivable of consolidated joint ventures, net)	671,492	623,286
Contract assets (including $21,270 and $26,458 Contract assets of consolidated joint ventures)	575,089	515,319
Prepaid expenses and other current assets (including $11,837 and $11,182 Prepaid expenses and other current assets of consolidated joint ventures)	84,454	69,007
Total current assets	1,526,409	1,488,807
Property and equipment, net (including $2,561 and $2,945 Property and equipment of consolidated joint ventures, net)	122,751	91,849
Right of use assets, operating leases	233,415
Goodwill	1,047,425	736,938
Investments in and advances to unconsolidated joint ventures	68,620	63,560
Intangible assets, net	259,858	179,519
Deferred tax assets	130,401	5,680
Other noncurrent assets	61,489	46,225
Total assets	3,450,368	2,612,578
Current liabilities
Accounts payable (including $87,914 and $85,869 Accounts payable of consolidated joint ventures)	216,613	226,345
Accrued expenses and other current liabilities (including $73,209 and $74,857 Accrued expenses and other current liabilities of consolidated joint ventures)	639,863	559,700
Contract liabilities (including $38,706 and $32,638 Contract liabilities of consolidated joint ventures)	230,681	208,576
Short-term lease liabilities, operating leases	49,994
Income taxes payable	7,231	11,540
Total current liabilities	1,144,382	1,006,161
Long-term employee incentives	56,928	41,913
Deferred gain resulting from sale-leaseback transactions		46,004
Long-term debt	249,353	429,164
Long-term lease liabilities, operating leases	203,624	0
Deferred tax liabilities	9,621	6,240
Other long-term liabilities	125,704	127,863
Total liabilities	1,789,612	1,657,345
Contingencies (Note 15)
Redeemable common stock held by Employee Stock Ownership Plan (ESOP), $1 par value; 78,172,809 and 0 shares outstanding, recorded at redemption value		1,876,309
Shareholders' equity (deficit)
Common stock, $1 par value; authorized 1,000,000,000 shares; 125,097,684 and 146,440,701 shares issued; 0 and 21,772,888; 0 and 78,896,806 shares and ESOP shares outstanding	146,441
Treasury stock, 46,918,140 and 45,771,008 shares at cost	(934,240)	(957,025)
Additional paid-in capital	2,649,975
Retained earnings (accumulated deficit)	(218,025)	12,445
Accumulated other comprehensive income	(14,261)	(22,957)
Total Parsons Corporation shareholders' equity (deficit)	1,629,890	(967,537)
Noncontrolling interests	30,866	46,461
Total shareholders' equity (deficit)	1,660,756	(921,076)
Total liabilities, redeemable common stock and shareholders' equity (deficit)	$ 3,450,368	$ 2,612,578

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Cash and cash equivalents	$ 182,688	$ 280,221
Accounts receivable, net	671,492	623,286
Contract assets	575,089	515,319
Prepaid expenses and other current assets	84,454	69,007
Property and equipment, net	122,751	91,849
Accounts payable	216,613	226,345
Accrued expenses and other current liabilities	639,863	559,700
Contract liabilities	$ 230,681	$ 208,576
Temporary equity, par value	$ 1	$ 1
Temporary equity, shares outstanding	0	78,172,809
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares, issued	146,440,701	125,097,684
Common stock, shares, outstanding	21,772,888	0
Treasury stock, shares	45,771,008	46,918,140
Consolidated Joint Ventures
Cash and cash equivalents	$ 51,171	$ 73,794
Accounts receivable, net	166,355	180,325
Contract assets	26,458	21,270
Prepaid expenses and other current assets	11,182	11,837
Property and equipment, net	2,945	2,561
Accounts payable	85,869	87,914
Accrued expenses and other current liabilities	74,857	73,209
Contract liabilities	$ 32,638	$ 38,706
Employee Stock Ownership Plan
Common stock, shares, outstanding	78,896,806	0

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Income Statement [Abstract]
Revenue	$ 3,954,812	$ 3,560,508	$ 3,017,011
Direct cost of contracts	3,123,062	2,795,005	2,400,140
Equity in earnings of unconsolidated joint ventures	41,721	36,915	40,086
Indirect, general and administrative expenses	781,408	597,410	506,255
Operating income	92,063	205,008	150,702
Interest income	1,300	2,710	2,465
Interest expense	(23,729)	(20,842)	(15,798)
Other income (expense), net	(2,392)	(1,651)	5,658
(Interest and other expense) gain associated with claim on long-term contract		74,578	(10,026)
Total other (expense) income	(24,821)	54,795	(17,701)
Income before income tax expense	67,242	259,803	133,001
Income tax (expense) benefit	69,886	(20,367)	(21,464)
Net income including noncontrolling interests	137,128	239,436	111,537
Net income attributable to noncontrolling interests	(16,594)	(17,099)	(14,211)
Net income attributable to Parsons Corporation	$ 120,534	$ 222,337	$ 97,326
Earnings per share:
Basic earnings per share	$ 1.30	$ 2.78	$ 1.16
Diluted earnings per share	$ 1.30	$ 2.78	$ 1.16

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income including noncontrolling interests	$ 137,128	$ 239,436	$ 111,537
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment, net of tax	8,418	(7,800)	4,793
Pension adjustments, net of tax	281	(56)	(95)
Comprehensive income including noncontrolling interests, net of tax	145,827	231,580	116,235
Comprehensive income attributable to noncontrolling interests, net of tax	(16,597)	(17,197)	(14,210)
Comprehensive income attributable to Parsons Corporation, net of tax	$ 129,230	$ 214,383	$ 102,025

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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+ Details

Consolidated Statements of Changes in Redeemable Common Stock and Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	IPO	Redeemable Common Stock	Common Stock	Common Stock IPO	Treasury Stock	Accumulated Deficit	Additional Paid-in Capital	Additional Paid-in Capital IPO	Accumulated Other Comprehensive (Loss) Income	Total Parsons Equity (Deficit)	Total Parsons Equity (Deficit) IPO	Noncontrolling Interest
Beginning balance at Dec. 30, 2016	$ (935,542)					$ (806,119)	$ (166,890)			$ (19,702)	$ (992,711)		$ 57,169
Beginning balance, Temporary Equity at Dec. 30, 2016			$ 1,739,431
Comprehensive income (loss)
Net (loss) income	111,537						97,326				97,326		14,211
Foreign currency translation (loss) gain	4,793									4,794	4,794		(1)
Pension adjustments	(95)									(95)	(95)
Purchase of treasury stock						(111,403)	111,403
Temporary equity, Purchase of treasury stock			(111,403)
Contributions of treasury stock to ESOP						41,150	(41,150)
Temporary equity, Contributions of treasury stock to ESOP			40,553
Contributions	7,481												7,481
Distributions	(51,366)												(51,366)
ESOP shares at redemption value	(186,724)						(186,724)				(186,724)
Temporary equity, ESOP shares at redemption value			186,724
Ending Balance at Dec. 29, 2017	(1,049,916)					(876,372)	(186,035)			(15,003)	(1,077,410)		27,494
Ending Balance, Temporary Equity at Dec. 29, 2017			1,855,305
Comprehensive income (loss)
Net (loss) income	239,436						222,337				222,337		17,099
Foreign currency translation (loss) gain	(7,800)									(7,898)	(7,898)		98
Pension adjustments	(56)									(56)	(56)
Adjustment due to adoption of ASC \| ASC 606	(4,735)						(4,735)				(4,735)
Purchase of treasury stock						(125,814)	125,814
Temporary equity, Purchase of treasury stock			(125,814)
Contributions of treasury stock to ESOP						45,161	(45,161)
Temporary equity, Contributions of treasury stock to ESOP			47,043
Contributions	20,656												20,656
Distributions	(18,886)												(18,886)
ESOP shares at redemption value	(99,775)						(99,775)				(99,775)
Temporary equity, ESOP shares at redemption value			99,775
Ending Balance at Dec. 31, 2018	(921,076)					(957,025)	12,445			(22,957)	(967,537)		46,461
Ending Balance, Temporary Equity at Dec. 31, 2018	1,876,309		1,876,309
Comprehensive income (loss)
Net (loss) income	137,128						120,534				120,534		16,594
Foreign currency translation (loss) gain	8,418									8,415	8,415		3
Pension adjustments	281									281	281
Adjustment due to adoption of ASC \| ASC 842	52,608						52,608				52,608
Purchase of treasury stock	(53)					(6,272)	6,219				(53)
Temporary equity, Purchase of treasury stock			(6,219)
Contributions of treasury stock to ESOP	53,644					29,057		$ 24,587			53,644
Contributions	10,093												10,093
Distributions	(42,285)												(42,285)
Dividend paid	(52,093)						(52,093)				(52,093)
Stock-based compensation	8,272							8,272			8,272
Issuance of equity securities, net of retirements/ IPO proceeds, net	(1,149)	$ 536,878		$ 47	$ 21,296		(197)	(999)	$ 515,582		(1,149)	$ 536,878
Conversion of S-Corp to C-Corp	(25,877)						(25,877)				(25,877)
Temporary equity, Conversion of S-Corp to C-Corp			25,877
ESOP shares at redemption value	(857,559)						(331,664)	(525,895)			(857,559)
Temporary equity, ESOP shares at redemption value			857,559
Temporary to permanent equity end of lock-up period	2,753,526		$ (2,753,526)	125,098				2,628,428			2,753,526
Ending Balance at Dec. 31, 2019	$ 1,660,756			$ 146,441		$ (934,240)	$ (218,025)	$ 2,649,975		$ (14,261)	$ 1,629,890		$ 30,866

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Cash flows from operating activities
Net income including noncontrolling interests	$ 137,128	$ 239,436	$ 111,537
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	125,700	69,869	35,198
Amortization of deferred gain	0	(7,253)	(7,283)
Amortization of debt issue costs	973	721	504
Gain associated with claim on long-term contract	0	(129,674)	0
Loss on disposal of property and equipment	1,042	780	1,184
Provision for doubtful accounts	290	5,255	12,530
Deferred taxes	(123,338)	(1,422)	5,403
Foreign currency transaction gains and losses	4,472	5,224	(5,121)
Equity in earnings of unconsolidated joint ventures	(41,721)	(36,915)	(40,086)
Return on investments in unconsolidated joint ventures	51,077	35,192	33,377
Stock-based compensation	8,272	0	0
Contributions of treasury stock	53,644	45,161	40,553
Changes in assets and liabilities, net of acquisitions and newly consolidated joint ventures
Accounts receivable	(30,206)	461,304	(2,958)
Contract assets	(49,999)	(480,090)	0
Prepaid expenses and current assets	(22,110)	(23,668)	(10,850)
Accounts payable	(17,123)	5,566	27,334
Accrued expenses and other current liabilities	78,366	30,367	26,153
Billings in excess of costs	0	(150,873)	7,900
Contract liabilities	20,146	205,047	0
Provision for contract losses	0	(13,795)	19,431
Income taxes	(5,421)	3,911	2,518
Other long-term liabilities	29,048	20,491	7,705
Net cash provided by operating activities	220,240	284,634	265,029
Cash flows from investing activities
Capital expenditures	(67,597)	(29,283)	(27,939)
Proceeds from sale of property and equipment	3,789	439	2,250
Payments for acquisitions, net of cash acquired	(494,826)	(481,163)	(25,737)
Investments in unconsolidated joint ventures	(24,579)	(4,720)	(3,502)
Return of investments in unconsolidated joint ventures	12,410	11,432	1,967
Net cash used in investing activities	(570,803)	(503,295)	(52,961)
Cash flows from financing activities
Proceeds from borrowings	597,200	260,000	0
Repayments of borrowings	(777,200)	(80,000)	0
Payments for debt costs and credit agreement	(286)	(545)	(1,949)
Contributions by noncontrolling interests	10,093	20,656	7,481
Distributions to noncontrolling interests	(42,285)	(18,886)	(51,366)
Purchase of treasury stock	(6,272)	(125,814)	(111,403)
IPO proceeds, net	536,879	0	0
Dividend paid	(52,093)	0	0
Deferred payments for acquisitions	0	0	(2,934)
Net cash (used in) provided by financing activities	266,036	55,411	(160,171)
Effect of exchange rate changes	(1,294)	(1,699)	1,235
Net (decrease) increase in cash, cash equivalents and restricted cash	(85,821)	(164,949)	53,132
Cash, cash equivalents and restricted cash
Beginning of year	281,195	446,144	393,012
End of year	195,374	281,195	446,144
Cash paid during the year for
Interest	23,254	16,805	12,905
Income taxes (net of refunds)	$ 60,477	$ 17,054	$ 14,364

Description of Operations

12 Months Ended

Dec. 31, 2019

Description Of Operations Disclosure [Abstract]

Description of Operations

1.	Description of Operations

Organization

Parsons Corporation, a Delaware corporation, and its subsidiaries (collectively, the “Company”) provide sophisticated design, engineering and technical services, and smart and agile software to the United States federal government and Critical Infrastructure customers worldwide. The Company performs work in various foreign countries through local subsidiaries, joint ventures and foreign offices maintained to carry out specific projects.

Initial Public Offering

On May 8, 2019, the Company consummated its initial public offering (“IPO”) whereby the Company sold 18,518,500 shares of common stock for $27.00 per share. The underwriters exercised their share option on May 14, 2019 to purchase an additional 2,777,775 shares at the share price of $25.515 which was the IPO share price of $27.00 less the underwriting discount of $1.485 per share. The net proceeds of the IPO and the underwriters’ share option were $536.9 million, after deducting underwriting discounts and other fees, and were used to fund an IPO dividend of $52.1 million, repay the outstanding balance of $150.0 million under our Term Loan, and repay outstanding indebtedness under our Revolving Credit Facility.

Stock Dividend

On April 15, 2019, the board of directors of the Company declared a common stock dividend in a ratio of two shares of common stock for every one share of common stock then held by the Company’s stockholder (the “Stock Dividend”). The record date of this common Stock Dividend was May 7, 2019, the day immediately prior to the consummation of the Company’s IPO on May 8, 2019, and the payment date of the Stock Dividend was May 8, 2019. Purchasers of the Company’s common stock in the Company’s public offering were not entitled to receive any portion of the Stock Dividend.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Summary of Significant Accounting Policies

2.	Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of Parsons Corporation and its subsidiaries and affiliates which it controls. Interests in joint ventures that are controlled by the Company, or for which the Company is otherwise deemed to be the primary beneficiary, are consolidated. For joint ventures in which the Company does not have a controlling interest, but exerts significant influence, the Company applies the equity method of accounting. Intercompany accounts and transactions are eliminated in consolidation.

Fiscal Year

The Company reports results of operations based on a calendar year end date of December 31 starting in 2018. Prior to 2018, the Company reported results of operations based on a 52- or 53-week periods ending the last Friday on or before December 31. For 2017, this date was December 29, 2017, and 2017 was comprised of 52 weeks.

Use of Estimates

The preparation of the consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual amounts could differ from those estimates. The Company’s most significant estimates and judgments involve revenue recognition with respect to the determination of the costs to complete contracts and transaction price; determination of self-insurance reserves; valuation of the Company’s fair value of common stock prior to the conclusion of the 180-day lock-up period on November 3, 2019; useful lives of property and equipment and intangible assets; calculation of allowance for doubtful accounts; valuation of deferred income tax assets and uncertain tax positions, among others.

ESOP

The Company maintains a non-leveraged ESOP for eligible employees, for which the Company contributes shares of its own stock to the ESOP trust each year. Shares held by the ESOP or committed to be contributed to the ESOP were presented as temporary equity at December 31, 2018 as they included a cash redemption feature that was not solely within the Company’s control. At the IPO date, shares held by the ESOP were subject to a 180-day lock-up period. At the conclusion of the 180-day lock-up period ESOP distributions are no longer made in cash. Shares held by the ESOP have been reclassified from temporary equity to permanent equity at December 31, 2019.

Throughout the year, as employee services are rendered, the Company records compensation expense based on salaries of eligible employees. At each reporting period, the shares held within the ESOP or committed to be contributed to the ESOP are adjusted to their redemption value through an offsetting charge or credit to accumulated deficit.

Treasury Stock

The Company records treasury stock purchases under the cost method whereby the entire cost of the acquired stock is recorded as treasury stock. The Company records the reissuance of treasury stock using the first-in, first-out method of accounting. Contributions of 1,790,496 shares, 1,874,988 shares and 1,345,198 shares of common stock were made to the ESOP in fiscal 2017, 2018 and 2019, respectively. In fiscal 2017, 2018 and 2019 the Company repurchased 5,843,211 shares, 5,553,891 shares and 191,331 shares of common stock from the ESOP, respectively, in connection with the redemption of ESOP participants’ interests in the ESOP for $111.4 million, $125.8 million and $6.3 million, respectively.

Earnings per Share

Basic earnings per common share (“EPS”) is calculated by dividing Net income by the weighted average number of common shares outstanding during the year. Diluted earnings per common share is calculated by dividing net income by adjusted weighted average outstanding shares, assuming conversion of all potentially dilutive securities. Upon contribution to the ESOP, the shares become outstanding and are included within the earnings per share computations.

Revenue Recognition

On December 30, 2017, the Company adopted Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers”, and the related ASU’s subsequently issued by the Financial Accounting Standards Board (the “FASB”) (“ASC 606”) using the modified retrospective method. As a result, the Company revised its accounting policy on revenue recognition and the results for reporting periods beginning after December 29, 2017 are presented under ASC 606. In accordance with ASC 606, the Company follows the five-step process in ASC 606 to recognize revenue:

Identify the contract

Identify performance obligations

Determine the transaction price

Allocate the transaction price

Recognize revenue

Contracts—Revenue is derived from long-term contracts with customers whereby the Company provides planning, design, engineering, technical, and construction and program management services. The Company has contracts with the United States federal government that contain provisions requiring compliance with the United States Federal Acquisition Regulation (“FAR”) and the United States Cost Accounting Standards (“CAS”). These regulations are generally applicable to all of the Company’s federal government contracts and are partially or fully incorporated in some local and state agency contracts. Most of the Company’s federal government contracts are subject to termination at the convenience of the client. These contracts typically provide for reimbursement of costs incurred and payment of fees earned through the date of such termination.

The Company enters into the following types of contracts with its customers:

Cost-Plus—Under cost-plus contracts, the Company is reimbursed for allowable or otherwise defined costs incurred, plus a fee. The contracts may also include incentives for various performance criteria, including quality, timeliness, safety and cost-effectiveness. In addition, costs are generally subject to review by clients and regulatory audit agencies, and such reviews could result in costs being disputed as nonreimbursable under the terms of the contract.

Time-and-Materials—Under time-and-materials contracts, hourly billing rates are negotiated and charged to clients based on the actual time spent on a project. In certain cases, these contracts may be subject to maximum contract values. In addition, clients reimburse actual out-of-pocket costs for materials and other direct incidental expenditures that are incurred in connection with the performance under the contract.

Fixed-Price—The Company enters into two types of fixed-price contracts: firm fixed-price (“FFP”) and fixed-price per unit (“FPPU”). Under FFP contracts, clients pay an agreed fixed-amount negotiated in advance for a specified scope of work.

Contract Costs—Contract costs consist of direct costs on contracts, including labor and materials, amounts payable to subcontractors, direct overhead costs and equipment expense (primarily depreciation, fuel, maintenance and repairs). All contract costs are recorded as incurred. Changes to estimated contract costs, either due to unexpected events or revisions to management’s initial estimates, for a given project are recognized in the period in which they are determined as estimated at the contract level. Pre-contract costs are expensed as incurred unless they are expected to be recovered from the client, generate or enhance resources that will be used in satisfying performance obligations in the future and directly relate to an existing or anticipated contract. Costs to mobilize equipment and labor to a job site, prior to substantive work beginning (“mobilization costs”) are capitalized as incurred and amortized over the expected duration of the contract. Additionally, the Company may incur incremental costs to obtain certain contracts, such as selling and market costs, bid and proposal costs, sales commissions, and legal fees, certain of which can be capitalized if they are recoverable under the contract. Capitalized contract costs are included in other current assets on the consolidated balance sheets and were not material as of December 31, 2018 and December 31, 2019.

Performance Obligations—A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account in ASC 606. The transaction price of a contract is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. To the extent a contract is deemed to have multiple performance obligations, the Company allocates the transaction price of the contract to each performance obligation using our best estimate of the standalone selling price of each distinct good or service in the contract. The Company determines the relative standalone selling price utilizing observable prices for the sale of the underlying goods or services. Contracts are considered to have a single performance obligation if the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts or is not distinct in the context of the contract, which is mainly because the Company provides a significant service of integrating a complex set of tasks and components into a single project or capability. Engineering and construction contracts are generally accounted for as a single performance obligation while our engineering and construction supervision contracts are accounted for as two separate performance obligations. When providing construction supervision services, the Company is not liable for the construction of the asset, but has an overall responsibility to oversee, coordinate, measure, and evaluate the quality of construction work and the performance of the construction contractor on behalf of the customer. Customers are generally billed as the Company satisfies its performance obligations and payment terms typically range from 30 to 120 days from the invoice date. Billings under certain fixed-price contracts may be based upon the achievement of specified milestones, while some arrangements may require advance customer payment. The Company’s contracts generally do not include a significant financing component.

Variable Consideration—The transaction price for the Company’s contracts may include variable consideration, which includes increases to transaction price for approved and unpriced change orders, claims and incentives, and reductions to transaction price for liquidated damages. Change orders, claims and incentives are generally not distinct from the existing contract due to the significant integration service provided in the context of the contract and are accounted for as a modification of the existing contract and performance obligation. The Company estimates variable consideration for a performance obligation utilizing one of the two prescribed methods, depending on which method better predicts the amount of consideration to which the Company will be entitled (or the amount the Company expects to incur in the case of liquidated damages). Such methods are: (a) the expected value method, whereby the amount of variable consideration to be recognized represents the sum of probability weighted amounts in a range of possible consideration amounts, and (b) the most likely amount method, whereby the amount of variable consideration to be recognized represents the single most likely amount in a range of possible consideration amounts. When applying these methods, the Company considers all information that is reasonably available, including historical, current and estimates of future performance. The expected value method is utilized in situations where a contract contains a large number of possible outcomes, while the most likely amount method is utilized in situations where a contract has only two possible outcomes.

The Company includes variable consideration in the estimated transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur or when the uncertainty associated with the variable consideration is resolved. The Company’s estimates of variable consideration and determination of whether to include estimated amounts in transaction price are based largely on an assessment of anticipated performance and all information (historical, current and forecasted) that is reasonably available. The effect of variable consideration on the transaction price of a performance obligation is recognized as an adjustment to revenue on a cumulative catch-up basis.

Change Orders—Change orders, which are a normal and recurring part of business, may include changes in specifications or design, manner of performance, facilities, equipment, materials, sites and period of completion of the work. The Company or customer may initiate change orders. Most change orders are not distinct from the existing contract and are accounted for as part of that existing contract. The effect of a change order on the transaction price and measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenues (either as an increase in or a reduction of revenues) on a cumulative catch-up basis. Revenues from unpriced change orders are recognized to the extent of the amounts the Company expects to recover, consistent with the variable consideration policy discussed above. If it is probable that a reversal of revenues will occur, the costs attributable to change orders are treated as contract costs without incremental revenues. To the extent change orders included in the price are not resolved in the Company’s favor, there could be reductions in, or reversals of previously reported amounts of, revenues and profits, and charges against current earnings, which could be material.

Claims Revenue—Claims are amounts in excess of agreed contract prices that the Company seeks to collect from clients or others for customer-caused delays, errors in specifications and designs, contract terminations, change orders that are in dispute, or other causes of unanticipated additional contract costs, including factors outside of our control, and therefore the Company believes it is entitled to additional compensation. Claims revenue, when recorded, is only recorded to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur. The Company includes certain claims in the transaction price when the claims are legally enforceable, the Company considers collection to be probable and believes it can reliably estimate the ultimate value. The Company continues to engage in negotiations with its customers on outstanding claims. However, these claims may be resolved at amounts that differ from current estimates, which could result in increases or decreases in future estimated contract profits or losses.

Warranties—In most cases, contracts include assurance-type warranties that the Company’s performance is free from material defect and consistent with the specifications of the Company’s contracts, which do not give rise to a separate performance obligation. To the extent the warranty terms provide the customer with an additional service, such as extended maintenance services, such warranty is accounted for as a separate performance obligation.

Revenue recognized over time—The Company’s performance obligations are generally satisfied over time as work progresses because of continuous transfer of control to the customer and the Company has the right to bill the customer as costs are incurred. Typically, revenue is recognized over time using an input measure (i.e.’ costs incurred to date relative to total estimated costs at completion) to measure progress. The Company generally uses the cost-to-cost measure of progress method because it best depicts the transfer of control to the customer which occurs as the Company incurs costs on its contracts. Under the cost-to-cost measure of progress method, the extent of progress towards completion is measured based on the ratio of total costs incurred to-date to the total estimated costs at completion of the performance obligation. Revenues, including estimated fees or profits, are recorded proportionally as costs are incurred. Any expected losses on construction-type contracts in progress are charged to earnings, in total, in the period the losses are identified. The Company recognizes adjustments in estimated profit on contracts under the cumulative catch-up method. Under this method, the impact of the adjustment on profit recorded to date is recognized in the period the adjustment is identified. Revenue and profit in future periods of contract performance is recognized using the adjusted estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, the Company recognizes the total loss in the period it is identified.

Right to invoice practical expedient—For performance obligations satisfied over time where the Company has a right to consideration from a customer in an amount that corresponds directly with the value of the Company’s performance to-date, the Company recognizes revenue in the amount to which it has a right to invoice. For the Company’s reimbursable services contracts, revenue is recognized using the right to invoice practical expedient, or on a cost-to-cost measure of progress method. The Company will select the method that best represents progress on a project.

Revenue recognized at a point in time—For performance obligations satisfied at a point in time, revenue is recognized when the services are performed, control is transferred, and the performance obligation is complete. The Company recognizes revenue at a point in time for vehicle inspection services. Revenue related to the inspection service is recognized for each vehicle inspection at the point the Company has completed the inspection.

In the Company’s industry, recognition of profit on long-term contracts requires the use of assumptions and estimates related to total contract revenue, total cost at completion, and the measurement of progress towards completion. Estimates are continually evaluated as work progresses and are revised when necessary. When a change in estimate is determined to have an impact on contract profit, the Company records a positive or negative adjustment to the consolidated statements of income.

Refer to the Recently Adopted Accounting Pronouncements for discussion of the differences between the current revenue recognition criteria under ASC 606 and the Company’s previous recognition practices under ASC 605, Revenue Recognition.

Cash Equivalents

The Company considers all highly liquid investments with original maturities of less than three months to be cash equivalents. Cash equivalent investments are carried at cost, which approximates fair value, and consist primarily of United States Treasuries, time deposits, and other forms of short-term fixed income investments.

Restricted Cash and Investments

Restricted cash and investments held in trust accounts represent collateral for certain incentive programs.

Accounts Receivable, Net

Accounts receivable includes billed and unbilled amounts and are recognized in the period when the Company’s rights to receive consideration are unconditional.

The Company establishes an allowance for doubtful accounts based on the assessment of the clients’ ability to pay. In addition to such allowances, there are often items in dispute or being negotiated that may require us to make an estimate as to the ultimate outcome. Past due receivable balances are written off when internal collection efforts have been unsuccessful in collecting the amounts due.

Contract Assets and Contract Liabilities

In connection with the adoption of ASC 606 on December 30, 2017, the Company revised its policy related to contract assets and contract liabilities.

Projects with performance obligations recognized over time that have revenue recognized to-date in excess of cumulative billings and unbilled accounts receivable are reported on our consolidated balance sheets as “Contract assets”. Contract retentions, included in contract assets, represent amounts withheld by clients, in accordance with underlying contract terms, until certain conditions are met or the project is completed. The operating cycle for certain long-term contracts may extend beyond one year, and, accordingly, collection of retainage on those contracts may extend beyond one year. Contract assets are reclassified to accounts receivable when the right to consideration becomes unconditional.

Contract liabilities on uncompleted contracts represent the excess of cash collected from clients and billings to clients on contracts in advance of work performed over the amount of revenue recognized and provisions for losses. The majority of these amounts are expected to be earned within 12 months and are classified as current liabilities.

Refer to the Recently Adopted Accounting Pronouncements for further discussion of the impact of adopting ASC 606.

Concentration of Credit Risk

Financial instruments which potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivables. The Company’s cash is primarily held with major banks and financial institutions throughout the world. At times, cash balances may be in excess of the amount insured.

The Company is involved in a significant volume of contracts with the United States federal government and state and local governments. Approximately 36%, 42% and 48% of consolidated revenues for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively, and approximately 29% and 18% of accounts receivable as of December 31, 2018 and December 31, 2019, respectively, were derived from contracts with the United States federal government. No other customers represented 10% or more of consolidated revenues or accounts receivable in any of the periods presented.

In order to mitigate the credit risk associated with customers, the Company performs periodic credit evaluations of its customers’ financial condition.

Property and Equipment

Property and equipment are stated at cost and are shown net of accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Depreciation of leasehold improvements is computed using the straight-line method over the shorter of their estimated useful lives or the remaining term of the lease.

The cost of assets retired or otherwise disposed of and the related accumulated depreciation are eliminated from the accounts, and any gain or loss thereon is included in net income. Expenditures for maintenance and repairs are expensed as incurred. Property and equipment are reviewed for impairment when events or circumstances change that indicate they may not be recoverable. Impairment losses are recognized when estimated future cash flows expected to result from the use of the assets and their eventual disposition are less than their carrying amount, in which case the asset is written down to its fair value.

Leases

The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease ROU assets and current and long-term operating lease liabilities in the consolidated balance sheets. Finance leases are included in other noncurrent assets, accrued expenses and other current liabilities and other long-term liabilities in the consolidated balance sheets.

ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, incremental borrowing rates are used based on the information available at commencement date in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term.

We have lease agreements with lease and non-lease components where the lease consideration is allocated between the components based on relative standalone prices. For real property leases, allocations of lease consideration between lease and non-lease components are immaterial. For certain equipment leases, such as vehicles, we account for the lease and non-lease components as a single lease component. Additionally, for certain equipment leases, we apply a portfolio approach to effectively account for the operating lease ROU assets and liabilities.

Equity-Based Compensation

The Company measures the value of services received from employees and directors in exchange for an equity-based award based on the grant date fair value. The Company issues equity-based awards that settle in either cash or shares of the Company’s common stock. Cash settled awards are subsequently remeasured to an updated fair value at each reporting period until the award is settled. Awards containing performance measures are adjusted at each reporting period for the number of shares expected to be earned. Compensation cost for cash settled and performance awards are trued-up at each reporting period for changes in fair value and expected shares pro-rated for the portion of the requisite service period rendered. The Company recognizes compensation costs for these awards on either a straight-line or accelerated basis over the vesting period of the award in indirect, general and administrative expense in the consolidated statements of income.

Business Combinations

The Company accounts for business combinations using the acquisition method, under which the purchase price of an acquired company is allocated to the tangible and intangible assets acquired and the liabilities assumed on the basis of their fair values at the date of acquisition. Any excess of purchase price over the fair value of tangible and intangible assets acquired and liabilities assumed is allocated to goodwill. The determination of fair values of assets acquired and liabilities assumed requires the Company to make estimates and use valuation techniques when a market value is not readily available. The Company adjusts the preliminary purchase price allocation, as necessary, during the measurement period of up to one year after the acquisition closing date as the Company obtains more information as to facts and circumstances existing at the acquisition date. Acquisition-related costs are recognized separate from the acquisition and are expensed as incurred.

Consolidation of Joint Ventures and Variable Interest Entities

The Company participates in joint ventures, which include partnerships and partially owned limited liability corporations, to bid, negotiate and complete specific projects. The Company is required to consolidate these joint ventures if it holds the majority voting interest or if the joint venture is determined to be a variable interest entity (“VIE”) for which the Company is the primary beneficiary, as described below.

A VIE is an entity with one or more of the following characteristics: (a) the total equity investment at risk is not sufficient to permit the entity to finance its activities without additional financial support; (b) as a group, the holders of the equity investment at risk lack the ability to make certain decisions, the obligation to absorb expected losses or the right to receive expected residual returns; or (c) an equity investor has voting rights that are disproportionate to its economic interest and substantially all of the entity’s activities are on behalf of the investor with disproportionately low voting rights. The Company’s VIEs may be funded through contributions, loans and/or advances from the joint venture partners or by advances and/or letters of credit provided by clients. Certain VIEs are directly governed, managed, operated and administered by the joint venture partners. Others have no employees and, although these entities own and hold the contracts with the clients, the services required by the contracts are typically performed by the joint venture partners or by other subcontractors.

The Company is considered the primary beneficiary and required to consolidate a VIE if it has the power to direct the activities that most significantly impact that VIE’s economic performance, and the obligation to absorb losses or the right to receive benefits of that VIE that could potentially be significant to the VIE. In determining whether the Company is the primary beneficiary, significant assumptions and judgments include the following: (1) identifying the significant activities and the parties that have the power to direct them; (2) reviewing the governing board composition and participation ratio; (3) determining the equity, profit and loss ratio; (4) determining the management-sharing ratio; (5) reviewing employment terms, including which joint venture partner provides the project manager; and (6) reviewing the funding and operating agreements. Examples of significant activities currently being performed by the Company’s significant consolidated and unconsolidated joint ventures include engineering and design services; management consulting services; procurement and construction services; program management; construction management; and operations and maintenance services. If the Company determines that the power to direct the significant activities is shared by two or more joint venture parties, then there is no primary beneficiary and no party consolidates the VIE. In making the shared-power determination, the Company analyzes the key contractual terms, governance, related party and de facto agency as they are defined in the accounting standard, and other arrangements.

Goodwill

In 2019, the Company changed the date of its annual goodwill impairment testing from November 30 to October 1. This change is results in better alignment of the Company's annual impairment test with the Company’s annual budgeting cycle and provides a more reliable measurement using the Company’s interim closing processes. The change had no effect on the Company’s financial statements for the current or historical periods.

The Company performs an additional review at year end to address the interim period.

For purposes of impairment testing, goodwill is allocated to the applicable reporting units based on the current reporting structure. The Company’s reporting units are operating segments or components of operating segments where discrete financial information is available and segment management regularly reviews the operating results. When evaluating goodwill for impairment, the Company may decide to first perform a qualitative assessment, or “step zero” impairment test, to determine whether it is more likely than not that impairment has occurred. If the Company does not perform a qualitative assessment, or if the Company determines that it is not more likely than not that the fair value of its reporting units exceeds their carrying amounts, the Company performs a quantitative assessment and calculates the estimated fair value of the respective reporting unit. If the carrying amount of a reporting unit exceeds its fair value, an impairment loss is recognized in the amount the carrying value exceeds its fair value, not to exceed the carrying amount of goodwill.

The Company’s decision to perform a qualitative impairment assessment in a given year is influenced by a number of factors, including the significance of the excess of the Company’s estimated fair value over carrying value at the last quantitative assessment date, the amount of time in between quantitative fair value assessments, and the date of its acquisitions, if any.

Intangible Assets

Intangible assets with finite lives arise from business acquisitions and are amortized based on the period over which the contractual or economic benefit of the intangible assets are expected to be realized or on a straight-line basis over the useful lives of the underlying assets, ranging from one to ten years. These primarily consist of customer relationships, developed technology, backlog, and covenants not to compete. When indicators of a potential impairment exist, the Company assesses the recoverability of the unamortized balance of its intangible assets by first comparing undiscounted expected cash flows associated with the asset, or the asset group they are part of, to its carrying value. Should the review indicate that the carrying value is not fully recoverable, the excess of the carrying value over the fair value of the intangible assets would be recognized as an impairment loss.

Income Taxes

Income taxes are accounted for under the asset and liability method. This approach requires the recognition of deferred tax liabilities and assets to reflect the tax effects of temporary differences between the financial statement carrying amounts and tax bases of the Company’s assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Deferred tax assets are evaluated for future realization and valuation allowances are established when, in our opinion, it is more likely than not that all or some portion of the asset will not be realized.

The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained on examination by the taxing authorities based on the technical merits of the position. The tax benefits recognized in the financial statements on a particular tax position are measured based on the largest benefit that is greater than 50 percent likely of being realized. The amount of unrecognized tax benefits (“UTB”) is adjusted as appropriate for changes in facts and circumstances, such as significant amendments to existing tax law, new regulations or interpretations by the taxing authorities, new information obtained during a tax examination, or resolution of an examination. The Company recognizes both accrued interest and penalties, where appropriate, related to UTBs in income tax expense.

Foreign Currency Translation

The Company’s reporting currency is the U.S. Dollar. The functional currency of the Company’s foreign entities is typically the currency of the primary environment in which they operate. For foreign entities whose functional currency is not the U.S. dollar, the assets and liabilities are translated based on exchange rates in effect at the balance sheet date, while the income and expense accounts are translated using the average exchange rates during the period. Translation gains or losses, net of income tax effects, are reflected in accumulated other comprehensive income on the consolidated balance sheets. Transaction gains and losses due to movements in exchange rates between the functional currency and the currency in which a foreign currency transaction is denominated are recognized as “Other income (expense), net” in the Company’s consolidated statements of income.

Self-Insurance

The Company typically utilizes third-party insurance subject to varying retention levels or self-insurance. The Company is self-insured for a portion of the losses and liabilities primarily associated with workers’ compensation, general, professional, automobile, employee matters, certain medical plans, and project-specific liability claims. Losses are accrued based upon the Company’s estimates of the aggregate liability for claims incurred using historical experience and certain actuarial assumptions, as provided by an independent actuary. The estimate of self-insurance liability includes an estimate of incurred but not reported claims, based on data compiled from historical experience.

Recently Adopted Accounting Pronouncements

The Company adopted ASC 606 on December 30, 2017, using the modified retrospective method, which provides for a cumulative effect adjustment to beginning 2018 accumulated deficit for those uncompleted contracts impacted by the adoption of the new standard. For contracts that were modified before the beginning of the earliest reporting period presented in accordance with ASC 606, the Company has not retrospectively restated the contract for those modifications. The Company instead reflected the aggregate effect of all modifications when identifying the satisfied and unsatisfied performance obligations, determining the transaction price and allocating the transaction price. The core principle of ASC 606 is that revenue will be recognized when promised goods or services are transferred to customers in an amount that reflects consideration for which entitlement is expected in exchange for those goods or services.

Additionally, the Company began to separately present contract assets and liabilities on the consolidated balance sheets. Contract assets include amounts due under contractual retainage provisions as well as revenue recognized to date in excess of cumulative billings and unconditional unbilled accounts receivable that were previously presented as unbilled accounts receivable. Contract liabilities include billings in excess of costs and estimated earnings as well as provisions for losses that were previously separately presented. The difference between the recognition criteria under ASC 606 and the Company’s previous recognition practices under the revenue recognition guidance, ASC Topic 605-35, was recognized through a cumulative effect adjustment that was made to the opening balance of accumulated deficit as of December 30, 2017. Consistent with the modified retrospective transition approach, the comparative fiscal 2017 period was not adjusted to conform to the fiscal 2018 and 2019 presentation.

The cumulative effect of adopting ASC 606 was primarily due to combining certain deliverables that were previously considered separate deliverables into a single performance obligation and the transition of certain cost-type contracts into the cost-to-cost measure of progress method.

The cumulative effect adjustment was an increase to accumulated deficit of $4.7 million as of December 30, 2017 as well as the following cumulative effect adjustments:

•

An increase to contract assets of $2.5 million;

•

An increase to deferred tax assets of $0.1 million;

•

An increase to contract liabilities of $7.2 million; and

•

An increase to non-controlling interests of $0.1 million.

In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842)”, which is a new standard related to leases intended to increase transparency and comparability among organizations by requiring the recognition of right-of-use (“ROU”) assets obtained in exchange for lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases.

The Company elected to adopt the standard, and available practical expedients, effective January 1, 2019. These practical expedients allowed the Company to keep the lease classification assessed under the previous lease accounting standard (ASC 840) without reassessment under the new standard, and allowed all separate lease components, including non-lease components, to be accounted for as a single lease component for all existing leases prior to adoption of the new standard. Furthermore, the Company made an accounting policy election to not recognize a lease liability and ROU asset for leases with lease terms of twelve months or less.

The Company adopted this new standard under the modified retrospective transition approach without adjusting comparative periods in the financial statements, as allowed under Topic 842, and implemented internal controls and key system functionality to enable the preparation of financial information on adoption.

The standard had a material impact on the Company’s consolidated balance sheets but did not have an impact on the consolidated statements of income and cash flows. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while accounting for finance leases remained substantially unchanged.

As a result of the adoption, the Company recorded a cumulative-effect adjustment to retained earnings of $52.6 million, net of deferred tax asset adjustment of $0.7 million, representing the unamortized portion of a deferred gain previously recorded as a sale-leaseback transaction associated with the sale of an office building in 2011. The Company concluded the transaction resulted in the transfer of control of the office building to the buyer-lessor at market terms and would have qualified as a sale under Topic 842 with gain recognition in the period the sale was recognized.

In July 2018, the FASB issued ASU No. 2018-09, Codification Improvements. The amendments in this ASU clarify certain aspects of the guidance related to: reporting comprehensive income, debt modification and extinguishment, income taxes related to stock compensation, income taxes related to business combinations, derivatives and hedging, fair value measurements, brokers and dealers liabilities, and plan accounting. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company has adopted this ASU on a prospective basis in the first quarter of 2019 and has determined there to be no impact on its financial statements and related disclosures.

Effective January 1, 2019, the Company adopted ASU 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” under which the Company did not elect to reclassify the income tax effects stranded in accumulated other comprehensive income to retained earnings as a result of the enactment of comprehensive tax legislation, commonly referred to as the Tax Cuts and Jobs Act. As a result, there was no impact on the Company’s financial position, results of operations or cash flows.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments,” and issued subsequent amendments to the initial guidance within ASU 2019-04 and ASU 2019-05. The amendments in ASU 2016-13 replace the incurred loss impairment methodology in current practice with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to estimate credit losses. ASU 2016-13 and its amendments are effective for interim and annual reporting periods beginning after December 15, 2019. This standard will be effective for the Company’s interim and annual periods beginning with the first quarter of fiscal 2020. Management continues to assess the impact of adopting ASU 2016-13 and does not believe it will have a material effect on the company’s financial position, results of operations and cash flows.

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 was issued as a means to reduce the complexity of accounting for income taxes for those entities that fall within the scope of the accounting standard. The guidance is to be applied using a prospective method, excluding amendments related to franchise taxes, which should be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company is evaluating the impact of ASU 2019-12 on its consolidated financial statements.

Acquisitions

12 Months Ended

Dec. 31, 2019

Business Combinations [Abstract]

Acquisitions

3.	Acquisitions

Williams Electric

On October 6, 2017, the Company completed the acquisition of Williams Electric Company, Inc., a specialty contractor delivering global control system integration and energy infrastructure solutions to U.S. Government customers. The total consideration for this acquisition, net of cash received, was approximately $25.7 million, which we paid in cash at closing.

Polaris Alpha

On May 31, 2018, the Company acquired a 100% ownership interest in Polaris Alpha, a privately-owned, advanced technology-focused provider of innovative mission solutions for complex defense, intelligence, and security customers, as well as other U.S. federal government customers, for $489.1 million paid in cash. The Company borrowed $260 million under the Credit Agreement, as described in “Note 12—Debt and Credit Facilities”, to partially fund the acquisition. In connection with this acquisition, the Company recognized $6.2 million of acquisition-related expenses in “Indirect, general and administrative expense” in the consolidated statements of income for the year ended December 31, 2018, including legal fees, consulting fees, and other miscellaneous direct expenses associated with the acquisition. Polaris Alpha enhances the Company’s artificial intelligence and data analytics expertise with new technologies and solutions. Customers of both companies will benefit from existing, complementary technologies and increased scale, enabling end-to-end solutions under the shared vision of rapid prototyping and agile development. The following table summarizes the fair values of the assets acquired and liabilities assumed as of the date of acquisition (in thousands):

	Polaris Alpha
Cash and cash equivalents	$	7,914
Accounts receivable		29,688
Contract assets		35,229
Prepaid expenses and other current assets		9,295
Property and equipment		9,024
Goodwill		243,471
Intangible assets		199,520
Other noncurrent assets		2,203
Accounts payable		(13,942	)
Accrued expenses and other current liabilities		(26,419	)
Contract liabilities		(3,529	)
Deferred tax liabilities		(2,231	)
Other long-term liabilities		(1,146	)
Net assets acquired	$	489,077

Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years):

	Gross Carrying Amount		Amortization Period
			(in years)
Developed technology	$	84,900		4
Customer relationships		76,000		8
Backlog		34,900		2
Trade name		3,600		1
Leases		120		6

Amortization expense of $30.3 million and $54.5 million related to these intangible assets was recorded for the years ended December 31, 2018 and December 31, 2019, respectively. The entire value of goodwill of $243.5 million was assigned to the Federal Solutions reporting unit and represents synergies expected to be realized from this business combination. Goodwill of $50.1 million is deductible for tax purposes.

The amount of revenue generated by Polaris Alpha since the acquisition and included within consolidated revenues for 2018 is $227.3 million. The Company has determined that the presentation of net income from the date of acquisition is impracticable due to the integration of general corporate functions upon acquisition.

Supplemental Pro Forma Information (Unaudited)

Supplemental information on an unaudited pro forma basis, as if the acquisition closed as of the beginning of the fiscal year ended December 29, 2017 as follows (in thousands):

	2017		2018
	(unaudited)		(unaudited)
Pro forma Revenue	$	3,361,626	$	3,713,804
Pro forma Net Income including noncontrolling interest		58,356		225,861

The unaudited pro forma supplemental information is based on estimates and assumptions which the Company believes are reasonable and reflects the pro forma impact of additional amortization related to the fair value of acquired intangible assets, the pro forma impact of reflecting acquisition costs, which consisted of legal, advisory and due diligence fees and expenses, and the additional pro forma interest expense related to the borrowings under the credit agreement as of the assumed acquisition date. This supplemental pro forma information has been prepared for comparative purposes and does not purport to be indicative of what would have occurred had the acquisition been consummated during the periods for which pro forma information is presented.

OGSystems

On January 7, 2019, the Company acquired a 100% ownership interest in OGSystems, a privately-owned company, for $292.4 million paid in cash. OGSystems provides geospatial intelligence, big data analytics and threat mitigation for defense and intelligence customers. The Company borrowed $110 million under the Credit Agreement and $150 million on a short-term loan, as described in “Note 12—Debt and Credit Facilities,” to partially fund the acquisition. In connection with this acquisition, the Company recognized $5.4 million of acquisition-related expenses in “Indirect, general and administrative expense” in the consolidated statements of income for the year ended December 31, 2019, including legal fees, consulting fees, and other miscellaneous direct expenses associated with the acquisition. OGSystems enhances the Company’s artificial intelligence and data analytics expertise with new technologies and solutions. Customers of both companies will benefit from existing, complementary technologies and increased scale, enabling end-to-end solutions under the shared vision of rapid prototyping and agile development.

The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on the purchase price allocation as of the date of acquisition (in thousands):

	Amount
Cash and cash equivalents	$	5,772
Accounts receivable		9,904
Contract assets		9,747
Prepaid expenses and other current assets		4,307
Property and equipment		4,085
Right of use assets, operating leases		8,826
Goodwill		183,540
Intangible assets		92,300
Other noncurrent assets		10
Accounts payable		(5,450	)
Accrued expenses and other current liabilities		(7,147	)
Contract liabilities		(1,300	)
Short-term lease liabilities, operating leases		(805	)
Income tax payable		(1,178	)
Deferred tax liabilities		(1,195	)
Long-term lease liabilities, operating leases		(8,021	)
Other long-term liabilities		(1,015	)
Net assets acquired	$	292,380

Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years):

	Gross Carrying Amount		Amortization Period
			(in years)
Customer relationships	$	57,100		5
Backlog		27,700		3
Trade name		3,800		2
Non-compete agreements		2,400		3
Developed technologies	$	1,300		3

Amortization expense of $23.8 million related to these intangible assets was recorded for the year ended December 31, 2019. The entire value of goodwill of $183.5 million was assigned to the Federal Solutions reporting unit and represents synergies expected to be realized from this business combination. Goodwill of $16 million is deductible for tax purposes.

The amount of revenue generated by OGSystems since the acquisition and included within consolidated revenues for year ended December 31, 2019 is $143.4 million. The Company has determined that the presentation of net income from the date of acquisition is impracticable due to the integration of general corporate functions upon acquisition.

Supplemental Pro Forma Information (Unaudited)

Supplemental information of unaudited pro forma operating results assuming the OGSystems acquisition had been consummated as of the beginning of fiscal year 2018 (December 30, 2017) (in thousands) is as follows:

	2018		2019
	(unaudited)		(unaudited)
Pro forma Revenue	$	3,676,894	$	3,956,767
Pro forma Net Income including noncontrolling interests		205,961		134,046

QRC Technologies

On July 31, 2019 the Company acquired a 100% ownership interest in QRC Technologies (“QRC”), a privately-owned company, for $214.1 million in cash. QRC provides design and development of open-architecture radio-frequency products. The Company borrowed $140.0 million under the Revolving Credit Facility to partially fund the transaction. In connection with this acquisition, the Company recognized $4.9 million of acquisition-related expenses in “Indirect, general and administrative expense” in the consolidated statements of income for the year ended December 31, 2019, including legal fees, consulting fees, and other miscellaneous direct expenses associated with the acquisition. QRC is an agile, disruptive product company that specializes in radio frequency spectrum survey, record and playback; signals intelligence; and electronic warfare missions. QRC complements our existing portfolio, increases our presence in the high-growth markets of spectrum awareness and surveillance, adds critical intellectual property that complements and expands our available capabilities for the Special Operations and Intelligence Communities.

The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on the preliminary purchase price allocation as of the date of acquisition (in thousands):

	Amount
Cash and cash equivalents	$	5,925
Accounts receivable		5,587
Prepaid expenses and other current assets		5,727
Property and equipment		1,205
Right of use assets, operating leases		5,228
Goodwill		125,091
Intangible assets		76,200
Accounts payable		(1,567	)
Accrued expenses and other current liabilities		(4,025	)
Short-term lease liabilities, operating leases		(545	)
Long-term lease liabilities, operating leases		(4,683	)
Net assets acquired	$	214,143

Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years):

	Gross Carrying Amount		Amortization Period
			(in years)
Customer relationships	$	49,800		12
Developed technologies		21,800	3 to 5
In-process research and development		1,800	3 to 5
Non-compete agreements		1,200		4
Trade name		800		2
Backlog		800		1

The Company is still in the process of finalizing its valuation of the net assets acquired.

Amortization expense of $5.7 million related to these intangible assets was recorded for the year ended December 31, 2019. The entire value of goodwill of $125.1 million was assigned to the Federal Solutions reporting unit and represents synergies expected to be realized from this business combination. Goodwill in its entirety is deductible for tax purposes.

The amount of revenue generated by QRC since the acquisition and included within consolidated revenues for the year ended December 31, 2019 is $11.2 million. The Company has determined that the presentation of net income from the date of acquisition is impracticable due to the integration of general corporate functions upon acquisition.

Supplemental Pro Forma Information (Unaudited)

Supplemental information of unaudited pro forma operating results assuming the QRC Technologies acquisition had been consummated as of the beginning of fiscal year 2018 (December 30, 2017) (in thousands) is as follows:

	2018		2019
	(unaudited)		(unaudited)
Pro forma Revenue	$	3,596,920	$	3,976,361
Pro forma Net Income		221,930		138,692

Contracts with Customers

12 Months Ended

Dec. 31, 2019

Revenue From Contract With Customer [Abstract]

Contracts with Customers

4.	Contracts with Customers

Disaggregation of Revenue

The Company’s contracts contain both fixed price and cost reimbursable components. Contract types are based on the component that represents the majority of the contract. The following table presents revenue disaggregated by contract type (in thousands):

	December 31, 2018		December 31, 2019
Cost plus	$	1,473,815	$	1,705,832
Time-and-Materials		961,759		1,074,037
Fixed price		1,124,934		1,174,943
Total	$	3,560,508	$	3,954,812

Refer to “Note 21—Segment Information” for the Company’s revenues by business lines.

Contract Assets and Contract Liabilities

Contract assets and contract liabilities balances at December 31, 2018 and December 31, 2019 were as follows (in thousands):

	December 31, 2018		December 31, 2019		$ change		% change
Contract assets	$	515,319	$	575,089	$	59,770		11.60	%
Contract liabilities		208,576		230,681		22,105		10.60	%
Net contract assets (liabilities)(1)	$	306,743	$	344,408	$	37,665		12.28	%

(1)

Total contract retentions included in net contract assets (liabilities) were $89.6 million as of December 31, 2018. Total contract retentions included in net contract assets (liabilities) were $85.5 million as of December 31, 2019, of which $41.7 million are not expected to be paid in fiscal 2020. Contract assets at December 31, 2018 and December 31, 2019 include approximately $47.1 million and $73.0 million, respectively, related to unapproved change orders, claims, and requests for equitable adjustment. For the years ended December 31, 2018 and December 31, 2019, no material losses were recognized related to the collectability of claims, unapproved change orders, and requests for equitable adjustment.

During the years ended December 31, 2018 and December 31, 2019, the Company recognized revenue of approximately $168.6 million and $129.9 million, respectively that was included in the corresponding contract liability balance at December 29, 2017 and December 31, 2018, respectively. The change in contract assets and contract liabilities was the result of normal business activity and not significantly impacted by other factors, except as follows:

	December 31, 2018		December 31, 2019
Acquired contract assets	$	35,229	$	9,747
Acquired contract liabilities		3,529		1,300
Change in the estimate of variable consideration		—		12,166
Reversal of provision for contract losses(1)	$	133,180	$	—

(1)	Reversal of provision for contract losses of $133.2 million, of which $55.1 million was recorded as an increase in revenue with the remainder recorded as other income.

There was no significant impairment of contract assets recognized during the years ended December 31, 2018 and December 31, 2019.

Revisions in estimates, such as changes in estimated claims or incentives, related to performance obligations partially satisfied in previous periods that individually had an impact of $5 million or more on revenue resulted in an increase in revenue of $12.1 million for the year ended December 31, 2019, and no impact for the year ended December 31, 2018.

Accounts Receivable, Net

Accounts receivable, net consisted of the following as of December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019
Billed	$	538,808		$	494,366
Unbilled		135,180			218,959
Total accounts receivable, gross		673,988			713,325
Allowance for doubtful accounts		(50,702	)		(41,833	)
Total accounts receivable, net	$	623,286		$	671,492

Billed accounts receivable represents amounts billed to clients that have not been collected. Unbilled accounts receivable represents amounts where the Company has a present contractual right to bill but an invoice has not been issued to the customer at the period-end date.

The allowance for doubtful accounts was determined based on consideration of trends in actual and forecasted credit quality of clients, including delinquency and payment history, type of client, such as a government agency or commercial sector client, and general economic conditions and particular industry conditions that may affect a client’s ability to pay.

Transaction Price Allocated to the Remaining Unsatisfied Performance Obligations

The Company’s remaining unsatisfied performance obligations (“RUPO”) as of December 31, 2019 represent a measure of the total dollar value of work to be performed on contracts awarded and in progress. The Company had $5.0 billion in RUPO as of December 31, 2019.

RUPO will increase with awards of new contracts and decrease as the Company performs work and recognizes revenue on existing contracts. Projects are included within RUPO at such time the project is awarded and agreement on contract terms has been reached. The difference between RUPO and backlog relates to unexercised option years that are included within backlog and the value of Indefinite Delivery/Indefinite Quantity (“IDIQ”) contracts included in backlog for which task orders have not been issued.

RUPO is comprised of: (a) original transaction price, (b) change orders for which written confirmations from our customers have been received, (c) pending change orders for which the Company expects to receive confirmations in the ordinary course of business, and (d) claim amounts that the Company has made against customers for which it has determined that it has a legal basis under existing contractual arrangements and a significant reversal of revenue is not probable, less revenue recognized to-date.

The Company expects to satisfy its RUPO as of December 31, 2019 over the following periods (in thousands):

	Within One Year		Within One to Two Years		Thereafter
Federal Solutions	$	1,207,900	$	451,278	$	176,103
Critical Infrastructure		1,634,625		632,273		859,966
Total RUPO	$	2,842,525	$	1,083,551	$	1,036,069

Leases

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

Leases

The Company has operating and finance leases for corporate and project office spaces, vehicles, heavy machinery and office equipment. Our leases have remaining lease terms of one year to 11 years, some of which may include options to extend the leases for up to five years, and some of which may include options to terminate the leases up to the seventh year. As of December 31, 2019, assets recorded under finance leases were $2.4 million and accumulated depreciation associated with finance leases was $0.7 million.

The components of lease costs for the year ended December 31, 2019 are as follows (in thousands):

	2019
Operating lease cost	$	70,112
Short-term lease cost		11,988
Amortization of right-of-use assets		746
Interest on lease liabilities		77
Sublease income		(3,620	)
Total lease cost	$	79,303

Supplemental cash flow information related to leases for the year ended December 31, 2019 is as follows (in thousands):

	2019
Operating cash flows for operating leases	$	62,714
Operating cash flows for financing activities		77
Financing cash flows from finance leases		863
Right-of-use assets obtained in exchange for new operating lease liabilities		299,503
Right-of-use assets obtained in exchange for new finance lease liabilities	$	3,124

Supplemental balance sheet and other information related to leases as of December 31, 2019 is as follows (in thousands):

	2019
Operating Leases:
Right-of-use assets	$	233,415
Lease liabilities:
Current	$	49,994
Long-term		203,624
Total operating lease liabilities	$	253,618
Finance Leases:
Other noncurrent assets	$	2,377
Accrued expenses and other current liabilities	$	1,075
Other long-term liabilities	$	1,202

Weighted Average Remaining Lease Term:
Operating leases	6 years
Finance leases	3 years
Weighted Average Discount Rate:
Operating leases		4.0	%
Finance leases		4.5	%

As of December 31, 2019, the Company has additional operating leases, primarily for office spaces, that have not yet commenced of $9.9 million. These operating leases will commence in 2020 with lease terms of 5 years to 7 years.

A maturity analysis of the future undiscounted cash flows associated with the Company’s operating and finance lease liabilities as of December 31, 2019 is as follows (in thousands):

	Operating Leases			Finance Leases
2020	$	58,412		$	1,152
2021		54,491			870
2022		48,454			326
2023		41,424			48
2024		30,945			—
Thereafter		49,727			—
Total lease payments		283,453			2,396
Less: imputed interest		(29,835	)		(119	)
Total present value of lease liabilities	$	253,618		$	2,277

Rental expense for the years ended December 29, 2017, December 31, 2018 and December 31, 2019 was $73.3 million, $79.8 million and $ 82.1 million, respectively, and is recorded in “Indirect, general and administrative expenses” in the consolidated statements of income.

Equity-Based Compensation

12 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Equity-Based Compensation

6.	Equity-Based Compensation

The Company issues stock-based awards through the Shareholder Value Plan, Long-Term Growth Plan, Restricted Award Plan, and Incentive Award Plan. Through these plans the Company may issue stock options (including incentive and non-qualified stock options), stock appreciation rights, restricted stock, restricted stock units, an “other” stock or cash-based awards, or a dividend equivalent award. The compensation expense for these awards is recorded in Indirect, general and administrative expenses” in the Company’s consolidated financial statements.

Stock-based compensation expense was $18.8 million, $16.3 million and $49.0 million for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively, net of recognized tax benefits of $0.2 million, $0.2 million and $16.7 million for the years ended 2017, 2018 and 2019, respectively. The tax benefit realized related to awards vested during the years ended 2017, 2018, and 2019 was $0.1 million, $0.2 million and $3.3 million, respectively. We recognize forfeitures as they occur.

With the adoption of the Incentive Award Plan on April 15, 2019, the Company has discontinued issuing awards under the other plans described above. Outstanding awards granted out of the discontinued plans will continue to vest and will settle in cash.

At December 31, 2019, the amount of compensation cost relating to non-vested awards not yet recognized in the consolidated financial statements is $16.5 million. The majority of these unrecognized compensation costs will be recognized by the 3rd quarter of fiscal 2020.

As discussed in “Note 1—Description of Operations”, the Company consummated its IPO on May 8, 2019. Subsequent to the IPO, the fair value of a share of the Company’s common stock is based on quoted prices on the NYSE. Please see “Note 19—Fair Value of Financial Instruments” for a description of how the fair value of a share of the Company’s common stock was determined prior to the IPO.

Stock Appreciation Rights

Stock Appreciation Rights (“SARs”) were issued under the Shareholder Value Plan (“SVP”). Outstanding awards provide a cash incentive based on the increase in the Company’s share price over a three-year period, multiplied by a number of phantom share units. If at the end of a performance cycle the Company’s share price has not increased, then no award payment will be made. The awards issued under the SVP are time-vested cash-settled SARs. The SARs vest at the end of three years and expense is recognized on an accelerated basis over the vesting period. The grant date fair value of the award is determined by using the Black-Scholes option-pricing model. SARs are remeasured, using the Black-Scholes option-pricing model, to an updated fair value at each reporting period until the award is settled. The fair value of the grant on the vesting date is determined based on the 60-trading day weighted average closing price of the Company’s common stock on the NYSE. Compensation cost is trued-up at each reporting period for changes in fair value pro-rated for the portion of the requisite service period rendered.

The following table presents the assumptions used in the Black-Scholes option-pricing model for SARs outstanding at the year-end measurement date:

	December 31, 2019
Dividend yield		0.0	%
Expected volatility		31.0	%
Risk-free interest rate		1.6	%
Expected term		1.0

The following table presents the number of SARs granted, vested, and forfeited for the years ended December 29, 2017, December 31, 2018, and December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at December 30, 2016		3,170,565		$	3.00
Granted		2,096,439		$	3.00
Vested		(1,573,998	)	$	3.00
Forfeited		(297,631	)	$	3.00
Unvested at December 29, 2017		3,395,375		$	3.00
Granted		1,708,746		$	3.00
Vested		(1,322,805	)	$	3.00
Forfeited		(364,662	)	$	3.00
Unvested at December 31, 2018		3,416,654		$	3.00
Granted		—		$	—
Vested		(1,547,142	)	$	3.00
Forfeited		(391,884	)	$	3.00
Unvested at December 31, 2019		1,477,628		$	3.00

Long-Term Growth Units

Long-Term Growth Units awards were issued under the Long-Term Growth Plan. Outstanding awards provide a cash incentive based on performance conditions. The grant date fair value of the award is based on fair value of the Company’s common stock on the grant day. These awards vest at the end of three years and expense is recognized on an accelerated basis over the vesting period subject to the probability of meeting the performance requirements and adjusted for the number of shares expected to be earned. Awards are remeasured to an updated fair value at each reporting period until the award is settled. The updated fair value is based on the 60-trading day weighted average closing price of the Company’s common stock on the NYSE on the last day of the reporting period. Compensation cost is trued-up at each reporting period for changes in fair value and expected shares pro-rated for the portion of the requisite service period rendered.

The following table presents the number of Long-Term Growth Units granted, vested, and forfeited (at target shares) for the years ended December 29, 2017, December 31, 2018, and December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at December 30, 2016		331,986		$	19.65
Granted		174,270		$	20.33
Vested		(176,781	)	$	19.33
Forfeited		(21,594	)	$	20.09
Unvested at December 29, 2017		307,881		$	20.18
Granted		144,777		$	22.67
Vested		(136,221	)	$	20.00
Forfeited		(16,656	)	$	20.27
Unvested at December 31, 2018		299,781		$	20.23
Granted		—		$	—
Vested		(137,760	)	$	20.33
Forfeited		(34,584	)	$	21.50
Unvested at December 31, 2019		127,437		$	21.45

Restricted Award Units

Restricted Award Units awards were issued under the Restricted Award Plan. Outstanding awards provide a cash incentive based on the fair value of the Company’s common stock on the vesting date. The grant date fair value of the award is based on the fair value of the Company’s common stock on the grant date. These awards vest and expense is recognized on an accelerated basis over the respective vesting periods. Awards are remeasured to an updated fair value at each reporting period until the award is settled. The updated fair value is based on the 60-trading day weighted average closing price of the Company’s common stock on the NYSE on the last day of the reporting period. Compensation cost is trued-up at each reporting period for changes in fair value pro-rated for the portion of the requisite service period rendered.

The following table presents the number of Restricted Award Units granted, vested, and forfeited for the years ended December 29, 2017, December 31, 2018, and December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at December 30, 2016		534,355		$	19.85
Granted		306,843		$	20.33
Vested		(135,982	)	$	19.53
Forfeited		(45,771	)	$	19.90
Unvested at December 29, 2017		659,445		$	20.14
Granted		262,140		$	22.67
Vested		(264,408	)	$	20.00
Forfeited		(67,827	)	$	20.34
Unvested at December 31, 2018		589,350		$	21.31
Granted		—		$	—
Vested		(281,805	)	$	20.33
Forfeited		(58,101	)	$	21.31
Unvested at December 31, 2019		249,444		$	22.40

The following table presents the amount paid for cash settled awards, by award type, for the years ended December 29, 2017, December 31, 2018, and December 31, 2019 (in thousands):

	December 29, 2017		December 31, 2018		December 31, 2019
Stock Appreciation Rights	$	170	$	4,576	$	5,261
Long-Term Growth		8,246		1,095		1,108
Restricted Award Units		2,635		4,439		5,537
Total	$	11,051	$	10,110	$	11,906

Restricted Stock Units

Restricted Stock Units awards are issued under the Incentive Award Plan and are settled by the issuance of the Company’s common stock. Outstanding awards have been granted based on either service or service and performance conditions. The fair value of the award is based on the closing price of the Company’s common stock on the grant date. Awards vest over three-year periods, either annually or cliff. Expense is recognized on an accelerated basis for awards with service conditions only and on a straight-line basis for awards that include performance conditions. Expense recognition of awards with performance criteria are subject to the probability of meeting the performance conditions and adjusted for the number of shares expected to be earned. Compensation cost for awards with performance conditions are trued-up at each reporting period for changes in the expected shares pro-rated for the portion of the requisite service period rendered.

The following table presents the number of shares of restricted stock units granted (at target shares for awards with performance conditions) for the year ended December 31, 2019:

December 31,

2019

Weighted Average Grant-Date Fair Value

Restricted Stock Units (service condition)

270,544

34.11

Restricted Stock Units (service and performance condition)

327,675

34.02

The number of units granted for awards with performance conditions in the above table is based on performance against the target amount. The number of shares ultimately issued, which could be greater or less than target, will be based on achieving specific performance conditions related to the awards.

The following table presents the number and weighted average grant-date fair value of restricted stock units (at target shares for awards with performance conditions) at December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Outstanding at December 31, 2018		-		$	-
Granted		598,219			34.06
Vested		(74,704	)		34.02
Forfeited		(16,875	)		34.02
Outstanding at December 31, 2019		506,640		$	34.07

For the year ended December 31, 2019, 74,704 shares of restricted stock units were issued, and 27,962 shares of common stock related to employee statutory income tax withholding were retired.

The following table presents the number of shares of restricted stock outstanding (at target shares for awards with performance conditions) at December 31, 2019:

December 31,

2019

Weighted Average Grant-Date Fair Value

Restricted Stock Units (service condition)

189,090

34.15

Restricted Stock Units (service and performance condition)

317,550

34.02

Goodwill

12 Months Ended

Dec. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Goodwill

The following table summarizes the changes in the carrying value of goodwill by reporting segment for fiscal years ended December 31, 2018 and December 31, 2019 (in thousands):

	December 29, 2017		Acquisitions		Foreign Exchange			December 31, 2018
Federal Solutions	$	422,439	$	244,402	$	—		$	666,841
Critical Infrastructure		74,347		—		(4,250	)		70,097
Total	$	496,786	$	244,402	$	(4,250	)	$	736,938

	December 31 , 2018		Acquisitions		Foreign Exchange		December 31, 2019
Federal Solutions	$	666,841	$	308,564	$	—	$	975,405
Critical Infrastructure		70,097		—		1,923		72,020
Total	$	736,938	$	308,564	$	1,923	$	1,047,425

For the years ended December 31, 2018 and December 31, 2019, the Company performed a quantitative analysis for all reporting units. It was determined that the fair value of all reporting units exceeded their carrying values. As a result, no goodwill impairments were identified for those periods.

Intangible Assets

12 Months Ended

Dec. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Intangible Assets

8.	Intangible Assets

The gross amount and accumulated amortization of acquired identifiable intangible assets with finite useful lives included in “Intangible assets, net” on the consolidated balance sheets were as follows (in thousands except for years):

	December 31, 2018							December 31, 2019
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted Average Amortization Period (in years)
Backlog	$	80,754	$	(58,295	)	$	22,459	$	109,255	$	(87,510	)	$	21,745		3
Customer relationships		121,629		(38,974	)		82,655		228,529		(67,809	)		160,720		7
Leases		670		(561	)		109		670		(580	)		90		5
Developed technology		87,839		(15,174	)		72,665		110,939		(40,749	)		70,190		4
Trade name		3,600		(2,100	)		1,500		8,200		(5,667	)		2,533		1
Non-compete agreements		—		—			—		3,600		(925	)		2,675		3
In process research and development		—		—			—		1,800		—			1,800	n/a
Other intangibles		—		—			—		275		(170	)		105		10
Total intangible assets	$	294,492	$	(115,104	)	$	179,388	$	463,268	$	(203,410	)	$	259,858

The aggregate amortization expense of intangible assets was $5.6 million, $37.4 million and $88.3 million for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively.

Estimated amortization expense in each of the next five years and beyond is as follows (in thousands):

2020	$	86,574
2021		81,591
2022		36,100
2023		23,549
2024		9,098
Thereafter		21,146
	$	258,058

Property and Equipment, Net

12 Months Ended

Dec. 31, 2019

Property Plant And Equipment [Abstract]

Property and Equipment, Net

9.	Property and Equipment, Net

Property and equipment consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019			Useful lives (years)
Building and leasehold improvements	$	54,348		$	81,065		1-15
Furniture and equipment		81,705			91,720		3-10
Computer systems and equipment		148,255			164,161		3-10
Construction equipment		12,074			11,765		5-7
		296,382			348,711
Less: Accumulated depreciation		(204,533	)		(225,960	)
Property and equipment, net	$	91,849		$	122,751

Depreciation expense of $29.4 million, $32.4 million and $37.3 million was recorded for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively.

Sale-Leasebacks

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

Sale-Leasebacks

10.	Sale-Leasebacks

During fiscal 2011, the Company consummated two sale-leaseback transactions associated with the sale of two office buildings from which the Company recognized a total gain in the consolidated statements of income of $106.7 million and a total deferred gain of $107.8 million. The current and long-term portion of the deferred gain had been recorded in “Accrued expenses and other current liabilities” and “Deferred gain resulting from sale-leaseback transactions” on the consolidated balance sheet as of December 31, 2018, respectively, and was being recognized ratably over the minimum lease terms to which they relate, as an offset to rental expense in “Indirect, general and administrative expenses” in the consolidated statements of income. Amortization of the deferred gain was $7.3 million for each of the years ended December 29, 2017 and December 31, 2018.

The deferred gain balance of $53.3 million as of December 31, 2018 was recognized as an adjustment to beginning accumulated deficit, net of a deferred tax asset adjustment of $0.7 million, during January 2019 in connection with the adoption of the new leasing standard. See “Note 5—Leases”.

Accrued Expenses and Other Current Liabilities

12 Months Ended

Dec. 31, 2019

Payables And Accruals [Abstract]

Accrued Expenses and Other Current Liabilities

11.	Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018		2019
Salaries and wages	$	50,991	$	46,685
Employee benefits		214,008		259,081
Self-insurance liability		29,682		29,997
Project cost accruals		183,362		217,729
Other accrued expenses		81,657		86,371
Total accrued expenses and other current liabilities	$	559,700	$	639,863

Debt and Credit Facilities

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Debt and Credit Facilities

12.	Debt and Credit Facilities

Long-term debt consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019
Revolving credit facility	$	180,000		$	—
Senior notes		250,000			250,000
Debt issuance costs		(836	)		(647	)
Long-term debt	$	429,164		$	249,353

In November 2017, the Company entered into an amended and restated Credit Agreement. The Company incurred approximately $2.0 million of costs in connection with this amendment. Under the agreement, the Company’s revolving credit facility was increased from $500 million to $550 million and the term of the agreement was extended through November 2022. The borrowings under the Credit Agreement bear interest, at the Company’s option, at either the Base Rate (as defined in the Credit Agreement), plus an applicable margin, or LIBOR plus an applicable margin. The applicable margin for Base Rate loans is a range of 0.125% to 1.00% and the applicable margin for LIBOR loans is a range of 1.125% to 2.00%, both based on the leverage ratio of the Company at the end of each fiscal quarter. The rates at December 31, 2018 and December 31, 2019 were 4.253% and 3.02%, respectively. Borrowings under this Credit Agreement are guaranteed by certain of the Company’s operating subsidiaries. Letters of credit commitments outstanding under this agreement aggregated approximately $49.8 million and $43.7 million at December 31, 2018 and December 31, 2019, respectively, which reduced borrowing limits available to the Company.

On July 1, 2014, the Company finalized a private placement whereby the Company raised an aggregate amount of $250.0 million in debt repayable as follows (in thousands):

Tranche	Debt Amount		Maturity Date	Interest Rate
Senior Note, Series A	$	50,000	July 15, 2021		4.44	%
Senior Note, Series B		100,000	July 15, 2024		4.98	%
Senior Note, Series C		60,000	July 15, 2026		5.13	%
Senior Note, Series D		40,000	July 15, 2029		5.38	%

The Company incurred approximately $1.1 million of debt issuance costs in connection with the private placement. On August 10, 2018, the Company finalized an amended and restated intercreditor agreement related to this private placement to more closely align certain covenants and definitions with the terms under the 2017 amended and restated Credit Agreement and incurred approximately $0.5 million of additional issuance costs. These costs are presented as a direct deduction from the debt on the face of the balance sheet. Interest expense related to the Senior Notes approximated $12.4 million for the years ended December 29, 2017, December 31, 2018 and December 31, 2019. The amortization of debt issuance costs and interest expense are recorded in “Interest expense” on the consolidated statements of income. The Company made interest payments related to the Senior Notes of approximately $12.4 million during the periods ended December 29, 2017, December 31, 2018 and December 31, 2019. Interest payable of approximately $5.7 million is recorded in “Accrued expenses and other current liabilities” on the consolidated balance sheets at December 31, 2018 and December 31, 2019, respectively, related to the Senior Notes.

The Credit Agreement and private placement includes various covenants, including restrictions on indebtedness, liens, acquisitions, investments or dispositions, payment of dividends and maintenance of certain financial ratios and conditions. The Company was in compliance with these covenants at December 31, 2018 and December 31, 2019.

During the year ended December 31, 2019, the Company’s term loan of $150 million was paid off.

The Company also has in place several secondary bank credit lines for issuing letters of credit, principally for foreign contracts, to support performance and completion guarantees. Letters of credit commitments outstanding under these bank lines aggregated approximately $223.0 million and $197.3 million at December 31, 2018 and December 31, 2019, respectively.

Using a discounted cash flow technique that incorporates a market interest yield curve with adjustments for duration, optionality, and risk profile, the Company has determined that the fair value (Level 2; see “Note 19—Fair Value of Financial Instruments” below) of its debt approximates the carrying value.

Amortization of debt issuance costs for all of the Company’s debt and credit facilities for the years ended December 29, 2017, December 31, 2018 and December 31, 2019 was $0.5 million, $0.7 million and $1.0 million, respectively.

Other Long-term Liabilities

12 Months Ended

Dec. 31, 2019

Other Liabilities Disclosure [Abstract]

Other Long-term Liabilities

13.	Other Long-term Liabilities

Other long-term liabilities consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018		2019
Self-insurance liability	$	99,813	$	102,521
Deferred rent		15,966		—
Reserve for uncertain tax positions		9,890		14,427
Finance lease obligations		935		1,202
Other long-term liabilities		1,259		7,554
Total other long-term liabilities	$	127,863	$	125,704

Refer to “Note 14—Income Taxes” for further discussion of the Company’s reconciliation of the beginning and ending balances of uncertain tax positions.

Income Taxes

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Income Taxes

14.	Income Taxes

Historically, the Company had elected to be taxed under the provisions of Subchapter “S” of the Internal Revenue Code for federal tax purposes. As a result, income was not subject to U.S. federal income taxes or state income taxes in those states where the “S” Corporation status is recognized. Therefore, previously, no provision or liability for federal or state income tax had been provided in the consolidated financial statements except for those states where the “S” Corporation status was not recognized, or where states imposed a tax on “S” Corporations. The provision for income tax in the historical periods prior to the IPO consists of these state taxes and taxes from certain foreign jurisdictions where the Company is subject to tax.

In connection with the Company’s IPO on May 8, 2019, the “S” Corporation status was terminated, and the Company is now treated as a “C” Corporation under the Internal Revenue Code. The termination of the “S” Corporation status was treated as a change in tax status for Accounting Standards Codification 740, Income Taxes. These rules require that the deferred tax effects of a change in tax status to be recorded to income from continuing operations on the date the “S” Corporation status terminates. The termination of the “S” Corporation election has had a material impact on the Company’s results of operations, financial condition, and cash flows as reflected in the December 31, 2019 consolidated financial statements. Income tax expense decreased in fiscal 2019 primarily due to a tax benefit recorded for the revaluation of our deferred tax assets and liabilities as a result of our conversion from “S” Corporation to a “C” Corporation. Going forward, the effective tax rate will increase, and net income will decrease as compared to the Company’s “S” Corporation tax years, since the Company is now subject to both U.S. federal and state corporate income taxes on its earnings.

The US government enacted comprehensive tax legislation on December 22, 2017, which is commonly referred to as the Tax Cuts and Jobs Act ("TCJA"). The TCJA significantly revised the U.S. corporate income tax regime by, among other things, lowering the U.S. corporate tax rate from 35% to 21% effective January 1, 2018. The TCJA also repealed the deduction for domestic production activities, limited the deductibility of certain executive compensation, and implemented a modified territorial tax system with the introduction of the Global Intangible Low-Taxed Income (“GILTI”) tax rules. The TCJA also imposes a one-time transition tax on deemed repatriation of historical earnings of foreign subsidiaries. As a Subchapter “S” corporation the TCJA had a limited effect on the Company’s 2018 effective tax rate. The Company calculated that as a “C” corporation in 2019, the provisions of TCJA, except for the statutory rate, did not have a material impact on the income tax provision. Under GAAP, the Company is allowed to make an accounting policy election of either: (i) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost ” method); or (ii) factoring such amounts into the Company’s measurement of its deferred taxes (the “deferred” method). For taxable income inclusions due to the GILTI tax rules, the Company has elected the period cost method and has included the impact in the estimated annual effective tax rate as of December 31, 2019.

For US corporate income tax purposes, the Company will apportion its 2019 taxable income ratably between the “S” Corporation and “C” Corporation periods, as allowed by law. This allocation of income will effectively result in a blended income tax rate for the 2019 year, as only the C corporation earnings will be subject to both U.S. federal and state corporate income tax while the “S” Corporation earnings will be subject to tax in those states that tax “S” Corporations or do not recognize “S” Corporation status.

The following table presents the components of our income from continuing operations before income taxes (in thousands):

	2017		2018		2019
United States earnings	$	85,913	$	205,418	$	6,762
Foreign earnings		47,088		54,385		60,480
	$	133,001	$	259,803	$	67,242

The income tax expense (benefit) attributable to income from continuing operations for the years ended December 29, 2017, December 31, 2018 and December 31, 2019 consists of the following (in thousands):

	2017			2018			2019
Current
Federal	$	-		$	-		$	22,865
State		1,579			1,536		$	10,428
Foreign		14,482			20,253			20,159
Total current income tax expense		16,061			21,789			53,452
Deferred
Federal		—			—			(97,299	)
State		(569	)		2,329			(27,432	)
Foreign		5,972			(3,751	)		1,393
Total deferred tax expense (benefit)		5,403			(1,422	)		(123,338	)
Total income tax expense (benefit)	$	21,464		$	20,367		$	(69,886	)

Income tax expense (benefit) was different from the amount computed by applying the United States federal statutory rate to pre-tax income from continuing operations as a result of the following (in thousands):

	2017					2018					2019
Income before income tax expense (benefit)	$	133,001				$	259,803				$	67,242
Tax at federal statutory tax rate		46,550		35	%		54,559		21	%		14,121		21	%
S- corporation exclusion		(25,109	)	(19	)%		(39,539	)	(15	)%		(4,875	)	(7	)%
State taxes, net of federal tax benefit		1,010		1	%		3,865		1	%		3,223		5	%
Change in tax status		—		—			—		—			(93,878	)	(140	)%
Change in valuation allowance		1,438		1	%		(2,215	)	(1	)%		4,502		7	%
Change in uncertain tax positions		(34	)	0	%		629		0	%		4,118		6	%
Foreign tax rate differential		(907	)	(1	)%		4,168		2	%		4,886		7	%
Foreign tax credits		—		—			—		—			(1,313	)	(2	)%
Transaction costs		—		—			—		—			1,052		1	%
Other permanent items, net		—		—			—		—			1,182		2	%
Noncontrolling interests		(4,960	)	(4	)%		(3,599	)	(1	)%		(2,282	)	(3	)%
Other, net		3,476		3	%		2,499		1	%		(622	)	(1	)%
Total income tax expense (benefit)	$	21,464		16	%	$	20,367		8	%	$	(69,886	)	(104	)%

The effective tax rate in 2019 decreased to (104%) from 8% in 2018. During fiscal 2019, the Company recorded $93.9 million of deferred tax benefit related to the remeasurement of its U.S. deferred tax assets and liabilities due to the change in tax status from an S Corporation to a C Corporation. This is subject to change based upon additional analysis performed with the filing of the return. The $93.9 million was recorded net of a $6.3 million charge for a valuation allowance primarily related to foreign tax credits. This tax benefit was partially offset by the impact in the percentage of pre-tax earnings subject to taxation as a result of our conversion from “S” Corporation to a “C” Corporation.

The effective tax rate for the year ended December 31, 2019 differs from the federal statutory tax rate primarily due to the impact of the change in tax status from “S” Corporation to “C” Corporation, change in uncertain tax positions, jurisdictional mix of income, and change in valuation allowance. The effective tax rate for 2017 and 2018 differs from the federal statutory rate primarily as a result of the “S” Corporation status.

The components of deferred tax assets and liabilities consists of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019
Deferred tax assets
Project and non-project reserves	$	2,326		$	34,225
Employee compensation and benefits		1,609			59,624
Revenue and cost recognition		—			33,588
Insurance accruals		962			19,204
Net operating losses		14,855			16,400
Lease liabilities		205			68,447
Tax credit carryforwards		377			8,969
Other		2,240			3,318
Valuation allowance		(6,668	)		(17,358	)
Total deferred tax assets		15,906			226,417
Deferred tax liabilities
Intangible assets		(2,529	)		(29,543	)
Right of use assets		—			(63,032	)
Revenue and cost recognition		(10,570	)		—
Other		(3,367	)		(13,063	)
Total deferred tax liabilities		(16,466	)		(105,638	)
Net deferred tax (liability) asset	$	(560	)	$	120,779

The Company assesses the realizability of its deferred tax assets each reporting period through an analysis of potential sources of taxable income, including prior year taxable income available to absorb a carryback of tax losses, reversals of existing taxable temporary differences, tax planning strategies, and forecasts of taxable income. The Company considers all negative and positive evidence, including the weight of the evidence, to determine if valuation allowance against deferred tax assets are required. A valuation allowance is recorded against deferred tax assets to reflect the amount of deferred tax assets that is determined to be more-likely-than-not to be realized.

The tax cost, net of applicable credits, have been provided on the undistributed earnings of the Company’s foreign subsidiaries. The Company does not assert any earnings to be permanently reinvested.

As of December 31, 2018, and December 31, 2019, the Company’s valuation allowance against deferred tax assets is $6.7 million and $17.4 million, respectively. This valuation allowance represents the portion of deferred tax assets primarily related to foreign net operating loss carryforwards, foreign tax credit carryforwards and capital loss carryforwards for which the Company has determined are not more-likely-than-not to be realized. From December 31, 2018 to December 31, 2019, the Company’s valuation allowance increased by $10.7 million. Of this increase, $8.1 million relates to deferred tax assets recorded for foreign tax credit carryforwards. Due to the change in tax status, the Company determined it was more beneficial to claim foreign tax credits than foreign tax deductions. However, the valuation allowance is generated because the Company does not and will not have sufficient foreign source income to support the foreign tax credit carryforwards.

As of December 31, 2019, the Company had net operating loss carryforwards (“NOLs”) of $29.7 million, $28.2 million, and $41.5 million for U.S. Federal, U.S. states, and foreign jurisdictions, respectively. The utilization of the U.S. federal and U.S. state NOLs are subject to certain annual limitations. Of these amounts, $29.7 million, $26.6 million and $35.5 million in U.S. federal, U.S. states and foreign jurisdictions, respectively, do not expire. The remaining amounts of NOLs in U.S. states and in foreign jurisdictions will expire if not used between 2020 and 2040.

As of December 31, 2019, the Company has foreign tax credit carryforwards of $8.5 million. The Company has provided a valuation allowance of $8.5 million as the Company considers that these credits will not be realized. These foreign tax credits start expiring in the year 2029.

The Company conducts business globally and, as a result, the Company or one or more of its subsidiaries file income tax returns in the U.S. federal jurisdiction, various U.S. states, and foreign jurisdictions. The Company is subject to examination by tax authorities in several jurisdictions, including major jurisdictions such as Canada, Mexico, Qatar, Saudi Arabia and the United States.

A reconciliation of the beginning and ending balances of unrecognized tax benefits is as follows (in thousands):

	2017			2018			2019
Beginning of year	$	7,827		$	7,137		$	7,845
Increases—current year tax positions		1,134			1,094			7,531
Increases—prior year tax positions		319			1,301			1,379
Decreases—prior year tax positions		(1,629	)		(1,656	)		(991	)
Settlements		(361	)		—			(124	)
Lapse of statute of limitations		(153	)		(31	)		(114	)
End of year	$	7,137		$	7,845		$	15,526

At December 31, 2018, and December 31, 2019, there are $9.9 million and $13.9 million of unrecognized tax benefits that if recognized would affect the effective tax rate.

The Company recognizes interest and penalties related to unrecognized tax benefits as part of its income tax expense. During the years ended December 31, 2018 and December 31, 2019, the Company recognized approximately $0.1 million and $1.3 million, respectively, in interest and penalties. The amount of interest and penalties accrued was $1.9 million, $2.0 million, and $3.4 million for 2017, 2018, and 2019, respectively.

As of December 31, 2019, the Company’s U.S. federal income tax returns for tax years 2016 and forward remain subject to examination. U.S. states and foreign income tax returns remain subject to examination based on varying local statutes of limitations.

The Company does not anticipate a material change within twelve months as a result of concluding various tax audits and closing tax years. Although the Company believes its reserves for its tax positions are reasonable, the final outcome of tax examination could be materially different, both favorably and unfavorably. It is reasonably possible that these examinations may conclude in the next 12 months and that the unrecognized tax benefits the Company has recorded in relation to these tax years may change compared to the liabilities recorded for these periods. However, it is not currently possible to estimate the amount, if any, of such change.

Contingencies

12 Months Ended

Dec. 31, 2019

Commitments And Contingencies Disclosure [Abstract]

Contingencies

15.	Contingencies

The Company is subject to certain lawsuits, claims and assessments that arise in the ordinary course of business. Additionally, the Company has been named as a defendant in lawsuits alleging personal injuries as a result of contact with asbestos products at various project sites. Management believes that any significant costs relating to these claims will be reimbursed by applicable insurance and, although there can be no assurance that these matters will be resolved favorably, management believes that the ultimate resolution of any of these claims will not have a material adverse effect on our consolidated financial position, results of operations, or cash flows. A liability is recorded when it is both probable that a loss has been incurred and the amount of loss or range of loss can be reasonably estimated. When using a range of loss estimate, the Company records the liability using the low end of the range. The Company records a corresponding receivable for costs covered under its insurance policies. Management judgment is required to determine the outcome and the estimated amount of a loss related to such matters. Management believes that there are no claims or assessments outstanding which would materially affect the consolidated results of operations or the Company’s financial position.

On or about March 1, 2017, the Peninsula Corridor Joint Powers Board, or the JPB, filed a lawsuit against Parsons Transportation Group, Inc., or PTG, in the Superior Court of California, County of San Mateo, in connection with a positive train control project on which PTG was engaged prior to termination of its contract by the JPB. PTG had previously filed a lawsuit against the JPB for breach of contract and wrongful termination. The JPB seeks damages in excess of $100.0 million, which the Company is currently disputing. In addition to filing a complaint for breach of contract and wrongful termination, the Company has denied the allegations raised by the JPB and, accordingly, filed affirmative defenses. The Company is currently defending against the JPB’s claims and the parties are still engaged in discovery. The Company also has a professional liability insurance policy to the extent the JPB proves any errors or omissions occurred. At this time, the Company is unable to determine the probability of the outcome of the litigation or determine a potential range of loss, if any. The Company has also filed a third-party claim against a subcontractor for indemnification in connection with this matter.

In September 2015, a former Parsons employee filed an action in the United States District Court for the Northern District of Alabama against us as a qui tam relator on behalf of the United States (the “Relator”) alleging violation of the False Claims Act. The United States government did not intervene in this matter as it is allowed to do so under the statute. The Company filed a motion to dismiss the lawsuit on the grounds that the Relator did not meet the applicable statute of limitations. The District Court granted the motion to dismiss. The Relator’s attorney appealed the decision to the United States Court of Appeals of the Eleventh Circuit, which ultimately ruled in favor of the Relator, and the Company petitioned the United States Supreme Court to review the decision. The Supreme Court reviewed the decision and accepted the position of the Relator. The case was thus remanded to the United States District Court for the Northern District of Alabama. The defendants, including Parsons, will file appropriate pleadings opposing the allegations. At this time, the Company is unable to determine the probability of the outcome of the litigation or determine a potential range of loss, if any.

On or about October 4, 2019, LBH Engineers, LLC (“LBH”) filed a lawsuit against Parsons, PTG, and various other parties in the US District Court of for the Northern District of Georgia, in connection with an alleged infringement of LBH’s patent. LBH seeks damages and costs incurred by LBH, a post-judgment royalty, treble damages if the infringement is found to be willful, among other damages, which the Company and the other defendants are currently disputing. At this time, the Company is unable to determine the probability of the outcome of the litigation or determine a potential range of loss, if any.

Federal government contracts are subject to audits, which are performed for the most part by the Defense Contract Audit Agency (“DCAA”). Audits by the DCAA and other agencies consist of reviews of our overhead rates, operating systems and cost proposals to ensure that we account for such costs in accordance with the Cost Accounting Standards (“CAS”). If the DCAA determines we have not accounted for such costs in accordance with the CAS, the DCAA may disallow these costs. The disallowance of such costs may result in a reduction of revenue and additional liability for the Company. Historically, the Company has not experienced any material disallowed costs as a result of government audits. However, the Company can provide no assurance that the DCAA or other government audits will not result in material disallowances for incurred costs in the future. All audits of costs incurred on work performed through 2010 have been closed, and years thereafter remain open.

Although there can be no assurance that these matters will be resolved favorably, management believes that their ultimate resolution will not have a material adverse impact on the Company’s consolidated financial position, results of operations, or cash flows.

Retirement and Other Benefit Plans

12 Months Ended

Dec. 31, 2019

Compensation And Retirement Disclosure [Abstract]

Retirement and Other Benefit Plans

16.	Retirement and Other Benefit Plans

The Company’s principal retirement benefit plan is the ESOP, a stock bonus plan, established in 1975 to cover eligible employees of the Company and certain affiliated companies. Contributions of treasury stock to ESOP are made annually in amounts determined by the Company’s board of directors and are held in trust for the sole benefit of the participants. Shares allocated to a participant’s account are fully vested after six years of credited service, or in the event(s) of reaching age 65, death or disability while an active employee of the Company. As of December 31, 2018, all 78,172,809 outstanding shares of the Company’s common stock were held by the ESOP and recorded at their redemption value of $1.9 billion. As of December 31, 2019, the total shares of the Company’s common stock outstanding were 100,669,694, of which 78,896,806 were held by the ESOP.

A participant’s interest in their ESOP account is redeemable upon certain events, including retirement, death, termination due to permanent disability, a severe financial hardship following termination of employment, certain conflicts of interest following termination of employment, or the exercise of diversification rights. Prior to the IPO, participants’ interests were redeemable in cash based on share prices established by the ESOP Trustee. Subsequent to the IPO and during the 180-day lock-up period, participants’ interests were redeemable in cash based on quoted prices of a share of the Company’s common stock on the NYSE. Subsequent to the 180-day lock-up period, distributions from the ESOP of participants’ interests are made in the Company’s common stock based on quoted prices of a share of the Company’s common stock on the NYSE. A participant will be able to sell such shares of common stock in the market, subject to any requirements of the federal securities laws.

Prior to the end of the 180-day lock-up period. under the terms of the ESOP plan, for participants who held shares that were not readily tradeable, the Company was obligated to redeem eligible participants’ interests in their ESOP accounts for cash upon an employee’s election. At December 31, 2018, the Company presented all shares held by the ESOP as temporary equity on the consolidated balance sheet at redemption value as they included a cash redemption feature that was not solely within the Company’s control. At the conclusion of the 180-day lock-up period ESOP distributions are no longer made in cash and are now made in shares of the Company’s common stock. At December 31, 2019, shares held by the ESOP have been reclassified from temporary equity to permanent equity on the consolidated balance sheet.

Total ESOP contribution expense was approximately $40.6 million, $45.2 million and $55.5 million for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively, and is recorded in “Direct costs of contracts” and “Indirect, general and administrative expense” in the consolidated statements of income (loss).

At December 31, 2018 and December 31, 2019, 78,172,809 shares and 78,896,806 shares of the Company’s stock were held by the ESOP, respectively, which were recorded at redemption value of $1.9 billion at December 31, 2018 and within permanent equity post lock-up period at December 31, 2019. On April 3, 2019, the board of directors of the Company declared a cash dividend to the Company’s sole existing shareholder at that time, the ESOP, in the amount of $2.00 per share, or $52.1 million in the aggregate (the “IPO Dividend”). The IPO Dividend was paid on May 10, 2019. On April 15, 2019, the board of directors of the Company declared the Stock Dividend in a ratio of two shares of common stock for every one share of common stock then held by the Company’s shareholder. The record date of the Stock Dividend was May 7, 2019, the day immediately prior to the consummation of the Company’s IPO on May 8, 2019, and the payment date of the Stock Dividend was May 8, 2019. Purchasers of the Company’s common stock in the Company’s public offering were not entitled to receive any portion of the Stock Dividend. During the years ended December 29, 2017 and December 31, 2018, the Company did not declare any dividends.

The Company also maintains a defined contribution plan (the “401(k) Plan”). Substantially all domestic employees are entitled to participate in the 401(k) Plan, subject to certain minimum requirements. The Company’s contributions to the 401(k) Plan for the years ended December 29, 2017, December 31, 2018 and December 31, 2019 amounted to $15.8 million, $17.1 million and $25.2 million, respectively.

As part of an acquisition in 2014, the Company acquired a defined contribution pension plan, a defined benefit pension plan, and supplemental retirement plan. For the defined contribution pension plan, the Company contributes a base amount plus an additional amount based upon a predetermined formula. At December 31, 2018 and December 31, 2019, the defined benefit pension plan was in a net asset position of $1.7 million and $2.1 million, respectively, which is recorded in “Other noncurrent assets” on the consolidated balance sheet.

Investments in and Advances to Joint Ventures

12 Months Ended

Dec. 31, 2019

Equity Method Investments And Joint Ventures [Abstract]

Investments in and Advances to Joint Ventures

17.	Investments in and Advances to Joint Ventures

The Company participates in joint ventures to bid, negotiate and complete specific projects. The Company is required to consolidate these joint ventures if it holds the majority voting interest or if the Company meets the criteria under the consolidation model, as described below.

The Company performs an analysis to determine whether its variable interests give the Company a controlling financial interest in a VIE for which the Company is the primary beneficiary and should, therefore, be consolidated. Such analysis requires the Company to assess whether it has the power to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE.

The Company analyzed all of its joint ventures and classified them into two groups: (1) joint ventures that must be consolidated because they are either not VIEs and the Company holds the majority voting interest, or because they are VIEs and the Company is the primary beneficiary; and (2) joint ventures that do not need to be consolidated because they are either not VIEs and the Company holds a minority voting interest, or because they are VIEs and the Company is not the primary beneficiary.

Many of the Company’s joint venture agreements provide for capital calls to fund operations, as necessary; however, such funding is infrequent and is not anticipated to be material.

Letters of credit outstanding described in ‘Note 12—Debt and Credit Facilities” that relate to project ventures are approximately $76.8 million and $55.0 million at December 31, 2018 and December 31, 2019, respectively.

In the table below, aggregated financial information relating to the Company’s joint ventures is provided because their nature, risk and reward characteristics are similar. None of the Company’s current joint ventures that meet the characteristics of a VIE are individually significant to the consolidated financial statements.

Consolidated Joint Ventures

The following represents financial information for consolidated joint ventures included in the consolidated financial statements as or and for the years ended December 31, 2018 and December 31, 2019 (in thousands):

	2018		2019
Current assets	$	287,227	$	255,167
Noncurrent assets		2,689		2,860
Total assets		289,916		258,027
Current liabilities		199,833		193,583
Total liabilities		199,833		193,583
Total joint venture equity	$	90,083	$	64,444

	2017		2018		2019
Revenue	$	446,506	$	540,345	$	473,486
Costs		426,245		376,628		435,947
Net income	$	20,261	$	163,717	$	37,539
Net income attributable to noncontrolling interests	$	14,211	$	17,099	$	16,594

The assets of the consolidated joint ventures are restricted for use only by the particular joint venture and are not available for the Company’s general operations.

2018 includes reversal of a provisions related to a lawsuit against a joint venture in which the Company is the managing partner. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a description of this matter, which was resolved in favor of the Company on June 13, 2018.

Unconsolidated Joint Ventures

The Company accounts for its unconsolidated joint ventures using the equity method of accounting. Under this method, the Company recognizes its proportionate share of the net earnings of these joint ventures as “Equity in earnings (loss) of unconsolidated joint ventures” in the consolidated statements of income. The Company’s maximum exposure to loss as a result of its investments in unconsolidated VIEs is typically limited to the aggregate of the carrying value of the investment and future funding commitments.

The following represents the financial information of the Company’s unconsolidated joint ventures as presented in their unaudited financial statements as or and for the years ended December 31, 2018 and December 31, 2019 (in thousands):

	2018		2019
Current assets	$	707,457	$	801,335
Noncurrent assets		876,385		564,160
Total assets		1,583,842		1,365,495
Current liabilities		560,306		655,495
Noncurrent liabilities		813,269		507,131
Total liabilities		1,373,575		1,162,626
Total joint venture equity	$	210,267	$	202,869
Investments in and advances to unconsolidated joint ventures	$	63,560	$	68,620

	2017		2018		2019
Revenue	$	2,114,903	$	1,773,037		2,081,341
Costs		1,988,569		1,661,232		1,903,582
Net income	$	126,334	$	111,805		177,759
Equity in earnings of unconsolidated joint ventures	$	40,086	$	36,915		41,721

The Company received net distributions from its unconsolidated joint ventures of $31.8 million, $41.9 million and $38.9 million for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively.

Related Party Transactions

12 Months Ended

Dec. 31, 2019

Related Party Transactions

18.	Related Party Transactions

The Company often provides services to unconsolidated joint ventures and revenues include amounts related to recovering overhead costs for these services. For the years ended December 29, 2017, December 31, 2018 and December 31, 2019, revenues included $112.1 million, $144.7 million and $157.3 million, respectively, related to services the Company provided to unconsolidated joint ventures. For the years ended December 29, 2017, December 31, 2018 and December 31, 2019, the Company incurred approximately $81.8 million, $111.1 million and $119.1 million, respectively, of reimbursable costs. Amounts included in the consolidated balance sheets related to services the Company provided to unconsolidated joint ventures is as follows (in thousands):

	2018		2019
Accounts receivable	$	38,742		37,425
Contract assets		2,648		6,955
Contract liabilities	$	10,861		4,509

Fair Value of Financial Instruments

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

19.	Fair Value of Financial Instruments

The authoritative guidance on fair value measurement defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (referred to as an “exit price”). At December 31, 2018 and December 31, 2019, the Company’s financial instruments include cash, cash equivalents, accounts receivable, accounts payable, and other liabilities. The fair values of these financial instruments approximate their carrying values due to their short-term maturities.

Investments measured at fair value are based on one or more of the following three valuation techniques:

•

Market approach—Prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities;

•

Cost approach—Amount that would be required to replace the service capacity of an asset (i.e., replacement cost); and

•

Income approach—Techniques to convert future amounts to a single present amount based on market expectations (including present value techniques, option-pricing models and lattice models).

In addition, the guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets and liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are:


Level 1	Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets and liabilities;

Level 2	Pricing inputs that include quoted prices for similar assets and liabilities in active markets and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the derivative instrument; and

Level 3	Prices or valuations that require inputs that are both significant to the fair value measurements and unobservable.

The methods described above may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

The following table sets forth assets associated with the pension plan in “Note 16—Retirement and Other Benefits Plans” that are accounted for at fair value by Level within the fair value hierarchy.

Fair value as of December 31, 2018 (in thousands):

	Level 1		Level 2		Level 3		Total
Mutual funds	$	2,539	$	—	$	—	$	2,539
Fixed income		—		10,168		—		10,168
Cash and cash equivalents		361		—		—		361
	$	2,900	$	10,168	$	—	$	13,068

Fair value as of December 31, 2019 (in thousands):

	Level 1		Level 2		Level 3		Total
Mutual funds		2,987		—		—		2,987
Fixed income		—		10,447		—		10,447
Cash and cash equivalents		334		—		—		334
		3,321		10,447		—		13,768

As described in “Note 16—Retirement and Other Benefits Plans”, the Company acquired a defined contribution pension plan, a defined benefit pension plan, and supplemental retirement plans. At December 31, 2018 and December 31, 2019, the Company measured the mutual funds held within the defined benefit pension plan at fair value using unadjusted quoted prices in active markets that are accessible for identical assets. The Company measured the fixed income securities using market bid and ask prices. The inputs that are significant to the valuation of fixed income securities are generally observable, and therefore have been classified as Level 2.

The following table sets forth redeemable common stock associated with the ESOP in “Note 16—Retirement and Other Benefits Plans” that is accounted for at fair value by Level within the fair value hierarchy.

Fair value as of December 31, 2018 (in thousands):

	Level 1		Level 2		Level 3		Total
Redeemable Common Stock	$	—	$	—	$	1,876,309	$	1,876,309
	$	—	$	—	$	1,876,309	$	1,876,309

As described in “Note 16—Retirement and Other Benefits Plans”, the Company was obligated to redeem eligible participants’ interests in their ESOP accounts for cash upon an employee’s election until the conclusion of the 180-day lock-up period on November 3, 2019. Prior to the conclusion of the 180-day lock-up period, all shares held by the ESOP were redeemable in the future for cash at the option of the holder once vesting and eligibility requirements had been met. At December 31, 2018, 78,172,809 shares of the Company’s common stock were held by the ESOP which the Company recorded at their redemption values of $1.9 billion and presented as temporary equity on the consolidated balance sheet. The redemption value was based on a share price established by the ESOP trustee, taking into account, among other things, the advice of a third-party valuation consultant for the ESOP trustee, as well as the ESOP trustee’s knowledge of the Company. The share price valuation was determined using a combination of income- and market-based methods that utilized unobservable Level 3 inputs, including significant assumptions such as forecasted revenue and operating margins, working capital requirements, and weighted average cost of capital. At December 31, 2019, all outstanding shares of common stock are included in permanent equity in the consolidated balance sheet.

The following table presents a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3) (in thousands):

	2018			2019
Balance at beginning of year	$	1,855,305			1,876,309
Purchases of treasury stock		(125,814	)		(6,219	)
Contributions of treasury stock to ESOP		47,043			—
Share price adjustment		99,775			883,436
Transfer to permanent equity		—			(2,753,526	)
Balance at end of year	$	1,876,309			—

With respect to equity-based compensation, we estimate the fair value of SARs using the Black-Scholes option-pricing model. Like all option-pricing models, the Black-Scholes option-pricing model requires the use of subjective assumptions, including (i) the expected volatility of the market price of the underlying stock, and (ii) the expected term of the award, among others. Accordingly, changes in assumptions and any subsequent adjustments to those assumptions can cause different fair values to be assigned to SARs. Fair value for cash settled awards (excluding SARs prior to vesting) is determined based on the 60-trading day weighted average closing price of the Company’s common stock on the NYSE at the end of each reporting period and on the vesting date. For restricted stock units containing service conditions or service and performance conditions, fair value is based on the closing stock price of a share of the Company’s common stock on the NYSE on the grant date.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Earnings Per Share

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Earnings Per Share

20.	Earnings Per Share

Basic earnings per common share is computed using the weighted average number of shares outstanding during the period and income available to shareholders.

Diluted EPS is computed similar to basic EPS, except the weighted average number of shares outstanding is increased to include the dilutive effects of outstanding stock options and other stock-based awards. There were no dilutive securities outstanding during 2017 and 2018.

The weighted average number of shares used to compute basic and diluted EPS were (in thousands):

	2017		2018		2019
Basic weighted average number of shares outstanding		83,574		80,014		92,419
Dilutive common share equivalents		—		—		334
Diluted weighted average number of shares outstanding		83,574		80,014		92,753

Segments Information

12 Months Ended

Dec. 31, 2019

Segment Reporting [Abstract]

Segments Information

21.	Segments Information

The Company operates in two reportable segments: Federal Solutions and Critical Infrastructure.

The Federal Solutions segment provides advanced technical solutions to the U.S. government, delivering timely, cost-effective hardware, software and services for mission-critical projects. The segment provides advanced technologies, supporting national security missions in cybersecurity, missile defense, and military facility modernization, logistics support, hazardous material remediation and engineering services.

The Critical Infrastructure segment provides integrated engineering and management services for complex physical and digital infrastructure around the globe. The Critical Infrastructure segment is a technology innovator focused on next generation digital systems and complex structures. Industry leading capabilities in engineering and project management allow the Company to deliver significant value to customers by employing cutting-edge technologies, improving timelines and reducing costs.

The Company defines its reportable segments based on the way the chief operating decision maker (“CODM”), currently its Chairman and Chief Executive Officer, evaluates the performance of each segment and manages the operations of the Company for purposes of allocating resources among the segments. The CODM evaluates segment operating performance using segment Revenue and segment Adjusted EBITDA attributable to Parsons Corporation.

The following table summarizes business segment information for the periods presented (in thousands):

	2017		2018		2019
Revenues:
Federal Solutions	$	1,079,906	$	1,479,007	$	1,887,907
Critical Infrastructure		1,937,105		2,081,501		2,066,905
Total revenues	$	3,017,011	$	3,560,508	$	3,954,812

The Company defines Adjusted EBITDA attributable to Parsons Corporation as Adjusted EBITDA excluding Adjusted EBITDA attributable to noncontrolling interests. The Company defines Adjusted EBITDA as net income (loss) attributable to Parsons Corporation, adjusted to include net income (loss) attributable to noncontrolling interests and to exclude interest expense (net of interest income), provision for income taxes, depreciation and amortization and certain other items that are not considered in the evaluation of ongoing operating performance. These other items include net income (loss) attributable to noncontrolling interests, asset impairment charges, income and expense recognized on litigation matters, expenses incurred in connection with acquisitions and other non-recurring transaction costs and expenses related to our prior restructuring. The following table summarizes business segment Adjusted EBITDA and a reconciliation to net income attributable to Parsons Corporation for the periods presented (in thousands):

	2017			2018			2019
Adjusted EBITDA attributable to Parsons Corporation
Federal Solutions	$	95,354		$	121,986		$	169,100
Critical Infrastructure		99,402			106,851			138,851
Adjusted EBITDA attributable to Parsons Corporation		194,756			228,837			307,951
Adjusted EBITDA attributable to noncontrolling interests		14,891			17,407			17,096
Depreciation and amortization		(35,198	)		(69,869	)		(125,700	)
Interest expense, net		(13,333	)		(18,132	)		(22,429	)
Income tax (expense) benefit		(21,464	)		(20,367	)		69,886
Litigation-related expenses (a)		(10,026	)		129,674			—
Amortization of deferred gain resulting from sale-leaseback transactions (b)		7,283			7,253			—
Equity-based compensation (c)		(19,016	)		(16,487	)		(65,744	)
Transaction-related costs (d)		(1,190	)		(12,942	)		(34,353	)
Restructuring (e)		—			—			(3,424	)
Other (f)		(5,166	)		(5,938	)		(6,155	)
Net income including noncontrolling interests	$	111,537		$	239,436		$	137,128
Net income attributable to noncontrolling interests		(14,211	)		(17,099	)		(16,594	)
Net income attributable to Parsons Corporation	$	97,326		$	222,337		$	120,534

(a)

Fiscal 2017 reflects post-judgment interest expense recorded in “(Interest and other expense) gain associated with claim on long-term contract” in our results of operations related to a judgment entered against the Company in 2014 in connection with a lawsuit against a joint venture in which the Company is the managing partner. Fiscal 2018 reflects a reversal of an accrued liability, with $55.1 million recorded to revenue and $74.6 million recorded to other income in our results of operations. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a description of this matter, which was resolved in favor of the Company on June 13, 2018.

(b)	Reflects recognized deferred gains related to sales-leaseback transactions described in “Note 10— Sale-Leasebacks.”

(c)	Reflects equity-based compensation costs primarily related to cash-settled awards. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a further discussion of these awards.

(c)	Reflects costs incurred in connection with acquisitions, IPO, and other non-recurring transaction costs, primarily fees paid for professional services and employee retention.

(d)	Reflects costs associated with and related to our corporate restructuring initiatives.

(e)	Includes a combination of gain/loss related to sale of fixed assets, software implementation costs, and other individually insignificant items that are non-recurring in nature.

Asset information by segment is not a key measure of performance used by the CODM.

The following table presents revenues and property and equipment, net by geographic area (in thousands):

	2017		2018		2019
Revenues:
North America	$	2,374,138	$	2,870,494	$	3,249,054
Middle East		621,796		671,925		689,067
Rest of World		21,077		18,089		16,691
Total revenues	$	3,017,011	$	3,560,508	$	3,954,812
Property and equipment, net
North America	$	80,852	$	86,847	$	117,606
Middle East		6,726		5,002		5,145
Total property and equipment, net	$	87,578	$	91,849	$	122,751

North America revenue includes $2.1 billion, $2.6 billion and $3.0 billion of United States revenue for the years ended December 29, 2017, December 31, 2018 and December 31, 2019, respectively. North America property and equipment, net includes $76.2 million, $79.9 million and $109.9 million of property and equipment, net in the United States at December 29, 2017, December 31, 2018 and December 31, 2019, respectively.

The geographic location of revenue is determined by the location of the customer. The prior reporting of revenue by geographic location has been conformed to the current presentation.

The following table presents revenues by business lines (in thousands):

	2017		2018		2019
Revenues:
Federal Solutions
Cyber & Intelligence	$	184,771	$	255,447	$	351,828
Defense		291,358		431,059		577,109
Mission Solutions		291,933		360,969		317,802
Engineered Systems		311,844		431,532		497,793
Geospatial		—		—		143,375
Federal Solutions revenues		1,079,906		1,479,007		1,887,907

Critical Infrastructure
Connected Communities		602,975		656,513		619,220
Mobility Solutions		1,102,725		1,183,863		1,120,563
Industrial		231,405		241,125		327,122
Critical Infrastructure revenues		1,937,105		2,081,501		2,066,905

Total revenues	$	3,017,011	$	3,560,508	$	3,954,812

Revenue for the year ended December 28, 2018 included $55.1 million related to the settlement of a claim that was resolved in favor of the Company in the Mobility Solutions business line of our Critical Infrastructure segment. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a description of this matter, which was resolved in favor of the Company on June 13, 2018. Excluding the claim settlement, revenue for the year ended December 31, 2018 for the Critical Infrastructure segment was $2.0 billion and for the Mobility Solutions revenue business line revenue was $1.1 billion.

Quarterly Information - Unaudited

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Information - Unaudited

22.	Quarterly Information - Unaudited

The following tables present selected quarterly financial information (in thousands except per share data).

	Fiscal Quarter Ended
	March 30, 2018		June 29, 2018(1)		September 28, 2018		December 31, 2018		March 31, 2019		June 30, 2019			September 30, 2019		December 31, 2019
Federal Solutions revenue	$	291,335	$	341,065	$	443,725	$	402,882	$	422,812	$	478,497		$	486,175	$	500,423
Critical Infrastructure revenue		463,344		559,667		532,432		526,058		481,593		511,245			537,102		536,965
Total revenue		754,679		900,732		976,157		928,940		904,405		989,742			1,023,277		1,037,388
Operating income		38,891		86,912		55,113		24,092		23,046		(8,706	)		53,449		24,274
Net income attributable to Parsons Corporation		25,287		148,381		41,222		7,447		9,741		40,259			56,812		13,722
Federal Solutions Adjusted EBITDA attributable to Parsons Corporation		21,549		33,947		45,556		20,934		40,599		35,700			50,359		42,442
Critical Infrastructure Adjusted EBITDA attributable to Parsons Corporation		25,361		16,929		38,006		26,555		27,676		40,525			33,976		36,674
Adjusted EBITDA attributable to noncontrolling interests		3,920		1,759		5,002		6,726		3,749		(20	)		4,655		8,712
Total Adjusted EBITDA (2)	$	50,830	$	52,635	$	88,564	$	54,215	$	72,024	$	76,205		$	88,990	$	87,828
Earnings per share:
Basic	$	0.31	$	1.83	$	0.52	$	0.10	$	0.12	$	0.44		$	0.57	$	0.14
Diluted	$	0.31	$	1.83	$	0.52	$	0.10	$	0.12	$	0.44		$	0.57	$	0.14

(1)

Includes reversal of an accrued liability, with $55.1 million recorded to revenue and 74.6 million recorded to other income in our results of operations related to a lawsuit against a joint venture in which the Company is the managing partner. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a description of this matter, which was resolved in favor of the Company on June 13, 2018.

(2)

The following table presents a reconciliation of net income attributable to Parsons Corporation to Adjusted EBITDA. For more information on our use of Adjusted EBITDA, how we use this metric, why we present this metric and the material limitations on usefulness of this metric, see “Note 21—Segments Information” in the “Other Information” table located in “Selected Consolidated Financial Data”.

	March 30, 2018			June 29, 2018			September 28, 2018			December 31, 2018			March 31, 2019		June 30, 2019			September 30, 2019			December 31, 2019
Net income attributable to Parsons Corporation	$	25,287		$	148,381		$	41,222		$	7,447		$	9,741	$	40,259		$	56,812		$	13,722
Interest expense, net		3,258			3,270			5,589			6,015			7,815		6,151			4,482			3,981
Income tax expense (benefit)		5,353			9,019			4,154			1,841			1,886		(53,496	)		(15,453	)		(2,823	)
Depreciation and amortization		9,009			14,048			23,599			23,213			30,591		31,074			31,027			33,008
Net income attributable to noncontrolling interests		3,815			1,657			4,844			6,783			3,645		(114	)		4,481			8,582
Litigation related expenses (a)		2,330			(132,004	)		-			-			-		-			-			-
Amortization of deferred gain resulting from sale-leaseback transactions (b)		(1,813	)		(1,829	)		(1,798	)		(1,813	)		-		-			-			-
Stock-based compensation (c)		3,100			5,049			5,049			3,289			3,850		43,311			(1,657	)		20,240
Transaction related costs (d)		125			4,930			2,456			5,431			9,355		7,715			9,891			7,392
Restructuring (e)		-			-			-			-			2,218		353			309			544
Other (f)		366			114			3,449			2,009			2,923		952			(902	)		3,182
Adjusted EBITDA	$	50,830		$	52,635		$	88,564		$	54,215		$	72,024	$	76,205		$	88,990		$	87,828

(a)

Fiscal 2017 reflect the post-judgment interest expense recorded in “(Interest and other expenses associated with claim on long-term contract” in our results of operations related to a lawsuit against a joint venture in which the Company is the managing partner. In fiscal 2018, the Company reversed the accrued liability with an offset of $55.1 million to revenue and $74.6 million to other income. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a description of this matter, which was resolved in favor of the Company on June 13, 2018

(b)	Reflects amortization of the deferred gain on prior sale-leaseback transactions in fiscal 2011. See “Note 10—Sale-Leasebacks” in the notes to our consolidated financial statements included elsewhere in this prospectus.

(c)	Reflects equity-based compensation costs primarily related to cash-settled awards. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a further discussion of these awards.

(d)	Reflects costs incurred in connection with acquisitions and other non-recurring transaction costs, including primarily fees paid for professional services and employee retention.

(e)	Reflects costs associated with and related to our corporate restructuring initiatives.

(f)	Includes a combination of gain/loss related to sale of fixed assets, software implementation costs, and other individually insignificant items that are non-recurring in nature.

Subsequent Events

12 Months Ended

Dec. 31, 2019

Subsequent Events [Abstract]

Subsequent Events

23.	Subsequent Events

None.

Schedule II—Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2019

Valuation And Qualifying Accounts [Abstract]

Schedule II—Valuation and Qualifying Accounts

PARSONS CORPORATION AND SUBSIDIARIES

Schedule II—Valuation and Qualifying Accounts

Description	Balance at beginning of period		Additions		Deductions			Other and foreign exchange impact			Balance at end of period
2017
Allowance for doubtful accounts		40,368		12,530		(2,730	)		2,743			52,911
Valuation allowance on deferred tax assets		7,444		3,456		(2,168	)		150			8,882
2018
Allowance for doubtful accounts		52,911		5,254		(6,085	)		(1,378	)		50,702
Valuation allowance on deferred tax assets		8,882		452		(2,633	)	-33				6,668
2019
Allowance for doubtful accounts		50,702		2,794		(10,661	)		(1,002	)		41,833
Valuation allowance on deferred tax assets		6,668		10,817		(32	)		(94	)		17,359

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Basis of Presentation and Principles of Consolidation

Identify the contract

Identify performance obligations

Determine the transaction price

Allocate the transaction price

Recognize revenue

The Company enters into the following types of contracts with its customers:

Cash Equivalents

Restricted Cash and Investments

Restricted cash and investments held in trust accounts represent collateral for certain incentive programs.

Accounts Receivable, Net

Accounts receivable includes billed and unbilled amounts and are recognized in the period when the Company’s rights to receive consideration are unconditional.

Contract Assets and Contract Liabilities

In connection with the adoption of ASC 606 on December 30, 2017, the Company revised its policy related to contract assets and contract liabilities.

Refer to the Recently Adopted Accounting Pronouncements for further discussion of the impact of adopting ASC 606.

Concentration of Credit Risk

In order to mitigate the credit risk associated with customers, the Company performs periodic credit evaluations of its customers’ financial condition.

Property and Equipment

Leases

Equity-Based Compensation

Business Combinations

Consolidation Of Joint Venture And Variable Interest Entity

Consolidation of Joint Ventures and Variable Interest Entities

Goodwill

The Company performs an additional review at year end to address the interim period.

Intangible Assets

Income Taxes

Foreign Currency Translation

Self-Insurance

Recently Adopted Accounting Pronouncements

The cumulative effect adjustment was an increase to accumulated deficit of $4.7 million as of December 30, 2017 as well as the following cumulative effect adjustments:

•

An increase to contract assets of $2.5 million;

•

An increase to deferred tax assets of $0.1 million;

•

An increase to contract liabilities of $7.2 million; and

•

An increase to non-controlling interests of $0.1 million.

Recently Issued Accounting Pronouncements

Acquisitions (Tables)

12 Months Ended

Dec. 31, 2019

Polaris Alpha

Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation

The following table summarizes the fair values of the assets acquired and liabilities assumed as of the date of acquisition (in thousands):

	Polaris Alpha
Cash and cash equivalents	$	7,914
Accounts receivable		29,688
Contract assets		35,229
Prepaid expenses and other current assets		9,295
Property and equipment		9,024
Goodwill		243,471
Intangible assets		199,520
Other noncurrent assets		2,203
Accounts payable		(13,942	)
Accrued expenses and other current liabilities		(26,419	)
Contract liabilities		(3,529	)
Deferred tax liabilities		(2,231	)
Other long-term liabilities		(1,146	)
Net assets acquired	$	489,077

Schedule of Intangible Assets Value on Purchase Price

Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years):

	Gross Carrying Amount		Amortization Period
			(in years)
Developed technology	$	84,900		4
Customer relationships		76,000		8
Backlog		34,900		2
Trade name		3,600		1
Leases		120		6

Schedule of Supplemental Pro Forma Information

Supplemental information on an unaudited pro forma basis, as if the acquisition closed as of the beginning of the fiscal year ended December 29, 2017 as follows (in thousands):

	2017		2018
	(unaudited)		(unaudited)
Pro forma Revenue	$	3,361,626	$	3,713,804
Pro forma Net Income including noncontrolling interest		58,356		225,861

OGSystems

Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation

The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on the purchase price allocation as of the date of acquisition (in thousands):

	Amount
Cash and cash equivalents	$	5,772
Accounts receivable		9,904
Contract assets		9,747
Prepaid expenses and other current assets		4,307
Property and equipment		4,085
Right of use assets, operating leases		8,826
Goodwill		183,540
Intangible assets		92,300
Other noncurrent assets		10
Accounts payable		(5,450	)
Accrued expenses and other current liabilities		(7,147	)
Contract liabilities		(1,300	)
Short-term lease liabilities, operating leases		(805	)
Income tax payable		(1,178	)
Deferred tax liabilities		(1,195	)
Long-term lease liabilities, operating leases		(8,021	)
Other long-term liabilities		(1,015	)
Net assets acquired	$	292,380

Schedule of Intangible Assets Value on Purchase Price

Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years):

	Gross Carrying Amount		Amortization Period
			(in years)
Customer relationships	$	57,100		5
Backlog		27,700		3
Trade name		3,800		2
Non-compete agreements		2,400		3
Developed technologies	$	1,300		3

Schedule of Supplemental Pro Forma Information

	2018		2019
	(unaudited)		(unaudited)
Pro forma Revenue	$	3,676,894	$	3,956,767
Pro forma Net Income including noncontrolling interests		205,961		134,046

QRC Technologies

Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation

	Amount
Cash and cash equivalents	$	5,925
Accounts receivable		5,587
Prepaid expenses and other current assets		5,727
Property and equipment		1,205
Right of use assets, operating leases		5,228
Goodwill		125,091
Intangible assets		76,200
Accounts payable		(1,567	)
Accrued expenses and other current liabilities		(4,025	)
Short-term lease liabilities, operating leases		(545	)
Long-term lease liabilities, operating leases		(4,683	)
Net assets acquired	$	214,143

Schedule of Intangible Assets Value on Purchase Price

Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years):

	Gross Carrying Amount		Amortization Period
			(in years)
Customer relationships	$	49,800		12
Developed technologies		21,800	3 to 5
In-process research and development		1,800	3 to 5
Non-compete agreements		1,200		4
Trade name		800		2
Backlog		800		1

Schedule of Supplemental Pro Forma Information

	2018		2019
	(unaudited)		(unaudited)
Pro forma Revenue	$	3,596,920	$	3,976,361
Pro forma Net Income		221,930		138,692

Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2019

Revenue From Contract With Customer [Abstract]

Summary of Disaggregation of Revenue

	December 31, 2018		December 31, 2019
Cost plus	$	1,473,815	$	1,705,832
Time-and-Materials		961,759		1,074,037
Fixed price		1,124,934		1,174,943
Total	$	3,560,508	$	3,954,812

Summary of Contract Assets and Contract Liabilities

Contract assets and contract liabilities balances at December 31, 2018 and December 31, 2019 were as follows (in thousands):

	December 31, 2018		December 31, 2019		$ change		% change
Contract assets	$	515,319	$	575,089	$	59,770		11.60	%
Contract liabilities		208,576		230,681		22,105		10.60	%
Net contract assets (liabilities)(1)	$	306,743	$	344,408	$	37,665		12.28	%

(1)

Schedule of Change in Contract Assets and Contract Liabilities

The change in contract assets and contract liabilities was the result of normal business activity and not significantly impacted by other factors, except as follows:

	December 31, 2018		December 31, 2019
Acquired contract assets	$	35,229	$	9,747
Acquired contract liabilities		3,529		1,300
Change in the estimate of variable consideration		—		12,166
Reversal of provision for contract losses(1)	$	133,180	$	—

(1)	Reversal of provision for contract losses of $133.2 million, of which $55.1 million was recorded as an increase in revenue with the remainder recorded as other income.

Summary of Accounts Receivable, Net

Accounts receivable, net consisted of the following as of December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019
Billed	$	538,808		$	494,366
Unbilled		135,180			218,959
Total accounts receivable, gross		673,988			713,325
Allowance for doubtful accounts		(50,702	)		(41,833	)
Total accounts receivable, net	$	623,286		$	671,492

Summary of Remaining Unsatisfied Performance Obligations Expect to Satisfy

The Company expects to satisfy its RUPO as of December 31, 2019 over the following periods (in thousands):

	Within One Year		Within One to Two Years		Thereafter
Federal Solutions	$	1,207,900	$	451,278	$	176,103
Critical Infrastructure		1,634,625		632,273		859,966
Total RUPO	$	2,842,525	$	1,083,551	$	1,036,069

Leases (Tables)

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

Summary of Lease Costs

The components of lease costs for the year ended December 31, 2019 are as follows (in thousands):

	2019
Operating lease cost	$	70,112
Short-term lease cost		11,988
Amortization of right-of-use assets		746
Interest on lease liabilities		77
Sublease income		(3,620	)
Total lease cost	$	79,303

Schedule of Supplemental Cash Flow Information Related to Leases

Supplemental cash flow information related to leases for the year ended December 31, 2019 is as follows (in thousands):

	2019
Operating cash flows for operating leases	$	62,714
Operating cash flows for financing activities		77
Financing cash flows from finance leases		863
Right-of-use assets obtained in exchange for new operating lease liabilities		299,503
Right-of-use assets obtained in exchange for new finance lease liabilities	$	3,124

Schedule of Supplemental Balance Sheet and Other Information Related to Leases

Supplemental balance sheet and other information related to leases as of December 31, 2019 is as follows (in thousands):

	2019
Operating Leases:
Right-of-use assets	$	233,415
Lease liabilities:
Current	$	49,994
Long-term		203,624
Total operating lease liabilities	$	253,618
Finance Leases:
Other noncurrent assets	$	2,377
Accrued expenses and other current liabilities	$	1,075
Other long-term liabilities	$	1,202

Weighted Average Remaining Lease Term:
Operating leases	6 years
Finance leases	3 years
Weighted Average Discount Rate:
Operating leases		4.0	%
Finance leases		4.5	%

Schedule of Maturity Analysis of Future Undiscounted Cash Flows

A maturity analysis of the future undiscounted cash flows associated with the Company’s operating and finance lease liabilities as of December 31, 2019 is as follows (in thousands):

	Operating Leases			Finance Leases
2020	$	58,412		$	1,152
2021		54,491			870
2022		48,454			326
2023		41,424			48
2024		30,945			—
Thereafter		49,727			—
Total lease payments		283,453			2,396
Less: imputed interest		(29,835	)		(119	)
Total present value of lease liabilities	$	253,618		$	2,277

Equity-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Summary of Assumptions Used in Black-Scholes Options Pricing Model

The following table presents the assumptions used in the Black-Scholes option-pricing model for SARs outstanding at the year-end measurement date:

	December 31, 2019
Dividend yield		0.0	%
Expected volatility		31.0	%
Risk-free interest rate		1.6	%
Expected term		1.0

Schedule of Amount Paid for Cash Settled Awards by Award Type

The following table presents the amount paid for cash settled awards, by award type, for the years ended December 29, 2017, December 31, 2018, and December 31, 2019 (in thousands):

	December 29, 2017		December 31, 2018		December 31, 2019
Stock Appreciation Rights	$	170	$	4,576	$	5,261
Long-Term Growth		8,246		1,095		1,108
Restricted Award Units		2,635		4,439		5,537
Total	$	11,051	$	10,110	$	11,906

Summary of Restricted Stock Outstanding

For the year ended December 31, 2019, 74,704 shares of restricted stock units were issued, and 27,962 shares of common stock related to employee statutory income tax withholding were retired.

The following table presents the number of shares of restricted stock outstanding (at target shares for awards with performance conditions) at December 31, 2019:

December 31,

2019

Weighted Average Grant-Date Fair Value

Restricted Stock Units (service condition)

189,090

34.15

Restricted Stock Units (service and performance condition)

317,550

34.02

Stock Appreciation Rights

Summary of Stock Appreciation Right Activity

The following table presents the number of SARs granted, vested, and forfeited for the years ended December 29, 2017, December 31, 2018, and December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at December 30, 2016		3,170,565		$	3.00
Granted		2,096,439		$	3.00
Vested		(1,573,998	)	$	3.00
Forfeited		(297,631	)	$	3.00
Unvested at December 29, 2017		3,395,375		$	3.00
Granted		1,708,746		$	3.00
Vested		(1,322,805	)	$	3.00
Forfeited		(364,662	)	$	3.00
Unvested at December 31, 2018		3,416,654		$	3.00
Granted		—		$	—
Vested		(1,547,142	)	$	3.00
Forfeited		(391,884	)	$	3.00
Unvested at December 31, 2019		1,477,628		$	3.00

Long-Term Growth Units

Schedule of Unvested Share Activity

The following table presents the number of Long-Term Growth Units granted, vested, and forfeited (at target shares) for the years ended December 29, 2017, December 31, 2018, and December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at December 30, 2016		331,986		$	19.65
Granted		174,270		$	20.33
Vested		(176,781	)	$	19.33
Forfeited		(21,594	)	$	20.09
Unvested at December 29, 2017		307,881		$	20.18
Granted		144,777		$	22.67
Vested		(136,221	)	$	20.00
Forfeited		(16,656	)	$	20.27
Unvested at December 31, 2018		299,781		$	20.23
Granted		—		$	—
Vested		(137,760	)	$	20.33
Forfeited		(34,584	)	$	21.50
Unvested at December 31, 2019		127,437		$	21.45

Restricted Award Units

Summary of Restricted Stock Unit Activity

The following table presents the number of Restricted Award Units granted, vested, and forfeited for the years ended December 29, 2017, December 31, 2018, and December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at December 30, 2016		534,355		$	19.85
Granted		306,843		$	20.33
Vested		(135,982	)	$	19.53
Forfeited		(45,771	)	$	19.90
Unvested at December 29, 2017		659,445		$	20.14
Granted		262,140		$	22.67
Vested		(264,408	)	$	20.00
Forfeited		(67,827	)	$	20.34
Unvested at December 31, 2018		589,350		$	21.31
Granted		—		$	—
Vested		(281,805	)	$	20.33
Forfeited		(58,101	)	$	21.31
Unvested at December 31, 2019		249,444		$	22.40

Restricted Stock Units

Summary of Restricted Stock Unit Activity

The following table presents the number and weighted average grant-date fair value of restricted stock units (at target shares for awards with performance conditions) at December 31, 2019:

	Number of Units			Weighted Average Grant-Date Fair Value
Outstanding at December 31, 2018		-		$	-
Granted		598,219			34.06
Vested		(74,704	)		34.02
Forfeited		(16,875	)		34.02
Outstanding at December 31, 2019		506,640		$	34.07

Summary of Restricted Stock Outstanding

The following table presents the number of shares of restricted stock units granted (at target shares for awards with performance conditions) for the year ended December 31, 2019:

December 31,

2019

Weighted Average Grant-Date Fair Value

Restricted Stock Units (service condition)

270,544

34.11

Restricted Stock Units (service and performance condition)

327,675

34.02

Goodwill (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Changes in Carrying Value of Goodwill by Reporting Segment

The following table summarizes the changes in the carrying value of goodwill by reporting segment for fiscal years ended December 31, 2018 and December 31, 2019 (in thousands):

	December 29, 2017		Acquisitions		Foreign Exchange			December 31, 2018
Federal Solutions	$	422,439	$	244,402	$	—		$	666,841
Critical Infrastructure		74,347		—		(4,250	)		70,097
Total	$	496,786	$	244,402	$	(4,250	)	$	736,938

	December 31 , 2018		Acquisitions		Foreign Exchange		December 31, 2019
Federal Solutions	$	666,841	$	308,564	$	—	$	975,405
Critical Infrastructure		70,097		—		1,923		72,020
Total	$	736,938	$	308,564	$	1,923	$	1,047,425

Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Schedule of Gross Amount and Accumulated Amortization of Intangible Assets

	December 31, 2018							December 31, 2019
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted Average Amortization Period (in years)
Backlog	$	80,754	$	(58,295	)	$	22,459	$	109,255	$	(87,510	)	$	21,745		3
Customer relationships		121,629		(38,974	)		82,655		228,529		(67,809	)		160,720		7
Leases		670		(561	)		109		670		(580	)		90		5
Developed technology		87,839		(15,174	)		72,665		110,939		(40,749	)		70,190		4
Trade name		3,600		(2,100	)		1,500		8,200		(5,667	)		2,533		1
Non-compete agreements		—		—			—		3,600		(925	)		2,675		3
In process research and development		—		—			—		1,800		—			1,800	n/a
Other intangibles		—		—			—		275		(170	)		105		10
Total intangible assets	$	294,492	$	(115,104	)	$	179,388	$	463,268	$	(203,410	)	$	259,858

Schedule of Estimated Amortization Expense

Estimated amortization expense in each of the next five years and beyond is as follows (in thousands):

2020	$	86,574
2021		81,591
2022		36,100
2023		23,549
2024		9,098
Thereafter		21,146
	$	258,058

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2019

Property Plant And Equipment [Abstract]

Schedule of Property and equipment, net

Property and equipment consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019			Useful lives (years)
Building and leasehold improvements	$	54,348		$	81,065		1-15
Furniture and equipment		81,705			91,720		3-10
Computer systems and equipment		148,255			164,161		3-10
Construction equipment		12,074			11,765		5-7
		296,382			348,711
Less: Accumulated depreciation		(204,533	)		(225,960	)
Property and equipment, net	$	91,849		$	122,751

Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2019

Payables And Accruals [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018		2019
Salaries and wages	$	50,991	$	46,685
Employee benefits		214,008		259,081
Self-insurance liability		29,682		29,997
Project cost accruals		183,362		217,729
Other accrued expenses		81,657		86,371
Total accrued expenses and other current liabilities	$	559,700	$	639,863

Debt and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Schedule of Long Term Debt

Long-term debt consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019
Revolving credit facility	$	180,000		$	—
Senior notes		250,000			250,000
Debt issuance costs		(836	)		(647	)
Long-term debt	$	429,164		$	249,353

Schedule of Aggregate Amount Debt Repayable

On July 1, 2014, the Company finalized a private placement whereby the Company raised an aggregate amount of $250.0 million in debt repayable as follows (in thousands):

Tranche	Debt Amount		Maturity Date	Interest Rate
Senior Note, Series A	$	50,000	July 15, 2021		4.44	%
Senior Note, Series B		100,000	July 15, 2024		4.98	%
Senior Note, Series C		60,000	July 15, 2026		5.13	%
Senior Note, Series D		40,000	July 15, 2029		5.38	%

Other Long-term Liabilities (Tables)

12 Months Ended

Dec. 31, 2019

Other Liabilities Disclosure [Abstract]

Schedule of Other Long-term Liabilities

Other long-term liabilities consisted of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018		2019
Self-insurance liability	$	99,813	$	102,521
Deferred rent		15,966		—
Reserve for uncertain tax positions		9,890		14,427
Finance lease obligations		935		1,202
Other long-term liabilities		1,259		7,554
Total other long-term liabilities	$	127,863	$	125,704

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Components of Income from Continuing Operations Before Income Taxes

The following table presents the components of our income from continuing operations before income taxes (in thousands):

	2017		2018		2019
United States earnings	$	85,913	$	205,418	$	6,762
Foreign earnings		47,088		54,385		60,480
	$	133,001	$	259,803	$	67,242

Schedule of Income Tax Expense (Benefit) Attributable to Income from Continuing Operations

	2017			2018			2019
Current
Federal	$	-		$	-		$	22,865
State		1,579			1,536		$	10,428
Foreign		14,482			20,253			20,159
Total current income tax expense		16,061			21,789			53,452
Deferred
Federal		—			—			(97,299	)
State		(569	)		2,329			(27,432	)
Foreign		5,972			(3,751	)		1,393
Total deferred tax expense (benefit)		5,403			(1,422	)		(123,338	)
Total income tax expense (benefit)	$	21,464		$	20,367		$	(69,886	)

Computation of Income Tax Expense (Benefit)

	2017					2018					2019
Income before income tax expense (benefit)	$	133,001				$	259,803				$	67,242
Tax at federal statutory tax rate		46,550		35	%		54,559		21	%		14,121		21	%
S- corporation exclusion		(25,109	)	(19	)%		(39,539	)	(15	)%		(4,875	)	(7	)%
State taxes, net of federal tax benefit		1,010		1	%		3,865		1	%		3,223		5	%
Change in tax status		—		—			—		—			(93,878	)	(140	)%
Change in valuation allowance		1,438		1	%		(2,215	)	(1	)%		4,502		7	%
Change in uncertain tax positions		(34	)	0	%		629		0	%		4,118		6	%
Foreign tax rate differential		(907	)	(1	)%		4,168		2	%		4,886		7	%
Foreign tax credits		—		—			—		—			(1,313	)	(2	)%
Transaction costs		—		—			—		—			1,052		1	%
Other permanent items, net		—		—			—		—			1,182		2	%
Noncontrolling interests		(4,960	)	(4	)%		(3,599	)	(1	)%		(2,282	)	(3	)%
Other, net		3,476		3	%		2,499		1	%		(622	)	(1	)%
Total income tax expense (benefit)	$	21,464		16	%	$	20,367		8	%	$	(69,886	)	(104	)%

Components of Deferred Tax Assets and Liabilities

The components of deferred tax assets and liabilities consists of the following at December 31, 2018 and December 31, 2019 (in thousands):

	2018			2019
Deferred tax assets
Project and non-project reserves	$	2,326		$	34,225
Employee compensation and benefits		1,609			59,624
Revenue and cost recognition		—			33,588
Insurance accruals		962			19,204
Net operating losses		14,855			16,400
Lease liabilities		205			68,447
Tax credit carryforwards		377			8,969
Other		2,240			3,318
Valuation allowance		(6,668	)		(17,358	)
Total deferred tax assets		15,906			226,417
Deferred tax liabilities
Intangible assets		(2,529	)		(29,543	)
Right of use assets		—			(63,032	)
Revenue and cost recognition		(10,570	)		—
Other		(3,367	)		(13,063	)
Total deferred tax liabilities		(16,466	)		(105,638	)
Net deferred tax (liability) asset	$	(560	)	$	120,779

Reconciliation of Beginning and Ending Balances of Unrecognized Tax Benefits

A reconciliation of the beginning and ending balances of unrecognized tax benefits is as follows (in thousands):

	2017			2018			2019
Beginning of year	$	7,827		$	7,137		$	7,845
Increases—current year tax positions		1,134			1,094			7,531
Increases—prior year tax positions		319			1,301			1,379
Decreases—prior year tax positions		(1,629	)		(1,656	)		(991	)
Settlements		(361	)		—			(124	)
Lapse of statute of limitations		(153	)		(31	)		(114	)
End of year	$	7,137		$	7,845		$	15,526

Investments in and Advances to Joint Ventures (Tables)

12 Months Ended

Dec. 31, 2019

Equity Method Investments And Joint Ventures [Abstract]

Schedule of Financial Information of Consolidated Joint Ventures

	2018		2019
Current assets	$	287,227	$	255,167
Noncurrent assets		2,689		2,860
Total assets		289,916		258,027
Current liabilities		199,833		193,583
Total liabilities		199,833		193,583
Total joint venture equity	$	90,083	$	64,444

	2017		2018		2019
Revenue	$	446,506	$	540,345	$	473,486
Costs		426,245		376,628		435,947
Net income	$	20,261	$	163,717	$	37,539
Net income attributable to noncontrolling interests	$	14,211	$	17,099	$	16,594

Summary of Financial Information for Unconsolidated Joint Ventures

	2018		2019
Current assets	$	707,457	$	801,335
Noncurrent assets		876,385		564,160
Total assets		1,583,842		1,365,495
Current liabilities		560,306		655,495
Noncurrent liabilities		813,269		507,131
Total liabilities		1,373,575		1,162,626
Total joint venture equity	$	210,267	$	202,869
Investments in and advances to unconsolidated joint ventures	$	63,560	$	68,620

	2017		2018		2019
Revenue	$	2,114,903	$	1,773,037		2,081,341
Costs		1,988,569		1,661,232		1,903,582
Net income	$	126,334	$	111,805		177,759
Equity in earnings of unconsolidated joint ventures	$	40,086	$	36,915		41,721

Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2019

Schedule of Consolidated Balance Sheet Related to Services Provided to Unconsolidated Joint Ventures

Amounts included in the consolidated balance sheets related to services the Company provided to unconsolidated joint ventures is as follows (in thousands):

	2018		2019
Accounts receivable	$	38,742		37,425
Contract assets		2,648		6,955
Contract liabilities	$	10,861		4,509

Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Summary of Fair Value Assets Associated with Pension Plan

Fair value as of December 31, 2018 (in thousands):

	Level 1		Level 2		Level 3		Total
Mutual funds	$	2,539	$	—	$	—	$	2,539
Fixed income		—		10,168		—		10,168
Cash and cash equivalents		361		—		—		361
	$	2,900	$	10,168	$	—	$	13,068

Fair value as of December 31, 2019 (in thousands):

	Level 1		Level 2		Level 3		Total
Mutual funds		2,987		—		—		2,987
Fixed income		—		10,447		—		10,447
Cash and cash equivalents		334		—		—		334
		3,321		10,447		—		13,768

Schedule of Fair Value of Redeemable Common Stock Associated Employee Stock Ownership Plan

Fair value as of December 31, 2018 (in thousands):

	Level 1		Level 2		Level 3		Total
Redeemable Common Stock	$	—	$	—	$	1,876,309	$	1,876,309
	$	—	$	—	$	1,876,309	$	1,876,309

Schedule of Reconciliation Fair Value Measurements Using Significant Unobservable Inputs

The following table presents a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3) (in thousands):

	2018			2019
Balance at beginning of year	$	1,855,305			1,876,309
Purchases of treasury stock		(125,814	)		(6,219	)
Contributions of treasury stock to ESOP		47,043			—
Share price adjustment		99,775			883,436
Transfer to permanent equity		—			(2,753,526	)
Balance at end of year	$	1,876,309			—

Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Schedule of Weighted Average Number of Shares Used To Compute Basic and Diluted EPS

The weighted average number of shares used to compute basic and diluted EPS were (in thousands):

	2017		2018		2019
Basic weighted average number of shares outstanding		83,574		80,014		92,419
Dilutive common share equivalents		—		—		334
Diluted weighted average number of shares outstanding		83,574		80,014		92,753

Segments Information (Tables)

12 Months Ended

Dec. 31, 2019

Segment Reporting [Abstract]

Summary of Business Segment Information

The following table summarizes business segment information for the periods presented (in thousands):

	2017		2018		2019
Revenues:
Federal Solutions	$	1,079,906	$	1,479,007	$	1,887,907
Critical Infrastructure		1,937,105		2,081,501		2,066,905
Total revenues	$	3,017,011	$	3,560,508	$	3,954,812

Summary of Adjusted EBITDA Business Segment Information

The following table summarizes business segment Adjusted EBITDA and a reconciliation to net income attributable to Parsons Corporation for the periods presented (in thousands):

	2017			2018			2019
Adjusted EBITDA attributable to Parsons Corporation
Federal Solutions	$	95,354		$	121,986		$	169,100
Critical Infrastructure		99,402			106,851			138,851
Adjusted EBITDA attributable to Parsons Corporation		194,756			228,837			307,951
Adjusted EBITDA attributable to noncontrolling interests		14,891			17,407			17,096
Depreciation and amortization		(35,198	)		(69,869	)		(125,700	)
Interest expense, net		(13,333	)		(18,132	)		(22,429	)
Income tax (expense) benefit		(21,464	)		(20,367	)		69,886
Litigation-related expenses (a)		(10,026	)		129,674			—
Amortization of deferred gain resulting from sale-leaseback transactions (b)		7,283			7,253			—
Equity-based compensation (c)		(19,016	)		(16,487	)		(65,744	)
Transaction-related costs (d)		(1,190	)		(12,942	)		(34,353	)
Restructuring (e)		—			—			(3,424	)
Other (f)		(5,166	)		(5,938	)		(6,155	)
Net income including noncontrolling interests	$	111,537		$	239,436		$	137,128
Net income attributable to noncontrolling interests		(14,211	)		(17,099	)		(16,594	)
Net income attributable to Parsons Corporation	$	97,326		$	222,337		$	120,534

(a)

(b)	Reflects recognized deferred gains related to sales-leaseback transactions described in “Note 10— Sale-Leasebacks.”

(c)	Reflects equity-based compensation costs primarily related to cash-settled awards. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a further discussion of these awards.

(c)	Reflects costs incurred in connection with acquisitions, IPO, and other non-recurring transaction costs, primarily fees paid for professional services and employee retention.

(d)	Reflects costs associated with and related to our corporate restructuring initiatives.

(e)	Includes a combination of gain/loss related to sale of fixed assets, software implementation costs, and other individually insignificant items that are non-recurring in nature.

Summary of Revenues and Property and Equipment, Net by Geographic Area

The following table presents revenues and property and equipment, net by geographic area (in thousands):

	2017		2018		2019
Revenues:
North America	$	2,374,138	$	2,870,494	$	3,249,054
Middle East		621,796		671,925		689,067
Rest of World		21,077		18,089		16,691
Total revenues	$	3,017,011	$	3,560,508	$	3,954,812
Property and equipment, net
North America	$	80,852	$	86,847	$	117,606
Middle East		6,726		5,002		5,145
Total property and equipment, net	$	87,578	$	91,849	$	122,751

Summary of Revenues by Business Lines

The following table presents revenues by business lines (in thousands):

	2017		2018		2019
Revenues:
Federal Solutions
Cyber & Intelligence	$	184,771	$	255,447	$	351,828
Defense		291,358		431,059		577,109
Mission Solutions		291,933		360,969		317,802
Engineered Systems		311,844		431,532		497,793
Geospatial		—		—		143,375
Federal Solutions revenues		1,079,906		1,479,007		1,887,907

Critical Infrastructure
Connected Communities		602,975		656,513		619,220
Mobility Solutions		1,102,725		1,183,863		1,120,563
Industrial		231,405		241,125		327,122
Critical Infrastructure revenues		1,937,105		2,081,501		2,066,905

Total revenues	$	3,017,011	$	3,560,508	$	3,954,812

Quarterly Information - Unaudited (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Schedule of Selected Quarterly Financial Information

The following tables present selected quarterly financial information (in thousands except per share data).

	Fiscal Quarter Ended
	March 30, 2018		June 29, 2018(1)		September 28, 2018		December 31, 2018		March 31, 2019		June 30, 2019			September 30, 2019		December 31, 2019
Federal Solutions revenue	$	291,335	$	341,065	$	443,725	$	402,882	$	422,812	$	478,497		$	486,175	$	500,423
Critical Infrastructure revenue		463,344		559,667		532,432		526,058		481,593		511,245			537,102		536,965
Total revenue		754,679		900,732		976,157		928,940		904,405		989,742			1,023,277		1,037,388
Operating income		38,891		86,912		55,113		24,092		23,046		(8,706	)		53,449		24,274
Net income attributable to Parsons Corporation		25,287		148,381		41,222		7,447		9,741		40,259			56,812		13,722
Federal Solutions Adjusted EBITDA attributable to Parsons Corporation		21,549		33,947		45,556		20,934		40,599		35,700			50,359		42,442
Critical Infrastructure Adjusted EBITDA attributable to Parsons Corporation		25,361		16,929		38,006		26,555		27,676		40,525			33,976		36,674
Adjusted EBITDA attributable to noncontrolling interests		3,920		1,759		5,002		6,726		3,749		(20	)		4,655		8,712
Total Adjusted EBITDA (2)	$	50,830	$	52,635	$	88,564	$	54,215	$	72,024	$	76,205		$	88,990	$	87,828
Earnings per share:
Basic	$	0.31	$	1.83	$	0.52	$	0.10	$	0.12	$	0.44		$	0.57	$	0.14
Diluted	$	0.31	$	1.83	$	0.52	$	0.10	$	0.12	$	0.44		$	0.57	$	0.14

(1)

(2)

	March 30, 2018			June 29, 2018			September 28, 2018			December 31, 2018			March 31, 2019		June 30, 2019			September 30, 2019			December 31, 2019
Net income attributable to Parsons Corporation	$	25,287		$	148,381		$	41,222		$	7,447		$	9,741	$	40,259		$	56,812		$	13,722
Interest expense, net		3,258			3,270			5,589			6,015			7,815		6,151			4,482			3,981
Income tax expense (benefit)		5,353			9,019			4,154			1,841			1,886		(53,496	)		(15,453	)		(2,823	)
Depreciation and amortization		9,009			14,048			23,599			23,213			30,591		31,074			31,027			33,008
Net income attributable to noncontrolling interests		3,815			1,657			4,844			6,783			3,645		(114	)		4,481			8,582
Litigation related expenses (a)		2,330			(132,004	)		-			-			-		-			-			-
Amortization of deferred gain resulting from sale-leaseback transactions (b)		(1,813	)		(1,829	)		(1,798	)		(1,813	)		-		-			-			-
Stock-based compensation (c)		3,100			5,049			5,049			3,289			3,850		43,311			(1,657	)		20,240
Transaction related costs (d)		125			4,930			2,456			5,431			9,355		7,715			9,891			7,392
Restructuring (e)		-			-			-			-			2,218		353			309			544
Other (f)		366			114			3,449			2,009			2,923		952			(902	)		3,182
Adjusted EBITDA	$	50,830		$	52,635		$	88,564		$	54,215		$	72,024	$	76,205		$	88,990		$	87,828

(a)

(b)	Reflects amortization of the deferred gain on prior sale-leaseback transactions in fiscal 2011. See “Note 10—Sale-Leasebacks” in the notes to our consolidated financial statements included elsewhere in this prospectus.

(c)	Reflects equity-based compensation costs primarily related to cash-settled awards. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this Annual Report on Form 10-K for a further discussion of these awards.

(d)	Reflects costs incurred in connection with acquisitions and other non-recurring transaction costs, including primarily fees paid for professional services and employee retention.

(e)	Reflects costs associated with and related to our corporate restructuring initiatives.

(f)	Includes a combination of gain/loss related to sale of fixed assets, software implementation costs, and other individually insignificant items that are non-recurring in nature.

Description of Operations - Additional Information (Details) - USD ($)					12 Months Ended
	May 31, 2019	May 14, 2019	May 08, 2019	Apr. 15, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Description Of Operations Disclosure [Line Items]
Proceeds from IPO					$ 536,879,000	$ 0	$ 0
Funds to dividend through public offering		$ 52,100,000
Repayment on term loan through public offering		$ 150,000
Common stock dividend ratio				200.00%
Dividends declared date				Apr. 15, 2019
Dividends payment, date				May 08, 2019
Dividends record date				May 07, 2019
IPO \| Common Stock
Description Of Operations Disclosure [Line Items]
Common stock shares sold			18,518,500
Common stock sold per share			$ 27.00
Share price		$ 25.515
Proceeds from IPO		$ 536,900,000
Underwriters \| Common Stock
Description Of Operations Disclosure [Line Items]
Purchase of additional shares upon exercise of options	2,777,775
Underwriting discount per share		$ 1.485
Proceeds from IPO		$ 536,900,000

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) Customer shares	Dec. 31, 2018 USD ($) shares	Dec. 29, 2017 USD ($) shares	Dec. 30, 2017 USD ($)
Significant Accounting Policies [Line Items]
Contributions to ESOP \| shares		1,345,198	1,874,988	1,790,496
Repurchase of shares of common stock from ESOP \| shares		191,331	5,553,891	5,843,211
Redemption value of ESOP participants interest		$ 6,300	$ 125,800	$ 111,400
Increase in retained earnings		(218,025)	12,445
ASC 606
Significant Accounting Policies [Line Items]
Adoption of ASC 606			$ (4,735)
ASC 606 \| Difference between Revenue Guidance in Effect before and after Topic 606
Significant Accounting Policies [Line Items]
Increase in retained earnings					$ 4,700
ASC 606 \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Increase to Contract Assets
Significant Accounting Policies [Line Items]
Cumulative effect adjustments					2,500
ASC 606 \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Increase to Deferred Tax Assets
Significant Accounting Policies [Line Items]
Cumulative effect adjustments					100
ASC 606 \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Increase to Contract Liabilities
Significant Accounting Policies [Line Items]
Cumulative effect adjustments					7,200
ASC 606 \| Difference between Revenue Guidance in Effect before and after Topic 606 \| Increase to Non-controlling Interests
Significant Accounting Policies [Line Items]
Cumulative effect adjustments					$ 100
Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Adoption of ASC 606		52,608
Accounting Standards Update 2016-02 \| Net Deferred Tax Asset
Significant Accounting Policies [Line Items]
Adoption of ASC 606		52,600
Accounting Standards Update 2016-02 \| Deferred Tax Asset
Significant Accounting Policies [Line Items]
Adoption of ASC 606	$ 700	$ 700
Concentration of Credit Risk
Significant Accounting Policies [Line Items]
Number of customers representing more than 10% of revenue \| Customer		0
Number of customers representing more than 10% of accounts receivable \| Customer		0
Revenue Benchmark \| Concentration of Credit Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage		48.00%	42.00%	36.00%
Accounts Receivable \| Concentration of Credit Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage		18.00%	29.00%
Minimum
Significant Accounting Policies [Line Items]
Performance obligations payment terms from date of invoice		30 days
Intangible assets useful lives of underlying assets		1 year
Maximum
Significant Accounting Policies [Line Items]
Performance obligations payment terms from date of invoice		120 days
Intangible assets useful lives of underlying assets		10 years

Acquisitions - Additional Information (Details) - USD ($) $ in Thousands					3 Months Ended								12 Months Ended
	Jul. 31, 2019	Jan. 07, 2019	May 31, 2018	Oct. 06, 2017	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Business Acquisition [Line Items]
Cash received													$ 494,826	$ 481,163	$ 25,737
Amortization of intangible assets													88,300	37,400	5,600
Goodwill					$ 1,047,425				$ 736,938				1,047,425	736,938	496,786
Revenues					1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	3,954,812	3,560,508	$ 3,017,011
Williams Electric Company, Inc.
Business Acquisition [Line Items]
Cash received				$ 25,700
Polaris Alpha
Business Acquisition [Line Items]
Percentage of ownership interest acquired			100.00%
Cash paid to acquire			$ 489,100
Borrowed under credit agreement to partially fund the acquisition			260,000
Amortization of intangible assets													54,500	30,300
Goodwill			$ 243,471
Goodwill deductible for tax purposes					$ 50,100								50,100
Revenues														227,300
Polaris Alpha \| Indirect, General and Administrative Expense
Business Acquisition [Line Items]
Acquisition related expenses														$ 6,200
OGSystems
Business Acquisition [Line Items]
Percentage of ownership interest acquired		100.00%
Cash paid to acquire		$ 292,400
Borrowed under credit agreement to partially fund the acquisition		110,000
Amortization of intangible assets													23,800
Goodwill		183,540
Goodwill deductible for tax purposes		16,000
Revenues													143,400
OGSystems \| Term Loan
Business Acquisition [Line Items]
Borrowed under credit agreement to partially fund the acquisition		$ 150,000
OGSystems \| Indirect, General and Administrative Expense
Business Acquisition [Line Items]
Acquisition related expenses													5,400
QRC Technologies
Business Acquisition [Line Items]
Percentage of ownership interest acquired	100.00%
Cash paid to acquire	$ 214,100
Amortization of intangible assets													5,700
Goodwill	125,091
Revenues													$ 11,200
QRC Technologies \| Revolving Credit Facility
Business Acquisition [Line Items]
Borrowed under credit agreement to partially fund the acquisition	140,000
QRC Technologies \| Indirect, General and Administrative Expense
Business Acquisition [Line Items]
Acquisition related expenses	$ 4,900

Acquisitions - Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jul. 31, 2019	Jan. 07, 2019	Dec. 31, 2018	May 31, 2018	Dec. 29, 2017
Business Acquisition [Line Items]
Contract assets	$ 575,089			$ 515,319
Goodwill	1,047,425			736,938		$ 496,786
Contract liabilities	$ (230,681)			$ (208,576)
Polaris Alpha
Business Acquisition [Line Items]
Cash and cash equivalents					$ 7,914
Accounts receivable					29,688
Contract assets					35,229
Prepaid expenses and other current assets					9,295
Property and equipment					9,024
Goodwill					243,471
Intangible assets					199,520
Other noncurrent assets					2,203
Accounts payable					(13,942)
Accrued expenses and other current liabilities					(26,419)
Contract liabilities					(3,529)
Deferred tax liabilities					(2,231)
Other long-term liabilities					(1,146)
Net assets acquired					$ 489,077
OGSystems
Business Acquisition [Line Items]
Cash and cash equivalents			$ 5,772
Accounts receivable			9,904
Contract assets			9,747
Prepaid expenses and other current assets			4,307
Property and equipment			4,085
Right of use assets, operating leases			8,826
Goodwill			183,540
Intangible assets			92,300
Other noncurrent assets			10
Accounts payable			(5,450)
Accrued expenses and other current liabilities			(7,147)
Contract liabilities			(1,300)
Short-term lease liabilities, operating leases			(805)
Income tax payable			(1,178)
Deferred tax liabilities			(1,195)
Long-term lease liabilities, operating leases			(8,021)
Other long-term liabilities			(1,015)
Net assets acquired			$ 292,380
QRC Technologies
Business Acquisition [Line Items]
Cash and cash equivalents		$ 5,925
Accounts receivable		5,587
Prepaid expenses and other current assets		5,727
Property and equipment		1,205
Right of use assets, operating leases		5,228
Goodwill		125,091
Intangible assets		76,200
Accounts payable		(1,567)
Accrued expenses and other current liabilities		(4,025)
Short-term lease liabilities, operating leases		(545)
Long-term lease liabilities, operating leases		(4,683)
Net assets acquired		$ 214,143

Acquisitions - Schedule of Intangible Assets Value on Purchase Price (Details) - USD ($) $ in Thousands				12 Months Ended
	Jul. 31, 2019	Jan. 07, 2019	May 31, 2018	Dec. 31, 2019
Minimum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				1 year
Maximum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				10 years
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				4 years
Developed Technology \| Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount			$ 84,900
Amortization Period (in years)			4 years
Developed Technology \| OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 1,300
Amortization Period (in years)		3 years
Developed Technology \| QRC Technologies
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 21,800
Developed Technology \| QRC Technologies \| Minimum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)	3 years
Developed Technology \| QRC Technologies \| Maximum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)	5 years
Customer Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				7 years
Customer Relationships \| Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount			$ 76,000
Amortization Period (in years)			8 years
Customer Relationships \| OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 57,100
Amortization Period (in years)		5 years
Customer Relationships \| QRC Technologies
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 49,800
Amortization Period (in years)	12 years
Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				3 years
Backlog \| Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount			$ 34,900
Amortization Period (in years)			2 years
Backlog \| OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 27,700
Amortization Period (in years)		3 years
Backlog \| QRC Technologies
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 800
Amortization Period (in years)	1 year
Trade Name
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				1 year
Trade Name \| Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount			$ 3,600
Amortization Period (in years)			1 year
Trade Name \| OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 3,800
Amortization Period (in years)		2 years
Trade Name \| QRC Technologies
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 800
Amortization Period (in years)	2 years
Leases
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				5 years
Leases \| Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount			$ 120
Amortization Period (in years)			6 years
Non compete Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)				3 years
Non compete Agreements \| OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 2,400
Amortization Period (in years)		3 years
Non compete Agreements \| QRC Technologies
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,200
Amortization Period (in years)	4 years
In-process Research and Development \| QRC Technologies
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,800
In-process Research and Development \| QRC Technologies \| Minimum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)	3 years
In-process Research and Development \| QRC Technologies \| Maximum
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)	5 years

Acquisitions - Schedule of Supplemental Pro Forma Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Polaris Alpha
Business Acquisition [Line Items]
Pro forma Revenue		$ 3,713,804	$ 3,361,626
Pro forma Net Income including noncontrolling interest		225,861	$ 58,356
OGSystems
Business Acquisition [Line Items]
Pro forma Revenue	$ 3,956,767	3,676,894
Pro forma Net Income including noncontrolling interest	134,046	205,961
QRC Technologies
Business Acquisition [Line Items]
Pro forma Revenue	3,976,361	3,596,920
Pro forma Net Income	$ 138,692	$ 221,930

Contracts with Customers - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Disaggregation Of Revenue [Line Items]
Revenues	$ 1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	$ 3,954,812	$ 3,560,508	$ 3,017,011
Cost-Plus
Disaggregation Of Revenue [Line Items]
Revenues									1,705,832	1,473,815
Time-and-Materials
Disaggregation Of Revenue [Line Items]
Revenues									1,074,037	961,759
Fixed-Price
Disaggregation Of Revenue [Line Items]
Revenues									$ 1,174,943	$ 1,124,934

Contracts with Customers - Contracts with Customers - Summary of Changes in Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Contract assets	$ 575,089	$ 515,319
Contract liabilities	230,681	208,576
Net contract assets (liabilities)	344,408	$ 306,743
Change in contract assets	59,770
Change in contract liabilities	22,105
Change in contract assets and liabilities	$ 37,665
Percentage change in contract assets	11.60%
Percentage change in contract liabilities	10.60%
Percentage change in contract assets and liabilities	12.28%

Contracts with Customers - Summary of Contract Assets and Contract Liabilities (Parenthetical) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Contract retentions	$ 85.5	$ 89.6
Contract retentions, not expected to be paid in next 12 months	41.7
Contract assets, unapproved change orders, claims, and requests	$ 73.0	$ 47.1

Contracts with Customers - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue recognized included contract liability	$ 129,900,000	$ 168,600,000
Impairment of contract assets	0	0
Impact of changes in estimated claims or incentives on revenue	5,000
Increase in revenue due to Impact of changes in estimated claims or incentives	12,100,000	$ 0
Remaining unsatisfied performance obligations	$ 5,000,000,000

Contracts with Customers - Summary of Changes in Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Acquired contract assets	$ 9,747	$ 35,229
Acquired contract liabilities	1,300	3,529
Change in the estimate of variable consideration	12,166	0
Reversal of provision for contract losses	$ 0	$ 133,180

Contracts with Customers - Summary of Changes in Contract Assets and Contract Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Reversal for provision for contract losses	$ 0	$ 133,180
Increase in revenue recorded in other income		$ 55,100

Contracts with Customers - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Billed	$ 494,366	$ 538,808
Unbilled	218,959	135,180
Total accounts receivable, gross	713,325	673,988
Allowance for doubtful accounts	(41,833)	(50,702)
Total accounts receivable, net	$ 671,492	$ 623,286

Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Lessee Lease Description [Line Items]
Lease option to extend	five years
Lease existence of option to extend	true
Lease option to terminate	seventh year
Lease existence of option to terminate	true
Finance lease right-of-use asset	$ 2.4
Finance lease right of use assets accumulated depreciation	0.7
Operating lease not yet commenced expense	9.9
Indirect General And Administrative Expenses
Lessee Lease Description [Line Items]
Rental expense	$ 82.1	$ 79.8	$ 73.3
Minimum
Lessee Lease Description [Line Items]
Lease term of contract	1 year
Operating lease not yet commenced term of contract	5 years
Maximum
Lessee Lease Description [Line Items]
Lease term of contract	11 years
Operating lease not yet commenced term of contract	7 years

Leases - Summary of Lease Costs (Details) $ in Thousands	12 Months Ended
Leases - Summary of Lease Costs (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 70,112
Short-term lease cost	11,988
Amortization of right-of-use assets	746
Interest on lease liabilities	77
Sublease income	(3,620)
Total lease cost	$ 79,303

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating cash flows for operating leases	$ 62,714
Operating cash flows for financing activities	77
Financing cash flows from finance leases	863
Right-of-use assets obtained in exchange for new operating lease liabilities	299,503
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 3,124

Leases - Schedule of Supplemental Balance Sheet and Other Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Operating Leases:
Right-of-use assets	$ 233,415
Lease liabilities:
Current	49,994
Long-term	203,624	$ 0
Total operating lease liabilities	253,618
Finance Leases:
Other noncurrent assets	2,377
Accrued expenses and other current liabilities	$ 1,075
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Other long-term liabilities	$ 1,202	$ 935
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Weighted Average Remaining Lease Term:
Operating leases	6 years
Finance leases	3 years
Weighted Average Discount Rate:
Operating leases	4.00%
Finance leases	4.50%

Leases - Schedule of Maturity Analysis of Future Undiscounted Cash Flows (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Operating Leases
2020	$ 58,412
2021	54,491
2022	48,454
2023	41,424
2024	30,945
Thereafter	49,727
Total lease payments	283,453
Less: imputed interest	(29,835)
Total present value of lease liabilities	253,618
Finance Leases
2020	1,152
2021	870
2022	326
2023	48
Total lease payments	2,396
Less: imputed interest	(119)
Total present value of lease liabilities	$ 2,277

Equity-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense, net of tax benefits	$ 49.0	$ 16.3	$ 18.8
Stock-based compensation expense, tax benefits	16.7	0.2	0.2
Stock-based compensation expense, tax benefit realized related to awards vested	3.3	$ 0.2	$ 0.1
Compensation cost related to non-vested awards not yet recognized	$ 16.5
Vesting period	6 years
Common stock related to employee statutory income tax withholding, shares retired	27,962
Stock Appreciation Rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of years over which share price increase	3 years
Vesting period	3 years
Long-Term Growth Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Share issued	74,704

Equity-Based Compensation - Summary of Assumptions Used in Black-Scholes Options Pricing Model (Details) - Stock Appreciation Rights	12 Months Ended
	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%
Expected volatility	31.00%
Risk-free interest rate	1.60%
Expected term	1 year

Equity-Based Compensation - Summary of Stock Appreciation Right Activity (Details) - Stock Appreciation Rights - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Unvested, Beginning balance	3,416,654	3,395,375	3,170,565
Number of Units, Granted		1,708,746	2,096,439
Number of Units, Vested	(1,547,142)	(1,322,805)	(1,573,998)
Number of Units, Forfeited	(391,884)	(364,662)	(297,631)
Number of Units, Unvested, Ending balance	1,477,628	3,416,654	3,395,375
Weighted Average Grant-Date Fair Value, Unvested, Beginning balance	$ 3.00	$ 3.00	$ 3.00
Weighted Average Grant-Date Fair Value, Granted		3.00	3.00
Weighted Average Grant-Date Fair Value, Vested	3.00	3.00	3.00
Weighted Average Grant-Date Fair Value, Forfeited	3.00	3.00	3.00
Weighted Average Grant-Date Fair Value, Unvested, Ending balance	$ 3.00	$ 3.00	$ 3.00

Equity-Based Compensation - Schedule of Unvested Share Activity (Details) - Long-Term Growth Units - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Unvested, Beginning balance	299,781	307,881	331,986
Number of Units, Granted		144,777	174,270
Number of Units, Vested	(137,760)	(136,221)	(176,781)
Number of Units, Forfeited	(34,584)	(16,656)	(21,594)
Number of Units, Unvested, Ending balance	127,437	299,781	307,881
Weighted Average Grant-Date Fair Value, Unvested, Beginning balance	$ 20.23	$ 20.18	$ 19.65
Weighted Average Grant-Date Fair Value, Granted		22.67	20.33
Weighted Average Grant-Date Fair Value, Vested	20.33	20.00	19.33
Weighted Average Grant-Date Fair Value, Forfeited	21.50	20.27	20.09
Weighted Average Grant-Date Fair Value, Unvested, Ending balance	$ 21.45	$ 20.23	$ 20.18

Equity-Based Compensation - Summary of Restricted Award Unit Activity (Details) - Restricted Award Units - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Unvested, Beginning balance	589,350	659,445	534,355
Number of Units, Granted		262,140	306,843
Number of Units, Vested	(281,805)	(264,408)	(135,982)
Number of Units, Forfeited	(58,101)	(67,827)	(45,771)
Number of Units, Unvested, Ending balance	249,444	589,350	659,445
Weighted Average Grant-Date Fair Value, Unvested, Beginning balance	$ 21.31	$ 20.14	$ 19.85
Weighted Average Grant-Date Fair Value, Granted		22.67	20.33
Weighted Average Grant-Date Fair Value, Vested	20.33	20.00	19.53
Weighted Average Grant-Date Fair Value, Forfeited	21.31	20.34	19.90
Weighted Average Grant-Date Fair Value, Unvested, Ending balance	$ 22.40	$ 21.31	$ 20.14

Equity-Based Compensation - Schedule of Amount Paid for Cash Settled Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total cash settled awards	$ 11,906	$ 10,110	$ 11,051
Stock Appreciation Rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total cash settled awards	5,261	4,576	170
Long-Term Growth Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total cash settled awards	1,108	1,095	8,246
Restricted Award Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total cash settled awards	$ 5,537	$ 4,439	$ 2,635

Equity-Based Compensation - Summary of Restricted Stock Unit Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Restricted Stock Units (Service Condition)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted \| shares	270,544
Weighted Average Grant-Date Fair Value, Granted \| $ / shares	$ 34.11
Number of Units, Unvested, Ending balance \| shares	189,090
Weighted Average Grant-Date Fair Value, Unvested, Ending balance \| $ / shares	$ 34.15
Restricted Stock Units (Service and Performance Condition)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted \| shares	327,675
Weighted Average Grant-Date Fair Value, Granted \| $ / shares	$ 34.02
Number of Units, Unvested, Ending balance \| shares	317,550
Weighted Average Grant-Date Fair Value, Unvested, Ending balance \| $ / shares	$ 34.02
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, Granted \| shares	598,219
Weighted Average Grant-Date Fair Value, Granted \| $ / shares	$ 34.06
Number of Units, Vested \| shares	(74,704)
Number of Units, Forfeited \| shares	(16,875)
Number of Units, Unvested, Ending balance \| shares	506,640
Weighted Average Grant-Date Fair Value, Vested \| $ / shares	$ 34.02
Weighted Average Grant-Date Fair Value, Forfeited \| $ / shares	34.02
Weighted Average Grant-Date Fair Value, Unvested, Ending balance \| $ / shares	$ 34.07

Equity-Based Compensation - Summary of Restricted Stock Outstanding (Details) shares in Thousands	Dec. 31, 2019 $ / shares shares
Restricted Stock Units (Service Condition)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares \| shares	189,090
Weighted Average Grant-Date Fair Value \| $ / shares	$ 34.15
Restricted Stock Units (Service and Performance Condition)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares \| shares	317,550
Weighted Average Grant-Date Fair Value \| $ / shares	$ 34.02

Goodwill - Summary of Changes in Carrying Value of Goodwill by Reporting Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Beginning Balance	$ 736,938	$ 496,786
Acquisitions	308,564	244,402
Foreign Exchange	1,923	(4,250)
Ending Balance	1,047,425	736,938
Federal Solutions
Goodwill [Line Items]
Beginning Balance	666,841	422,439
Acquisitions	308,564	244,402
Foreign Exchange	0	0
Ending Balance	975,405	666,841
Critical Infrastructure
Goodwill [Line Items]
Beginning Balance	70,097	74,347
Acquisitions	0	0
Foreign Exchange	1,923	(4,250)
Ending Balance	$ 72,020	$ 70,097

Goodwill - Additional Information (Details) - USD ($)	12 Months Ended
Goodwill - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill impairments	$ 0	$ 0

Intangible Assets - Schedule of Gross Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 463,268	$ 294,492
Accumulated Amortization	(203,410)	(115,104)
Net Carrying Amount	259,858	179,388
Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	109,255	80,754
Accumulated Amortization	(87,510)	(58,295)
Net Carrying Amount	$ 21,745	22,459
Amortization Period (in years)	3 years
Customer Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 228,529	121,629
Accumulated Amortization	(67,809)	(38,974)
Net Carrying Amount	$ 160,720	82,655
Amortization Period (in years)	7 years
Leases
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 670	670
Accumulated Amortization	(580)	(561)
Net Carrying Amount	$ 90	109
Amortization Period (in years)	5 years
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 110,939	87,839
Accumulated Amortization	(40,749)	(15,174)
Net Carrying Amount	$ 70,190	72,665
Amortization Period (in years)	4 years
Trade Name
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,200	3,600
Accumulated Amortization	(5,667)	(2,100)
Net Carrying Amount	$ 2,533	1,500
Amortization Period (in years)	1 year
Non compete Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,600	0
Accumulated Amortization	(925)	0
Net Carrying Amount	$ 2,675	0
Amortization Period (in years)	3 years
In Process Research and Development
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,800	0
Accumulated Amortization	0	0
Net Carrying Amount	1,800	0
Other Intangibles
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	275	0
Accumulated Amortization	(170)	0
Net Carrying Amount	$ 105	$ 0
Amortization Period (in years)	10 years

Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 88.3	$ 37.4	$ 5.6

Intangible Assets - Schedule of Estimated Amortization Expense (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2020	$ 86,574
2021	81,591
2022	36,100
2023	23,549
2024	9,098
Thereafter	21,146
Finite-Lived Intangible Assets, Net	$ 258,058

Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 348,711	$ 296,382
Less: Accumulated depreciation	(225,960)	(204,533)
Property and equipment, net	122,751	91,849	$ 87,578
Buildings and Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 81,065	54,348
Buildings and Leasehold Improvements \| Minimum
Property Plant And Equipment [Line Items]
Useful lives (years)	1 year
Buildings and Leasehold Improvements \| Maximum
Property Plant And Equipment [Line Items]
Useful lives (years)	15 years
Furniture and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 91,720	81,705
Furniture and Equipment \| Minimum
Property Plant And Equipment [Line Items]
Useful lives (years)	3 years
Furniture and Equipment \| Maximum
Property Plant And Equipment [Line Items]
Useful lives (years)	10 years
Computer Systems and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 164,161	148,255
Computer Systems and Equipment \| Minimum
Property Plant And Equipment [Line Items]
Useful lives (years)	3 years
Computer Systems and Equipment \| Maximum
Property Plant And Equipment [Line Items]
Useful lives (years)	10 years
Construction Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 11,765	$ 12,074
Construction Equipment \| Minimum
Property Plant And Equipment [Line Items]
Useful lives (years)	5 years
Construction Equipment \| Maximum
Property Plant And Equipment [Line Items]
Useful lives (years)	7 years

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Property Plant And Equipment [Abstract]
Depreciation expense	$ 37.3	$ 32.4	$ 29.4

Sale-Leasebacks - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended				12 Months Ended
	Jan. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 28, 2018 USD ($)	Jun. 29, 2018 USD ($)	Mar. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 29, 2017 USD ($)	Dec. 31, 2011 USD ($) Sale-leaseback building
Sale Leaseback Transaction [Line Items]
Sale leaseback transaction, description						During fiscal 2011, the Company consummated two sale-leaseback transactions associated with the sale of two office buildings
Number of sale leaseback transactions consummated \| Sale-leaseback									2
Number of sale leaseback transaction associated with sale \| building									2
Gain recognized to the sale leaseback transaction									$ 106,700
Deferred gain resulting from sale-leaseback transactions		$ 46,004					$ 46,004		$ 107,800
Amortization of deferred gain		(1,813)	$ (1,798)	$ (1,829)	$ (1,813)		7,253	$ 7,283
Accounting Standards Update 2016-02
Sale Leaseback Transaction [Line Items]
Deferred gain balance recognized		$ 53,300					$ 53,300
Adjustment due to adoption of ASC						$ 52,608
Accounting Standards Update 2016-02 \| Deferred Tax Asset
Sale Leaseback Transaction [Line Items]
Adjustment due to adoption of ASC	$ 700					$ 700

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Salaries and wages	$ 46,685	$ 50,991
Employee benefits	259,081	214,008
Self-insurance liability	29,997	29,682
Project cost accruals	217,729	183,362
Other accrued expenses	86,371	81,657
Total accrued expenses and other current liabilities	$ 639,863	$ 559,700

Debt and Credit Facilities - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-Term Debt issuance costs	$ (647)	$ (836)
Long-term debt	249,353	429,164
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt		180,000
Senior Notes
Debt Instrument [Line Items]
Long-term debt	$ 250,000	$ 250,000

Debt and Credit Facilities - Additional Information (Details) - USD ($)		12 Months Ended
	Jul. 01, 2014	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Debt Instrument [Line Items]
Debt issuance costs incurred		$ 500,000
Letters of credit outstanding amount		197,300,000	$ 223,000,000
Amortization of debt issuance costs		973,000	721,000	$ 504,000
Term Loan
Debt Instrument [Line Items]
Repayment of outstanding balance		150,000,000
Accrued Expenses and Other Current Liabilities
Debt Instrument [Line Items]
Interest payable		5,700,000	5,700,000
Senior Notes
Debt Instrument [Line Items]
Interest expense		12,400,000	12,400,000	12,400,000
Interest payments		12,400,000	$ 12,400,000	$ 12,400,000
Private Placement
Debt Instrument [Line Items]
Debt issuance costs incurred		$ 1,100,000
Repayment of outstanding balance	$ 250,000,000
Credit Agreement
Debt Instrument [Line Items]
Amended and restated credit agreement date		Nov. 30, 2017
Debt issuance costs incurred		$ 2,000,000
Revolving credit facility		500,000,000
Increase in revolving credit facility		$ 550,000,000
Credit agreement extended date		Nov. 30, 2022
Interest rate		3.02%	4.253%
Letters of credit outstanding amount		$ 43,700,000	$ 49,800,000
Credit Agreement \| Base Rate \| Minimum
Debt Instrument [Line Items]
Margin interest rate		0.125%
Credit Agreement \| Base Rate \| Maximum
Debt Instrument [Line Items]
Margin interest rate		1.00%
Credit Agreement \| LIBOR \| Minimum
Debt Instrument [Line Items]
Margin interest rate		1.125%
Credit Agreement \| LIBOR \| Maximum
Debt Instrument [Line Items]
Margin interest rate		2.00%

Debt and Credit Facilities - Schedule of Aggregate Amount Debt Repayable (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Senior Note, Series A
Debt Instrument [Line Items]
Debt Amount	$ 50,000
Maturity Date	Jul. 15, 2021
Interest Rate	4.44%
Senior Note, Series B
Debt Instrument [Line Items]
Debt Amount	$ 100,000
Maturity Date	Jul. 15, 2024
Interest Rate	4.98%
Senior Note, Series C
Debt Instrument [Line Items]
Debt Amount	$ 60,000
Maturity Date	Jul. 15, 2026
Interest Rate	5.13%
Senior Note, Series D
Debt Instrument [Line Items]
Debt Amount	$ 40,000
Maturity Date	Jul. 15, 2029
Interest Rate	5.38%

Other Long-term Liabilities - Schedule of Other Long-term Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Self-insurance liability	$ 102,521	$ 99,813
Deferred rent		15,966
Reserve for uncertain tax positions	14,427	9,890
Finance lease obligations	1,202	935
Other long-term liabilities	7,554	1,259
Total other long-term liabilities	$ 125,704	$ 127,863

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Income Taxes [Line Items]
U.S. corporate tax rate	21.00%	21.00%	35.00%
Effective income tax rate	(104.00%)	8.00%	16.00%
Deferred tax benefit related to remeasurement due to change in tax status	$ 93,900,000
Valuation allowance related to foreign tax credits	6,300,000
Deferred tax assets, valuation allowance	17,358,000	$ 6,668,000
Deferred tax assets, increase in valuation allowance	10,700,000
Deferred tax assets recorded for foreign tax credit carryforwards	8,100,000
Net operating loss carryforwards	16,400,000	14,855,000
Unrecognized tax benefits that would impact effective tax rate	13,900,000	9,900,000
Unrecognized tax benefits, income tax penalties and interest expense	1,300,000	100,000
Unrecognized tax benefits, income tax penalties and interest accrued	3,400,000	$ 2,000,000	$ 1,900,000
U.S. Federal
Income Taxes [Line Items]
Net operating loss carryforwards	29,700,000
Net operating loss carryforwards, not subject to expiration	$ 29,700,000
U.S. Federal \| Earliest Tax Year
Income Taxes [Line Items]
Open tax year	2016
U.S. States
Income Taxes [Line Items]
Net operating loss carryforwards	$ 28,200,000
Net operating loss carryforwards, not subject to expiration	26,600,000
Foreign
Income Taxes [Line Items]
Net operating loss carryforwards	41,500,000
Net operating loss carryforwards, not subject to expiration	35,500,000
Foreign tax credit carryforwards	8,500
Foreign tax credits, valuation allowance	$ 8,500
Foreign tax credits, expiration year	2029
U.S. States and Foreign
Income Taxes [Line Items]
Net operating loss carryforwards, expiration description	expire if not used between 2020 and 2040.
U.S. States and Foreign \| Minimum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year	2020
U.S. States and Foreign \| Maximum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year	2040

Income Taxes - Components of Income from Continuing Operations Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Income Taxes [Line Items]
Income before income tax expense	$ 67,242	$ 259,803	$ 133,001
United States Earnings
Income Taxes [Line Items]
Income before income tax expense	6,762	205,418	85,913
Foreign Earnings
Income Taxes [Line Items]
Income before income tax expense	$ 60,480	$ 54,385	$ 47,088

Income Taxes - Schedule of Income Tax Expense (Benefit) Attributable to Income from Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Current
Federal									$ 22,865
State									10,428	$ 1,536	$ 1,579
Foreign									20,159	20,253	14,482
Total current income tax expense									53,452	21,789	16,061
Deferred
Federal									(97,299)
State									(27,432)	2,329	(569)
Foreign									1,393	(3,751)	5,972
Total deferred tax expense (benefit)									(123,338)	(1,422)	5,403
Total income tax expense (benefit)	$ (2,823)	$ (15,453)	$ (53,496)	$ 1,886	$ 1,841	$ 4,154	$ 9,019	$ 5,353	$ (69,886)	$ 20,367	$ 21,464

Income Taxes - Computation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Income Tax Disclosure [Abstract]
Income before income tax expense (benefit)									$ 67,242	$ 259,803	$ 133,001
Tax at federal statutory tax rate									14,121	54,559	46,550
S- corporation exclusion									(4,875)	(39,539)	(25,109)
State taxes, net of federal tax benefit									3,223	3,865	1,010
Change in tax status									(93,878)
Change in valuation allowance									4,502	(2,215)	1,438
Change in uncertain tax positions									4,118	629	(34)
Foreign tax rate differential									4,886	4,168	(907)
Foreign tax credits									(1,313)
Transaction costs									1,052
Other permanent items, net									1,182
Noncontrolling interests									(2,282)	(3,599)	(4,960)
Other, net									(622)	2,499	3,476
Total income tax expense (benefit)	$ (2,823)	$ (15,453)	$ (53,496)	$ 1,886	$ 1,841	$ 4,154	$ 9,019	$ 5,353	$ (69,886)	$ 20,367	$ 21,464
Tax at federal statutory tax rate									21.00%	21.00%	35.00%
S- corporation exclusion									(7.00%)	(15.00%)	(19.00%)
State taxes, net of federal tax benefit									5.00%	1.00%	1.00%
Change in tax status									(140.00%)
Change in valuation allowance									7.00%	(1.00%)	1.00%
Change in uncertain tax positions									6.00%	0.00%	0.00%
Foreign tax rate differential									7.00%	2.00%	(1.00%)
Foreign tax credits									(2.00%)
Transaction costs									1.00%
Other permanent items, net									2.00%
Noncontrolling interests									(3.00%)	(1.00%)	(4.00%)
Other, net									(1.00%)	1.00%	3.00%
Total income tax expense (benefit)									(104.00%)	8.00%	16.00%

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Project and non-project reserves	$ 34,225	$ 2,326
Employee compensation and benefits	59,624	1,609
Revenue and cost recognition	33,588
Insurance accruals	19,204	962
Net operating losses	16,400	14,855
Lease liabilities	68,447	205
Tax credit carryforwards	8,969	377
Other	3,318	2,240
Valuation allowance	(17,358)	(6,668)
Total deferred tax assets	226,417	15,906
Deferred tax liabilities
Intangible assets	(29,543)	(2,529)
Right of use assets	(63,032)
Revenue and cost recognition		(10,570)
Other	(13,063)	(3,367)
Total deferred tax liabilities	(105,638)	(16,466)
Net deferred tax (liabilities)		$ (560)
Net deferred tax assets	$ 120,779

Income Taxes - Reconciliation of Beginning and Ending Balances of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Income Tax Uncertainties [Abstract]
Beginning of year	$ 7,845	$ 7,137	$ 7,827
Increases—current year tax positions	7,531	1,094	1,134
Increases—prior year tax positions	1,379	1,301	319
Decreases—prior year tax positions	(991)	(1,656)	(1,629)
Settlements	(124)		(361)
Lapse of statute of limitations	(114)	(31)	(153)
End of year	$ 15,526	$ 7,845	$ 7,137

Contingencies - Additional Information (Details) - Minimum $ in Millions		12 Months Ended
	Mar. 01, 2017 USD ($)	Dec. 31, 2019 Claim
Legal Proceedings [Line Items]
Number of claims outstanding \| Claim		0
Loss contingency damages value \| $	$ 100.0

Retirement and Other Benefit Plans - Additional Information (Details) - USD ($)			12 Months Ended
	Apr. 15, 2019	Apr. 03, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares fully vested, Description			Shares allocated to a participant’s account are fully vested after six years of credited service, or in the event(s) of reaching age 65, death or disability while an active employee of the Company.
Shares fully vested after credited service			6 years
Common stock shares outstanding including ESOP			100,669,694
Company's stock held by ESOP			78,896,806	78,172,809
ESOP shares redemption, value				$ 1,900,000,000
ESOP dividends declared date		Apr. 03, 2019
ESOP dividends declared per share		$ 2.00
ESOP dividends declared amount		$ 52,100,000
ESOP dividends payment date		May 10, 2019
Common stock dividend ratio	200.00%
Dividends declared date	Apr. 15, 2019
Dividends payment, date	May 08, 2019
Dividends record date	May 07, 2019
Dividends declared amount				0	$ 0
Contribution to 401 (k) plan			$ 25,200,000	17,100,000	15,800,000
Other Noncurrent Assets
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Defined benefit pension plan, net assets position			2,100,000	1,700,000
Direct Costs of Contracts and Indirect, General and Administrative Expense
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
ESOP contribution expense			$ 55,500,000	$ 45,200,000	$ 40,600,000

Investments in and Advances to Joint Ventures - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Schedule Of Equity Method Investments [Line Items]
Letters of credit outstanding amount	$ 197.3	$ 223.0
Unconsolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Net distributions from unconsolidated joint ventures	38.9	41.9	$ 31.8
Consolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Letters of credit outstanding amount	$ 55.0	$ 76.8

Investments in and Advances to Joint Ventures - Summary of Financial Information for Consolidated Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 1,526,409				$ 1,488,807				$ 1,526,409	$ 1,488,807
Total assets	3,450,368				2,612,578				3,450,368	2,612,578
Current liabilities	1,144,382				1,006,161				1,144,382	1,006,161
Total liabilities	1,789,612				1,657,345				1,789,612	1,657,345
Total joint venture equity	1,629,890				(967,537)				1,629,890	(967,537)
Revenue	1,037,388	$ 1,023,277	$ 989,742	$ 904,405	928,940	$ 976,157	$ 900,732	$ 754,679	3,954,812	3,560,508	$ 3,017,011
Costs									3,123,062	2,795,005	2,400,140
Net income attributable to Parsons Corporation	13,722	56,812	40,259	9,741	7,447	41,222	148,381	25,287	120,534	222,337	97,326
Net income attributable to noncontrolling interests	8,582	$ 4,481	$ (114)	$ 3,645	6,783	$ 4,844	$ 1,657	$ 3,815	16,594	17,099	14,211
Consolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Current assets	255,167				287,227				255,167	287,227
Noncurrent assets	2,860				2,689				2,860	2,689
Total assets	258,027				289,916				258,027	289,916
Current liabilities	193,583				199,833				193,583	199,833
Total liabilities	193,583				199,833				193,583	199,833
Total joint venture equity	$ 64,444				$ 90,083				64,444	90,083
Revenue									473,486	540,345	446,506
Costs									435,947	376,628	426,245
Net income attributable to Parsons Corporation									37,539	163,717	20,261
Net income attributable to noncontrolling interests									$ 16,594	$ 17,099	$ 14,211

Investments in and Advances to Joint Ventures - Summary of Financial Information for Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 1,526,409				$ 1,488,807				$ 1,526,409	$ 1,488,807
Total assets	3,450,368				2,612,578				3,450,368	2,612,578
Current liabilities	1,144,382				1,006,161				1,144,382	1,006,161
Total liabilities	1,789,612				1,657,345				1,789,612	1,657,345
Total joint venture equity	1,629,890				(967,537)				1,629,890	(967,537)
Investments in and advances to unconsolidated joint ventures	68,620				63,560				68,620	63,560
Revenue	1,037,388	$ 1,023,277	$ 989,742	$ 904,405	928,940	$ 976,157	$ 900,732	$ 754,679	3,954,812	3,560,508	$ 3,017,011
Costs									3,123,062	2,795,005	2,400,140
Net income attributable to Parsons Corporation	13,722	$ 56,812	$ 40,259	$ 9,741	7,447	$ 41,222	$ 148,381	$ 25,287	120,534	222,337	97,326
Equity in earnings of unconsolidated joint ventures									41,721	36,915	40,086
Unconsolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Current assets	801,335				707,457				801,335	707,457
Noncurrent assets	564,160				876,385				564,160	876,385
Total assets	1,365,495				1,583,842				1,365,495	1,583,842
Current liabilities	655,495				560,306				655,495	560,306
Noncurrent liabilities	507,131				813,269				507,131	813,269
Total liabilities	1,162,626				1,373,575				1,162,626	1,373,575
Total joint venture equity	202,869				210,267				202,869	210,267
Investments in and advances to unconsolidated joint ventures	$ 68,620				$ 63,560				68,620	63,560
Revenue									2,081,341	1,773,037	2,114,903
Costs									1,903,582	1,661,232	1,988,569
Net income attributable to Parsons Corporation									177,759	111,805	126,334
Equity in earnings of unconsolidated joint ventures									$ 41,721	$ 36,915	$ 40,086

Related Party Transactions - Additional Information (Details) - Unconsolidated joint ventures - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Related Party Transaction [Line Items]
Revenues	$ 157.3	$ 144.7	$ 112.1
Reimbursable cost incurred	$ 119.1	$ 111.1	$ 81.8

Related Party Transactions - Schedule of Consolidated Balance Sheet Related to Services Provided to Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Contract assets	$ 575,089	$ 515,319
Contract liabilities	230,681	208,576
Unconsolidated Joint Ventures
Related Party Transaction [Line Items]
Accounts receivable	37,425	38,742
Contract assets	6,955	2,648
Contract liabilities	$ 4,509	$ 10,861

Fair Value of Financial Instruments - Summary of Assets Associated with Pension Plan (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	$ 13,768	$ 13,068
Mutual Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,987	2,539
Fixed Income
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	10,447	10,168
Cash and Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	334	361
Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	3,321	2,900
Level 1 \| Mutual Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,987	2,539
Level 1 \| Fixed Income
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Level 1 \| Cash and Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	334	361
Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	10,447	10,168
Level 2 \| Mutual Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Level 2 \| Fixed Income
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	10,447	10,168
Level 2 \| Cash and Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Level 3 \| Mutual Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Level 3 \| Fixed Income
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Level 3 \| Cash and Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	$ 0	$ 0

Fair Value of Financial Instruments - Summary of Redeemable Common Stock Associated with ESOP (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable Common Stock	$ 1,876,309
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable Common Stock	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable Common Stock	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable Common Stock	$ 1,876,309

Fair Value of Financial Instruments - Additional Information (Details) $ in Billions	Dec. 31, 2018 USD ($) shares
Fair Value Disclosures [Abstract]
Shares held by ESOP \| shares	78,172,809
Shares held by ESOP, redemption values \| $	$ 1.9

Fair Value of Financial Instruments - Schedule of Reconciliation Fair Value Measurements Using Significant Unobservable Inputs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Transfers Net [Abstract]
Balance at beginning of year	$ 1,876,309	$ 1,855,305
Purchases of treasury stock	(6,219)	(125,814)
Contributions of treasury stock to ESOP		47,043
Share price adjustment	883,436	99,775
Transfer to permanent equity	$ (2,753,526)
Balance at end of year		$ 1,876,309

Earnings Per Share - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 29, 2017
Earnings Per Share [Abstract]
Dilutive securities outstanding	0	0

Earnings Per Share - Schedule of Weighted Average Number of Shares Used To Compute Basic and Diluted EPS (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Earnings Per Share [Abstract]
Basic weighted average number of shares outstanding	92,419	80,014	83,574
Dilutive common share equivalents	334	0	0
Diluted weighted average number of shares outstanding	92,753	80,014	83,574

Segments Information - Additional Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 28, 2018 USD ($)	Jun. 29, 2018 USD ($)	Mar. 30, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 28, 2018 USD ($)	Dec. 29, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment									2
Revenues	$ 1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	$ 3,954,812	$ 3,560,508		$ 3,017,011
Property and equipment, net	122,751				91,849				122,751	91,849		87,578
Litigation-related expenses							(132,004)	2,330	0	129,674		0
Critical Infrastructure
Segment Reporting Information [Line Items]
Revenues	536,965	$ 537,102	$ 511,245	$ 481,593	526,058	$ 532,432	559,667	$ 463,344	2,066,905	2,081,501		1,937,105
Revenue Excluding Claim Settlement										2,000,000
Critical Infrastructure \| Mobility Solutions
Segment Reporting Information [Line Items]
Revenues									1,120,563	1,183,863		1,102,725
Revenue Excluding Claim Settlement										1,100,000
Revenue
Segment Reporting Information [Line Items]
Litigation-related expenses							$ (55,100)			55,100
Revenue \| Critical Infrastructure \| Mobility Solutions
Segment Reporting Information [Line Items]
Litigation-related expenses											$ 55,100
United States
Segment Reporting Information [Line Items]
Revenues									3,000,000	2,600,000		2,100,000
Property and equipment, net	$ 109,900				$ 79,900				$ 109,900	$ 79,900		$ 76,200

Segments Information - Summary of Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	$ 3,954,812	$ 3,560,508	$ 3,017,011
Federal Solution Segment
Segment Reporting Information [Line Items]
Total revenues	500,423	486,175	478,497	422,812	402,882	443,725	341,065	291,335	1,887,907	1,479,007	1,079,906
Critical Infrastructure
Segment Reporting Information [Line Items]
Total revenues	$ 536,965	$ 537,102	$ 511,245	$ 481,593	$ 526,058	$ 532,432	$ 559,667	$ 463,344	$ 2,066,905	$ 2,081,501	$ 1,937,105

Segments Information - Summary of Adjusted EBITDA Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Adjusted EBITDA attributable to Parsons Corporation
Adjusted EBITDA attributable to Parsons Corporation	$ 87,828	$ 88,990	$ 76,205	$ 72,024	$ 54,215	$ 88,564	$ 52,635	$ 50,830	$ 307,951	$ 228,837	$ 194,756
Adjusted EBITDA attributable to noncontrolling interests	(8,712)	(4,655)	20	(3,749)	(6,726)	(5,002)	(1,759)	(3,920)	17,096	17,407	14,891
Depreciation and amortization	(33,008)	(31,027)	(31,074)	(30,591)	(23,213)	(23,599)	(14,048)	(9,009)	(125,700)	(69,869)	(35,198)
Interest expense, net	(3,981)	(4,482)	(6,151)	(7,815)	(6,015)	(5,589)	(3,270)	(3,258)	(22,429)	(18,132)	(13,333)
Income tax (expense) benefit	2,823	15,453	53,496	(1,886)	(1,841)	(4,154)	(9,019)	(5,353)	69,886	(20,367)	(21,464)
Litigation-related expenses										129,674	(10,026)
Amortization of deferred gain resulting from sale- leaseback transactions					(1,813)	(1,798)	(1,829)	(1,813)		7,253	7,283
Equity-based compensation	(20,240)	1,657	(43,311)	(3,850)	(3,289)	(5,049)	(5,049)	(3,100)	(65,744)	(16,487)	(19,016)
Transaction-related costs	(7,392)	(9,891)	(7,715)	(9,355)	(5,431)	(2,456)	(4,930)	(125)	(34,353)	(12,942)	(1,190)
Restructuring	(544)	(309)	(353)	(2,218)					(3,424)
Other	(3,182)	902	(952)	(2,923)	(2,009)	(3,449)	(114)	(366)	(6,155)	(5,938)	(5,166)
Net income including noncontrolling interests									137,128	239,436	111,537
Net income attributable to noncontrolling interests	(8,582)	(4,481)	114	(3,645)	(6,783)	(4,844)	(1,657)	(3,815)	(16,594)	(17,099)	(14,211)
Net income attributable to Parsons Corporation	13,722	56,812	40,259	9,741	7,447	41,222	148,381	25,287	120,534	222,337	97,326
Federal Solution Segment
Adjusted EBITDA attributable to Parsons Corporation
Adjusted EBITDA attributable to Parsons Corporation	42,442	50,359	35,700	40,599	20,934	45,556	33,947	21,549	169,100	121,986	95,354
Critical Infrastructure
Adjusted EBITDA attributable to Parsons Corporation
Adjusted EBITDA attributable to Parsons Corporation	$ 36,674	$ 33,976	$ 40,525	$ 27,676	$ 26,555	$ 38,006	$ 16,929	$ 25,361	$ 138,851	$ 106,851	$ 99,402

Segments Information - Summary of Adjusted EBITDA Business Segment Information (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Segment Reporting Information [Line Items]
Reversal of accrued liability	$ (132,004)	$ 2,330	$ 0	$ 129,674	$ 0
Other Income
Segment Reporting Information [Line Items]
Reversal of accrued liability	(74,600)			74,600
Revenue
Segment Reporting Information [Line Items]
Reversal of accrued liability	$ (55,100)			$ 55,100

Segments Information - Summary of Revenues and Property and Equipment, Net by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	$ 3,954,812	$ 3,560,508	$ 3,017,011
Property and equipment, net	122,751				91,849				122,751	91,849	87,578
North America
Segment Reporting Information [Line Items]
Revenues									3,249,054	2,870,494	2,374,138
Property and equipment, net	117,606				86,847				117,606	86,847	80,852
Middle East
Segment Reporting Information [Line Items]
Revenues									689,067	671,925	621,796
Property and equipment, net	$ 5,145				$ 5,002				5,145	5,002	6,726
Rest of World
Segment Reporting Information [Line Items]
Revenues									$ 16,691	$ 18,089	$ 21,077

Segments Information - Summary of Revenues by Business Lines (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	$ 3,954,812	$ 3,560,508	$ 3,017,011
Federal Solution Segment
Segment Reporting Information [Line Items]
Revenues	500,423	486,175	478,497	422,812	402,882	443,725	341,065	291,335	1,887,907	1,479,007	1,079,906
Federal Solution Segment \| Cyber & Intelligence
Segment Reporting Information [Line Items]
Revenues									351,828	255,447	184,771
Federal Solution Segment \| Defense
Segment Reporting Information [Line Items]
Revenues									577,109	431,059	291,358
Federal Solution Segment \| Mission Solutions
Segment Reporting Information [Line Items]
Revenues									317,802	360,969	291,933
Federal Solution Segment \| Engineered Systems
Segment Reporting Information [Line Items]
Revenues									497,793	431,532	311,844
Federal Solution Segment \| Geospatial
Segment Reporting Information [Line Items]
Revenues									143,375
Critical Infrastructure
Segment Reporting Information [Line Items]
Revenues	$ 536,965	$ 537,102	$ 511,245	$ 481,593	$ 526,058	$ 532,432	$ 559,667	$ 463,344	2,066,905	2,081,501	1,937,105
Critical Infrastructure \| Connect Communities
Segment Reporting Information [Line Items]
Revenues									619,220	656,513	602,975
Critical Infrastructure \| Mobility Solutions
Segment Reporting Information [Line Items]
Revenues									1,120,563	1,183,863	1,102,725
Critical Infrastructure \| Industrial
Segment Reporting Information [Line Items]
Revenues									$ 327,122	$ 241,125	$ 231,405

Quarterly Information - Unaudited - Schedule of Selected Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Quarterly Financial Information [Line Items]
Total revenues	$ 1,037,388	$ 1,023,277	$ 989,742	$ 904,405	$ 928,940	$ 976,157	$ 900,732	$ 754,679	$ 3,954,812	$ 3,560,508	$ 3,017,011
Operating income	24,274	53,449	(8,706)	23,046	24,092	55,113	86,912	38,891	92,063	205,008	150,702
Net income attributable to Parsons Corporation	13,722	56,812	40,259	9,741	7,447	41,222	148,381	25,287	120,534	222,337	97,326
Adjusted EBITDA attributable to Parsons Corporation	87,828	88,990	76,205	72,024	54,215	88,564	52,635	50,830	307,951	228,837	194,756
Adjusted EBITDA attributable to noncontrolling interests	$ 8,712	$ 4,655	$ (20)	$ 3,749	$ 6,726	$ 5,002	$ 1,759	$ 3,920	$ (17,096)	$ (17,407)	$ (14,891)
Earnings per share:
Basic	$ 0.14	$ 0.57	$ 0.44	$ 0.12	$ 0.10	$ 0.52	$ 1.83	$ 0.31	$ 1.30	$ 2.78	$ 1.16
Diluted	$ 0.14	$ 0.57	$ 0.44	$ 0.12	$ 0.10	$ 0.52	$ 1.83	$ 0.31	$ 1.30	$ 2.78	$ 1.16
Federal Solution Segment
Quarterly Financial Information [Line Items]
Total revenues	$ 500,423	$ 486,175	$ 478,497	$ 422,812	$ 402,882	$ 443,725	$ 341,065	$ 291,335	$ 1,887,907	$ 1,479,007	$ 1,079,906
Adjusted EBITDA attributable to Parsons Corporation	42,442	50,359	35,700	40,599	20,934	45,556	33,947	21,549	169,100	121,986	95,354
Critical Infrastructure
Quarterly Financial Information [Line Items]
Total revenues	536,965	537,102	511,245	481,593	526,058	532,432	559,667	463,344	2,066,905	2,081,501	1,937,105
Adjusted EBITDA attributable to Parsons Corporation	$ 36,674	$ 33,976	$ 40,525	$ 27,676	$ 26,555	$ 38,006	$ 16,929	$ 25,361	$ 138,851	$ 106,851	$ 99,402

Quarterly Information - Unaudited - Schedule of Selected Quarterly Financial Information (Parenthetical) (Details) - Critical Infrastructure $ in Millions	3 Months Ended
	Jun. 29, 2018 USD ($)
Quarterly Financial Information [Line Items]
Increase in revenue	$ 55.1
Increase in other income	$ 74.6

Quarterly Information - Unaudited - Net Income (Loss) To Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Quarterly Financial Information Disclosure [Abstract]
Net income attributable to Parsons Corporation	$ 13,722	$ 56,812	$ 40,259	$ 9,741	$ 7,447	$ 41,222	$ 148,381	$ 25,287	$ 120,534	$ 222,337	$ 97,326
Interest expense, net	3,981	4,482	6,151	7,815	6,015	5,589	3,270	3,258	22,429	18,132	13,333
Income tax expense (benefit)	(2,823)	(15,453)	(53,496)	1,886	1,841	4,154	9,019	5,353	(69,886)	20,367	21,464
Depreciation and amortization	33,008	31,027	31,074	30,591	23,213	23,599	14,048	9,009	125,700	69,869	35,198
Net income attributable to noncontrolling interests	8,582	4,481	(114)	3,645	6,783	4,844	1,657	3,815	16,594	17,099	14,211
Litigation-related expenses							(132,004)	2,330	0	129,674	0
Amortization of deferred gain resulting from sale- leaseback transactions					(1,813)	(1,798)	(1,829)	(1,813)		7,253	7,283
Stock-based compensation	20,240	(1,657)	43,311	3,850	3,289	5,049	5,049	3,100	65,744	16,487	19,016
Transaction related costs	7,392	9,891	7,715	9,355	5,431	2,456	4,930	125	34,353	12,942	1,190
Restructuring	544	309	353	2,218					3,424
Other	3,182	(902)	952	2,923	2,009	3,449	114	366	6,155	5,938	5,166
Adjusted EBITDA attributable to Parsons Corporation	$ 87,828	$ 88,990	$ 76,205	$ 72,024	$ 54,215	$ 88,564	$ 52,635	$ 50,830	$ 307,951	$ 228,837	$ 194,756

Quarterly Information - Unaudited - Net Income (Loss) To Adjusted EBITDA (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Quarterly Financial Information [Line Items]
Gain associated with claim on long-term contract	$ 132,004	$ (2,330)	$ 0	$ (129,674)	$ 0
Revenue
Quarterly Financial Information [Line Items]
Gain associated with claim on long-term contract	55,100			(55,100)
Other Income
Quarterly Financial Information [Line Items]
Gain associated with claim on long-term contract	$ 74,600			$ (74,600)

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 29, 2017
Allowance for Doubtful Accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 50,702	$ 52,911	$ 40,368
Additions	2,794	5,254	12,530
Deductions	(10,661)	(6,085)	(2,730)
Other and foreign exchange impact	(1,002)	(1,378)	2,743
Balance at end of period	41,833	50,702	52,911
Valuation Allowance on Deferred Tax Assets
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	6,668	8,882	7,444
Additions	10,817	452	3,456
Deductions	(32)	(2,633)	(2,168)
Other and foreign exchange impact	(94)	(33)	150
Balance at end of period	$ 17,359	$ 6,668	$ 8,882

Contracts with Customers - Summary of Remaining Unsatisfied Performance Obligations Expect to Satisfy (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 5,000,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 2,842,525
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,083,551
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,036,069
Revenue, remaining performance obligation, expected timing of satisfaction, period
Federal Solution Segment \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,207,900
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Federal Solution Segment \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 451,278
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Federal Solution Segment \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 176,103
Revenue, remaining performance obligation, expected timing of satisfaction, period
Critical Infrastructure \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,634,625
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Critical Infrastructure \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 632,273
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Critical Infrastructure \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 859,966
Revenue, remaining performance obligation, expected timing of satisfaction, period