PAE (PAE) 10-K 16 Mar 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 09, 2021	Jun. 28, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-38643
Entity Registrant Name	PAE INCORPORATED
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3173473
Entity Address, Address Line One	7799 Leesburg Pike
Entity Address, Address Line Two	Suite 300 North
Entity Address, City or Town	Falls Church
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22043
City Area Code	703
Local Phone Number	717-6000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 641,171,952
Entity Common Stock, Shares Outstanding		93,069,815
Documents Incorporated by Reference	Portions of the definitive proxy statement relating to the registrant’s annual meeting of stockholders are incorporated by reference in response to Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K.
Entity Central Index Key	0001720821
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Class A Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Class A Common Stock
Trading Symbol	PAE
Security Exchange Name	NASDAQ
Warrants
Entity Information [Line Items]
Title of 12(b) Security	Warrants
Trading Symbol	PAEWW
Security Exchange Name	NASDAQ

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues	$ 2,714,628	$ 2,763,893	$ 2,608,562
Cost of revenues	2,098,153	2,183,574	1,991,622
Selling, general and administrative expenses	498,827	530,080	536,019
Amortization of intangible assets	34,154	33,205	35,780
Total operating expenses	2,631,134	2,746,859	2,563,421
Program profit	83,494	17,034	45,141
Other income, net	7,272	9,785	4,980
Operating income	90,766	26,819	50,121
Interest expense, net	(73,857)	(86,011)	(84,360)
Income (loss) before income taxes	16,909	(59,192)	(34,239)
Expense (benefit) from income taxes	3,083	(9,131)	(2,661)
Net income (loss)	13,826	(50,061)	(31,578)
Noncontrolling interest in earnings of ventures	(1,464)	(252)	2,881
Net income (loss)	$ 15,290	$ (49,809)	$ (34,459)
Net income (loss) per share attributed to PAE Incorporated:
Basic (in dollars per share)	$ 0.18	$ (2.36)	$ (1.63)
Diluted (in dollars per share)	$ 0.18	$ (2.36)	$ (1.63)
Weighted average shares outstanding:
Basic (in shares)	84,114,016	21,127,823	21,127,823
Diluted (in shares)	85,369,328	21,127,823	21,127,823

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 13,826	$ (50,061)	$ (31,578)
Other comprehensive income (loss):
Change in foreign currency translation adjustment, net of tax	1,583	317	(1,061)
Other, net	427	1,687	1,686
Other comprehensive income	2,010	2,004	625
Comprehensive income (loss)	15,836	(48,057)	(30,953)
Comprehensive (loss) income attributed to noncontrolling interests	(1,084)	(178)	2,656
Comprehensive income (loss) attributed to PAE Incorporated	$ 16,920	$ (47,879)	$ (33,609)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 85,908	$ 68,035
Accounts receivable, net	585,511	442,180
Prepaid expenses and other current assets	61,607	43,549
Total current assets	733,026	553,764
Property and equipment, net	27,615	30,404
Deferred income taxes, net	0	3,212
Investments	18,272	17,925
Goodwill	590,668	409,588
Intangible assets, net	258,210	180,464
Operating lease right-of-use assets, net	191,370	162,184
Other noncurrent assets	10,209	13,758
Total assets	1,829,370	1,371,299
Current liabilities:
Accounts payable	152,962	124,661
Accrued expenses	114,222	102,315
Customer advances and billings in excess of costs	106,475	51,439
Salaries, benefits and payroll taxes	145,186	130,633
Accrued taxes	15,582	18,488
Current portion of long-term debt, net	5,961	22,007
Operating lease liabilities, current portion	46,756	36,997
Other current liabilities	45,037	30,893
Total current liabilities	632,181	517,433
Deferred income taxes, net	4,389	0
Long-term debt, net	860,306	727,930
Long-term operating lease liabilities	145,569	129,244
Other long-term liabilities	30,273	8,601
Total liabilities	1,672,718	1,383,208
Stockholders’ equity:
Preferred stock, $0.0001 par value per share, 1,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value per share: 210,000,000 shares authorized; 92,040,654 and 21,127,823 shares issued and outstanding as of December 31, 2020 and December 31, 2019, respectively	9	3
Additional paid-in capital	252,612	101,742
Accumulated deficit	(130,081)	(145,371)
Accumulated other comprehensive income (loss)	1,876	(134)
Total PAE Incorporated stockholders' equity	124,416	(43,760)
Noncontrolling interests	32,236	31,851
Total liabilities and equity	$ 1,829,370	$ 1,371,299

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock authorized (in shares)	1,000,000	1,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock authorized (in shares)	210,000,000	210,000,000
Common stock issued (in shares)	92,040,654	21,127,823
Common stock outstanding (in shares)	92,040,654	21,127,823

Consolidated Statements of Stoc

Consolidated Statements of Stockholders Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Previously Reported	Restatement Adjustment	Total PAE Incorporated Stockholders’ Equity	Total PAE Incorporated Stockholders’ EquityCumulative Effect, Period of Adoption, Adjustment	Total PAE Incorporated Stockholders’ EquityPreviously Reported	Common Stock	Common StockPreviously Reported	Common StockRestatement Adjustment	Additional Paid-in Capital	Additional Paid-in CapitalPreviously Reported	Additional Paid-in CapitalRestatement Adjustment	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment	Accumulated DeficitPreviously Reported	Accumulated Other Comprehensive (Loss) / Income	Accumulated Other Comprehensive (Loss) / IncomePreviously Reported	Noncontrolling Interests	Noncontrolling InterestsCumulative Effect, Period of Adoption, Adjustment	Noncontrolling InterestsPreviously Reported
Beginning balance at Dec. 31, 2017	$ 66,439	$ (1,195)			$ 37,734	$ 145		$ 3			$ 101,742			$ (61,248)	$ 145		$ (2,763)		$ 28,705	$ (1,340)
Beginning balance (in shares) at Dec. 31, 2017								282,047,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(31,578)				(34,459)									(34,459)					2,881
Other comprehensive income, net	625				625												625
Distributions to venture partners and other	(2,806)																		(2,806)
Ending balance at Dec. 31, 2018	31,485		$ 31,485	$ 0	4,045		$ 4,045	$ 2	$ 3	$ (1)	101,743	$ 101,742	$ 1	(95,562)		$ (95,562)	(2,138)	$ (2,138)	27,440		$ 27,440
Ending balance (in shares) at Dec. 31, 2018								21,127,823,000	282,047,000	20,845,776,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(50,061)				(49,809)									(49,809)					(252)
Other comprehensive income, net	2,004				2,004												2,004
Distributions to venture partners and other	(742)																		(742)
Equity contributions from venture partners	5,405																		5,405
Ending balance at Dec. 31, 2019	$ (11,909)				(43,760)			$ 2			101,743			(145,371)			(134)		31,851
Ending balance (in shares) at Dec. 31, 2019	21,127,823							21,127,823,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	$ 13,826				15,290									15,290					(1,464)
Other comprehensive income, net	2,010				2,010												2,010
Distributions to venture partners and other	(291)																		(291)
Equity contributions from venture partners	2,140																		2,140
Private placement	220,000				220,000			$ 2			219,998
Private placement (in shares)								23,913,044,000
Equity infusion from Gores	364,778				364,778			$ 5			364,773
Equity infusion from Gores (in shares)								46,999,787,000
Payment to Shay Stockholders	(446,845)				(446,845)						(446,845)
Stock-based compensation	12,943				12,943						12,943
Ending balance at Dec. 31, 2020	$ 156,652				$ 124,416			$ 9			$ 252,612			$ (130,081)			$ 1,876		$ 32,236
Ending balance (in shares) at Dec. 31, 2020	92,040,654							92,040,654,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net income (loss)	$ 13,826	$ (50,061)	$ (31,578)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of property and equipment	9,484	12,875	14,459
Amortization of intangible assets	34,154	33,205	33,817
Amortization of debt issuance cost	6,690	8,092	8,382
Loss on extinguishment of debt	16,528	0	0
Stock-based compensation	12,943	0	0
Net undistributed (loss) income from unconsolidated ventures	(6,504)	(2,680)	180
Deferred income taxes, net	(19,278)	(17,247)	(14,801)
Other non-cash activities, net	383	36,942	380
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable, net	(54,345)	74,416	(101,178)
Accounts payable	(4,529)	618	35,404
Accrued expenses	9,529	(5,629)	12,058
Customer advances and billings in excess of costs	48,618	23,569	(15,004)
Salaries, benefits and payroll taxes	554	17,411	7,510
Prepaid expenses and other current assets	(5,862)	3,202	355
Other current and noncurrent liabilities	39,215	(25,220)	(8,628)
Investments	6,538	6,102	12,973
Other noncurrent assets	(4,141)	1,450	(688)
Accrued taxes	(2,941)	(397)	(10,482)
Net cash provided by (used in) operating activities	100,862	116,648	(56,841)
Investing activities
Expenditures for property and equipment	(3,835)	(9,436)	(5,702)
Acquisition of Metis Solutions Corporation, net of acquired cash	(90,271)	0	0
Acquisition of Centra Technology Inc, net of acquired cash	(222,124)	0	0
Other investing activities, net	17	6,747	(10,849)
Net cash used in investing activities	(316,213)	(2,689)	(16,551)
Financing activities
Net contributions from noncontrolling interests	2,095	5,405	0
Borrowings on long-term debt	961,030	267,375	107,099
Repayments on short-term debt	0	0	(1,966)
Repayments on long-term debt	(843,131)	(367,312)	(69,480)
Payment of debt issuance costs	(26,646)	0	0
Recapitalization from merger with Gores III	605,713	0	0
Payment of underwriting and transaction costs	(27,267)	0	0
Distribution to selling stockholders	(439,719)	0	0
Other financing activities, net	(292)	(742)	(2,806)
Net cash provided by (used in) financing activities	231,783	(95,274)	32,847
Effect of exchange rate changes on cash and cash equivalents	1,441	(1,747)	(1,940)
Net increase (decrease) in cash and cash equivalents	17,873	16,938	(42,485)
Cash and cash equivalents at beginning of period	68,035	51,097	93,582
Cash and cash equivalents at end of period	85,908	68,035	51,097
Supplemental cash flow information
Cash paid for interest	45,247	78,019	74,579
Cash paid for taxes	$ 10,936	$ 9,552	$ 19,093

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business PAE Incorporated, formerly known as Gores Holdings III, Inc. (“Gores III”), was originally incorporated in Delaware on October 23, 2017 as a special purpose acquisition company formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization, or other similar business combination with one or more target businesses. On September 11, 2018, Gores III consummated its initial public offering (the “IPO”), following which our shares began trading on the Nasdaq Stock Market (“Nasdaq”). Unless the context otherwise indicates, references herein to the “Company" or “PAE” refer to PAE Incorporated and its consolidated subsidiaries. On February 10, 2020 (the “Closing Date”), the Company completed the previously announced business combination (the “Business Combination”) in which Shay Holding Corporation (“Shay”) was acquired by Gores III. The transaction was completed in a multi-step process pursuant to which Shay ultimately merged with and into a wholly-owned subsidiary of Gores III, with the Gores III subsidiary continuing as the surviving company. As a result of the Business Combination, each share of common stock of Shay was cancelled and converted into the right to receive a portion of the consideration payable in connection with the transaction and Gores III acquired Shay (as it existed immediately prior to the Second Merger, as such term is defined in the Merger Agreement) and its subsidiaries. Additionally, the stockholders of Shay as of immediately prior to the transaction hold a portion of the common stock of the Company. For accounting purposes, the Business Combination is treated as a reverse acquisition and recapitalization (the “Recapitalization”), in which Shay is considered the accounting acquirer (and legal acquiree) and Gores III is considered the accounting acquiree (and legal acquirer). Accordingly, as of the Closing Date, Shay’s historical results of operations replaced Gores III’s historical results of operations for periods prior to the Business Combination and the results of operations of both companies are included in the accompanying consolidated financial statements for periods following the Closing Date. See Note 6 - “Business Combinations and Acquisitions” for additional information. PAE provides a wide variety of integrated support solutions, including defense and military readiness, diplomacy, intelligence support, business process outsourcing, counter-terrorism solutions, peacekeeping, development, host nation capacity building, aircraft and ground equipment maintenance and logistics, and operations and maintenance of facilities and infrastructure. Customers include agencies of the U.S. Government, such as the Department of Defense (“DoD”) and Department of State (“DoS”), the National Aeronautics and Space Administration (“NASA”), Department of Homeland Security, intelligence community agencies and other civilian agencies, as well as allied foreign governments and international organizations. The Company’s operations are currently organized into the following two reportable segments: • Global Mission Services (“GMS”): GMS provides infrastructure and logistics management, international logistics and stabilization support, and aircraft and vehicle readiness and sustainment support. The segment focuses on customer relationships with DoD, DoS, NASA, and other government agencies for work both in the United States and outside of the United States. • National Security Solutions (“NSS”): NSS provides counter-threat solutions, business process outsourcing, adjudication support services and full life cycle support for complex legal matters. NSS focuses on customer relationships in the areas of intelligence, defense and security, and with civilian agencies. The Company separately presents the costs associated with certain corporate functions as “Corporate”, which primarily include costs that are not reimbursed by the Company’s U.S. Government customers.

Significant Accounting Principl

Significant Accounting Principles and Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Principles and Policies	Significant Accounting Principles and Policies Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) for annual financial information. In management’s opinion, all adjustments, consisting of only normal recurring adjustments, considered necessary for a fair presentation have been included. The Company closes its books and records on the last Sunday of the calendar quarter to align its financial closing with its business process. This practice only affects interim periods, as the Company’s fiscal year ends on December 31, and therefore the closing of books and records for the year ends reflected in this Annual Report on Form 10-K were December 31, 2020 and December 31, 2019 and December 31, 2018, respectively. The consolidated financial statements and disclosures included herein are labeled based on that convention. The consolidated financial statements include the accounts of PAE Incorporated and subsidiaries and ventures in which the Company owns more than 50% or otherwise controls. All intercompany amounts have been eliminated in consolidation. Use of Estimates These consolidated financial statements are prepared in conformity with U.S. GAAP, which requires the use of estimates and assumptions, including assumptions to determine the fair value of acquired assets and liabilities, recoverability of long-lived assets, goodwill, valuation allowances on deferred taxes, inputs used in stock based compensation and anticipated contract costs and revenues utilized in the earnings recognition process, which affect the reported amounts in the consolidated financial statements and accompanying notes. Due to the size and nature of many of the Company’s programs, the estimation of total revenues and cost at completion is subject to a wide range of variables, including assumptions for timing and risks. Actual results may differ from management’s estimates and changes in these estimates are recorded when known. Significant Accounting Policies Revenue Recognition As of January 1, 2018, the Company adopted Accounting Standards Codification (“ASC”) 606, Revenues From Contracts With Customers (Topic 606) using the modified retrospective method. The majority of the Company’s revenues are generated from contracts with the U.S. Government and its agencies. The Company enters into a variety of contract types, including fixed price, cost reimbursable, and time and materials contracts. The Company accounts for a contract when it has been approved by all parties in the arrangement, the rights of the parties and payment terms are identified, and collectability of the consideration is reasonably assured. At contract inception, the Company identifies distinct goods or services promised in the contract, referred to as performance obligations, and then determines the transaction price for the contract. The transaction price can be a fixed or variable amount, and contracts can contain award fees, incentive fees or other provisions that can either increase or decrease the transaction price. These variable amounts generally are awarded upon achievement of certain performance metrics, program milestones or cost targets and can be based upon customer discretion. The Company estimates variable consideration at the most likely amount to which it expects to be entitled. Estimated amounts of variable consideration are included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with all variable consideration is resolved or recognized. The Company’s estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of anticipated performance and historical, current and forecasted information that is reasonably available. The Company’s contracts contain promises to provide distinct goods or services to its customers. These represent separate performance obligations and units of account. Management evaluates whether a single contract should be accounted for as more than one performance obligation or whether two or more contracts should be combined and accounted for as one single arrangement at the outset of the contract. Most of the Company’s contracts consist of providing a complex set of interrelated goods and services that together provide a single deliverable or solution to the customer, and accordingly are accounted for as a single performance obligation. The Company also may engage with a customer on a contract that contains multiple distinct goods or services. In such circumstance, multiple performance obligations exist, and the Company allocates the contract’s transaction price to the individual performance obligations based on estimated relative standalone selling price. The primary method used to estimate standalone selling price is the expected cost plus a margin approach, under which the Company forecasts expected costs of satisfying a performance obligation and then adds an appropriate margin for that distinct good or service promised. Revenue is recognized when, or as, the performance obligation is satisfied. For substantially all of the Company’s contracts, the Company satisfies its performance obligations over time as the Company’s customer simultaneously receives and consumes benefits. In such instances, revenue is recognized over time when transfer of control to the customer occurs. For U.S. Government contracts, this ongoing obligation to deliver goods or services is supported by clauses in the contract that allow the U.S. Government to unilaterally terminate the contract for convenience, pay for costs incurred plus a reasonable profit and take control of any work in process. When a transfer of control occurs over time, revenue is recognized based on the extent of progress towards completion of the performance obligation. Based on the nature of the products and services provided in the contract, the Company uses judgment to determine if an input measure or output measure best depicts the transfer of control over time. For services contracts, performance obligations are typically satisfied as services are rendered and the Company uses a contract cost-based input method to measure progress. Contract costs include labor, material and allocable indirect expenses. Revenue is recognized proportionally as contract costs are incurred plus estimated fees. If a contract does not meet the criteria for recognizing revenue over time, revenue is recognized at the point in time when control of the good or service is transferred to the customer. Control is considered to have transferred when the customer has legal title and the Company has a right to payment. Contracts are often modified to account for changes in contract specifications and requirements. Contract modifications impact a performance obligation when the modification either creates new, or changes the existing, enforceable rights and obligations. The effect of a contract modification on the transaction price and the measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue under the cumulative catch-up method. Significant changes in one or more estimates could affect the profitability of a contract. Adjustments are recognized in estimated profit on contracts in the period identified. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, the Company recognizes that loss in the period it is identified. Management reviews the progress and execution of performance obligations under the estimate at completion process. As part of this process, management reviews information including, but not limited to, key contract terms and conditions, program schedule, progress towards completion, identified risks and opportunities and the related changes in estimates of revenues and costs. The risks and opportunities include management’s judgment about the ability and cost to achieve the contract milestones and other technical contract requirements. Management must make assumptions and estimates regarding labor productivity and availability, the complexity of the work to be performed, the availability of materials, the length of time to complete the performance obligation, execution by subcontractors, the availability and timing of funding from customers and overhead cost rates, among other variables. A significant change in one or more of these estimates could affect the profitability of the Company’s contracts. Operating Expenses Operating expenses include all cost of revenues, selling, general and administrative expenses, amortization of intangible assets, and depreciation of fixed assets. Cost of revenues includes costs related to labor, material, subcontract labor and other costs that are allowable and allocable to contracts under federal procurement standards. Selling, general and administrative expenses primarily consist of (i) fringe benefits related to the contract costs; (ii) salaries and wages plus associated fringe benefits and occupancy costs related to executive and senior management, business development, bid and proposal, contracts administration, finance and accounting, human resources, recruiting, information systems support, legal and corporate governance; and (iii) unallowable costs under applicable procurement standards that are not allocable to contracts for billing purposes. Unallowable costs do not generate revenue, but are necessary for business operations. Cash and Cash Equivalents The Company considers cash on deposit and all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. The Company does not maintain any restricted cash. Accounts Receivable, net Amounts billed and due from customers are recorded as billed receivables within accounts receivable, net on the consolidated balance sheets. Generally, customer accounts are due within 30 to 45 days of billings. The Company recognizes an allowance for credit losses based on historical experience, current conditions and reasonable and supportable forecasts. The Company assesses its overall allowance for credit losses at least on a quarterly basis. Prior to the implementation of Accounting Standards Update (“ASU”) 2016-13 “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”), the Company recorded adjustments to an allowance for doubtful accounts when collectability was uncertain. For further information on the effect of adoption of ASU 2016-13, refer to Note 3 – “Recent Accounting Pronouncements – Accounting Pronouncements Adopted”. Contract Assets Contract assets primarily consist of unbilled receivables which represent rights to payment for work or services completed but not billed as of the reporting date. Contract assets are classified as unbilled receivables within accounts receivable, net on the consolidated balance sheets. Contract Liabilities Contract liabilities are advances and milestone payments from customers on certain contracts that exceed revenue earned to date. Contract liabilities are reported as customer advances and billings in excess of costs on the consolidated balance sheets. Concentration of Credit Risk The Company’s receivables are highly concentrated with agencies of the U.S. Government. Approximately 91.4% and 96.0% of receivables as of December 31, 2020 and 2019, respectively, were generated from contracts with the U.S. Government. Approximately 90.0% and 93.0% of revenues for the years ended December 31, 2020 and 2019, respectively, were related to contracts with the U.S. Government. The Company believes that credit risk related to its accounts receivable is limited due to a large number of customers in differing segments and agencies of the U.S. Government, as well as the creditworthiness of the U.S. Government. Property and Equipment Property and equipment are recorded at cost. The Company calculates depreciation and amortization using a straight-line method over the estimated useful lives of assets. The estimated useful life of machinery and equipment is 4 to 20 years, computer software and equipment is 3 to 7 years, transportation equipment is 4 to 11 years, furniture and fixtures is 5 to 12 years, and leasehold improvements is 3 to 16 years. Goodwill Goodwill represents the excess of the fair value of consideration transferred, plus the fair value of any non-controlling interests in the acquiree, over the fair value of the net assets acquired and liabilities assumed as of the acquisition date. Goodwill is not amortized, but instead is tested annually for impairment at the reporting unit level and tested more frequently if events or circumstances indicate that the carrying value may not be recoverable. The Company’s policy is to perform its annual goodwill impairment evaluation as of the first day of the fourth quarter of its fiscal year. The Company may first assess qualitative factors to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount or elect to bypass such assessment. If it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, or the Company elects to bypass such assessment, the Company then determines the fair value of each reporting unit quantitatively. The fair value of each reporting unit is compared to the carrying amount of the reporting unit. If the carrying amount of the reporting unit exceeds the fair value, then an impairment loss is recognized for the difference. The results of the Company’s annual goodwill impairment test for 2020, 2019 and 2018 indicated that no impairment existed. See Note 9 - “Goodwill and Intangible Assets” for additional information. The evaluation includes comparing the fair value of each of the reporting units using a discounted cash flow methodology, or other fair value measures as considered appropriate in the circumstances, to its net book value, including goodwill. If the net book value exceeds the fair value, the Company will measure impairment by comparing the derived fair value of goodwill to its carrying value, and any impairment is recorded in the current period. Intangible Assets Intangible assets consist of customer relationships, technology and trade name and are recognized at their estimated fair values at the date of acquisition. The Company amortizes intangible assets using an accelerated method that best approximates the proportion of the future cash flows estimated to be generated in each period over the estimated useful lives of the applicable assets. On an annual basis, the Company evaluates this method to ensure continued appropriateness unless the estimated useful lives are determined to be indefinite or the estimated cash flows indicate another pattern of amortization should be used. The Company amortizes acquired intangibles over the following periods: Customer relationships 6-13 years Technology 3-5 years Trade name 5-10 years Impairment of Certain Long-Lived Assets The Company reviews the carrying values of long-lived assets other than goodwill for impairment if events or changes in the facts and circumstances indicate that their carrying values may not be recoverable. The Company assesses impairment by comparing the estimated undiscounted future cash flows of the related assets to the carrying value. If an asset is determined to be impaired, the Company would recognize an impairment charge in the current period for the difference between the fair value of the asset and the carrying amount. For the years ended December 31, 2020, 2019 and 2018, there was no impairment of long-lived assets. Leases The Company adopted ASC 842, Leases (Topic 842) effective January 1, 2019, which changed the way the Company accounts for its leases. The Company’s leases are generally for facilities and office space and are classified as operating leases. A contract is determined to be a leasing arrangement at inception. A right-of-use (“ROU”) asset represents the right to control the use of an identified asset over the lease term and a lease liability represents the obligation to make lease payments arising from the lease. If a lease arrangement is determined to exist, a ROU asset and corresponding lease liability are recorded on the balance sheet at the lease commencement date based on the present value of lease payments over the lease term. The Company uses the incremental borrowing rate on the lease commencement date to determine the present value of lease payments. Operating lease expenses for the Company’s operating leases are recognized on a straight-line basis over the lease term. Certain operating leases may contain renewal or termination options that are reasonably certain of exercise. Lease and non-lease components are accounted for together as a single lease component for operating leases. The Company’s leases may also include variable lease payments, such as for insurance and taxes, which are not included in measuring ROU assets and lease liabilities and are recorded as variable lease expense in the period incurred. Payments for maintenance costs, utilities, or other variable payments that pertain to non-lease components are expensed as incurred and not reflected in the ROU assets and lease liabilities. Segment Reporting The Company’s operations and reportable segments are organized around the nature of the products and services provided to customers. The Company defines its reportable segments based on the way the chief operating decision maker (“CODM”), currently its President and Chief Executive Officer, manages the operations of the Company for purposes of allocating resources and assessing performance. Although information regarding certain capabilities and markets served may be discussed for purposes of promoting an understanding of the business, the Company manages its business and allocates resources based on the two segments. The Company separately presents the costs associated with certain corporate functions as Corporate, which primarily include costs that are not reimbursed by the Company’s U.S. Government customers. Consolidated Investments and Equity Method Investments The Company consolidates an investment when it has determined that the investment is a variable interest entity (“VIE”) and that the Company is the primary beneficiary. This determination is made at the inception of the Company’s involvement with the investment, in accordance with U.S. GAAP, and is reevaluated when facts and circumstances change. The Company considers both qualitative and quantitative factors to form a conclusion as to whether it, or another interest holder, has the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance. The Company also considers qualitative and quantitative factors to determine if it, or another interest holder, has the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. The Company also consolidates ventures that are not VIEs when it has a controlling interest. When the Company consolidates an entity that is not wholly owned, the Company records the minority interests in the entity as a component of non-controlling interests in the stockholders’ equity section of the consolidated balance sheets. The Company has included the non-controlling interest in earnings of ventures within the consolidated net income and deducted the same amount to derive net income attributable to the Company. Other investments are accounted for under the equity method of accounting. These investments consist of ventures determined to be VIEs when the Company is not deemed to be the primary beneficiary and ventures that are not VIEs that the Company accounts for under the voting interest model when the Company has significant influence but not control. Significant influence generally is presumed to exist when the Company’s ownership in the investee is 20% or greater, unless other factors indicate otherwise. Under the equity method of accounting, the Company’s share of the net earnings or losses of the investee is included in other income, net on the accompanying consolidated statements of operations. The aggregate carrying amount of certain investments in equity investees exceeded the underlying equity in their net assets. The amount in excess of carrying amount is amortized using an accelerated method that best approximates the proportion of the future cash flows estimated to be generated in each period over the remaining life of the contracts performed by the equity investees. The Company evaluates the equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amount of such investments may not be recoverable. If a decline in the value of an equity method investment is determined to be other than temporary, a loss is recorded in earnings in the current period. For the years ended December 31, 2020, 2019 and 2018, the Company did not record an impairment of equity method investments. Stock-Based Compensation Compensation expense for stock-based awards to employees that vest over a specific service period, is recognized in the consolidated statements of operations based on their grant date fair value and straight-line over the vesting period of the awards. For stock-based awards that vest based on the achievement of related performance conditions, compensation expense is recognized based on the expected achievement of the related performance conditions at the end of each reporting period over the vesting period of the award. If the Company’s initial estimates of the achievement of the performance conditions change, the related stock-based compensation expense and timing may fluctuate from period to period based on those estimates. If the performance conditions are not met, no stock-based compensation expense will be recognized, and any previously recognized stock-based compensation expense will be reversed. Forfeitures are recognized in compensation costs when those occur. Foreign Currency Translation The assets and liabilities of the Company’s foreign subsidiaries whose functional currency is other than the U.S. dollar are translated at the exchange rate in effect on the reporting date, while income and expenses are translated at the weighted-average exchange rate during the period. The Company’s primary practice is to negotiate contracts in the same currency in which the predominant expenses are incurred, thereby mitigating the exposure to foreign currency fluctuations. The net translation gains and losses are not included in determining net income, but are accumulated as a separate component of equity. Foreign currency transaction gains and losses are included in other income, net in the accompanying consolidated statements of operations. Income Taxes The Company accounts for income taxes under the asset and liability method in accordance with the accounting standard for income taxes. The asset and liability method requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities. Under this method, changes in tax rates and laws are recognized in income in the period such changes are enacted. The Company records net deferred tax assets to the extent that it believes these assets will more likely than not be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent results of operations. If the Company determines that it will be able to realize its deferred income tax assets in the future in excess of their net recorded amount or will no longer be able to realize its deferred income tax assets in the future as currently recorded, the Company makes an adjustment to the valuation allowance that will decrease or increase, respectively the provision for income taxes. The provision for federal, state, foreign and local income taxes is calculated on income before income taxes based on current tax law and includes the cumulative effect of any changes in tax rates from those used previously in determining deferred tax assets and liabilities. Such provision differs from the amounts currently payable because certain items of income and expense are recognized in different reporting periods for financial reporting purposes than for income tax purposes. The Company recognizes liabilities for uncertain tax positions when it is more likely than not that a tax position will not be sustained upon examination and settlement with various taxing authorities. Liabilities for uncertain tax positions are determined based upon the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company recognizes interest and penalties related to uncertain tax positions in its income tax expense (benefit) on the consolidated statements of operations. For further discussion on uncertain tax positions which were settled for amounts different than recorded amounts see Note 21 - “Income Taxes”. Comprehensive Income (Loss) Comprehensive income (loss) is the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other comprehensive income (loss) refers to revenue, expenses, and gains and losses that, under U.S. GAAP, are included in comprehensive income (loss), but excluded from the determination of net income (loss). Foreign currency translation and pension and other post-retirement benefit adjustments are the only elements of other comprehensive income (loss) and accumulated other comprehensive income (loss). Net Income (Loss) Per Share Basic net income (loss) per common share is determined by dividing the net income (loss) allocable to stockholders by the weighted average number of common shares outstanding during the periods presented. Diluted income (loss) per share is computed by dividing the net income (loss) allocable to common stockholders by the weighted average number of shares of common stock and common stock equivalents outstanding for the dilutive effect of common stock equivalents for the period. Fair Value of Financial Instruments Fair value is the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between marketplace participants at the measurement date. The valuation techniques the Company utilizes to measure the fair value of financial instruments are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect internal market assumptions. These two types of inputs create the following fair value hierarchy: • Level 1 – Quoted prices for identical instruments in observable active markets. • Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 – Significant inputs to the valuation model are unobservable and reflect Company’s own estimates and assumptions. The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, and amounts included in other current assets and current liabilities that meet the definition of a financial instrument approximate fair value because of the short-term nature of these amounts.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2020
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Pronouncements Adopted In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842 “ASU 2016-02”), which supersedes the current lease guidance under ASC 840 Leases (Topic 840). Management adopted ASU 2016-02 on January 1, 2019, electing to use the package of practical expedients permitted under the transition guidance that allows for the carry forward of historical lease classification for existing leases on the adoption date and does not require the assessment of existing lease contracts to determine whether the contracts contain a lease or initial direct costs. Prior periods were not retrospectively adjusted. The adoption of this standard resulted in the recognition of ROU assets and lease liabilities for operating leases on the consolidated balance sheet. There was no cumulative impact to retained earnings and the January 1, 2019 adoption of ASC 842 did not have a material impact to either the consolidated statements of operations or cash flows. In June 2016, the FASB issued Accounting Standards Update ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses for Financial Instruments, which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost, replacing the existing incurred loss impairment model. The new standard is effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted this guidance effective January 1, 2020 under the modified retrospective method and such adoption did not have a material impact on the Company’s financial statements. In August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Topic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract, which requires the tracking and recognition of costs that will be capitalized as an asset and amortized over the assets useful life. The new standard is effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted this guidance effective January 1, 2020 prospectively and the standard did not have a material impact on the Company’s financial statements. Accounting Pronouncements Not Yet Adopted

Revenues

Revenues	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenues	Revenues Disaggregated Revenues Disaggregated revenues by customer type were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total DoD $ 807,722 $ 277,134 $ 1,084,856 Other U.S. government agencies 1,079,345 264,185 1,343,530 Commercial and non-U.S. customers 193,407 92,835 286,242 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total DoD $ 858,623 $ 222,978 $ 1,081,601 Other U.S. government agencies 1,123,459 359,681 1,483,140 Commercial and non-U.S. customers 117,655 81,497 199,152 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total DoD $ 784,532 $ 205,404 $ 989,936 Other U.S. government agencies 1,096,193 359,977 1,456,170 Commercial and non-U.S. customers 88,118 74,338 162,456 Total $ 1,968,843 $ 639,719 $ 2,608,562 Revenues by contract type were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total Cost-reimbursable $ 1,182,865 $ 166,026 $ 1,348,891 Fixed-price 676,714 269,530 946,244 Time and materials 220,895 198,598 419,493 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total Cost-reimbursable $ 1,206,710 $ 105,360 $ 1,312,070 Fixed-price 717,595 286,366 1,003,961 Time and materials 175,432 272,430 447,862 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total Cost-reimbursable $ 1,229,707 $ 90,061 $ 1,319,768 Fixed-price 595,127 281,859 876,986 Time and materials 144,009 267,799 411,808 Total $ 1,968,843 $ 639,719 $ 2,608,562 Disaggregated revenues by geographic location were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total United States $ 1,104,536 $ 626,961 $ 1,731,497 International 975,938 7,193 983,131 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total United States $ 1,090,765 $ 657,706 $ 1,748,471 International 1,008,972 6,450 1,015,422 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total United States $ 1,013,830 $ 635,158 $ 1,648,988 International 955,013 4,561 959,574 Total $ 1,968,843 $ 639,719 $ 2,608,562 Remaining Performance Obligations The Company’s remaining performance obligations balance represents the expected revenue to be recognized for the satisfaction of remaining performance obligations on existing contracts. This balance excludes unexercised contract option years and task orders that may be issued underneath an indefinite delivery, indefinite quantity contract. The remaining performance obligations balance as of December 31, 2020 and December 31, 2019 was $1,722.0 million and $1,640.0 million, respectively. As of December 31, 2020, the Company expects to recognize approximately 95.4% and 4.6% of the remaining performance obligations balance as revenue over the next year and thereafter, respectively. Contract assets consist of unbilled receivables, which represent rights to payment for work or services completed but not billed as of the reporting date. Contract assets are recorded as unbilled receivables within accounts receivable, net on the consolidated balance sheets. Contract liabilities are advances and milestone payments from customers on certain contracts that exceed revenue earned to date. Contract liabilities are recorded as customer advances and billings in excess of costs on the consolidated balance sheets. Contract assets and contract liabilities consisted of the following as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 Contract assets $ 360,552 $ 295,103 Contract liabilities $ 106,475 $ 51,439 The increase in contract assets of $65.4 million for the year ended December 31, 2020 was primarily due to the timing of billings, partially offset by revenue recognized related to the satisfaction of performance obligations and Metis and CENTRA contract asset balances added in the fourth quarter. The increase in contract liabilities of $55.0 million for the year ended December 31, 2020 was primarily due to the timing of advance payments from customers and Metis and CENTRA contract liabilities balance added in the fourth quarter partially offset by revenue recognized during the period.

Contract Assets and Contract Li

Contract Assets and Contract Liabilities	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Contract Assets and Contract Liabilities	Revenues Disaggregated Revenues Disaggregated revenues by customer type were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total DoD $ 807,722 $ 277,134 $ 1,084,856 Other U.S. government agencies 1,079,345 264,185 1,343,530 Commercial and non-U.S. customers 193,407 92,835 286,242 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total DoD $ 858,623 $ 222,978 $ 1,081,601 Other U.S. government agencies 1,123,459 359,681 1,483,140 Commercial and non-U.S. customers 117,655 81,497 199,152 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total DoD $ 784,532 $ 205,404 $ 989,936 Other U.S. government agencies 1,096,193 359,977 1,456,170 Commercial and non-U.S. customers 88,118 74,338 162,456 Total $ 1,968,843 $ 639,719 $ 2,608,562 Revenues by contract type were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total Cost-reimbursable $ 1,182,865 $ 166,026 $ 1,348,891 Fixed-price 676,714 269,530 946,244 Time and materials 220,895 198,598 419,493 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total Cost-reimbursable $ 1,206,710 $ 105,360 $ 1,312,070 Fixed-price 717,595 286,366 1,003,961 Time and materials 175,432 272,430 447,862 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total Cost-reimbursable $ 1,229,707 $ 90,061 $ 1,319,768 Fixed-price 595,127 281,859 876,986 Time and materials 144,009 267,799 411,808 Total $ 1,968,843 $ 639,719 $ 2,608,562 Disaggregated revenues by geographic location were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total United States $ 1,104,536 $ 626,961 $ 1,731,497 International 975,938 7,193 983,131 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total United States $ 1,090,765 $ 657,706 $ 1,748,471 International 1,008,972 6,450 1,015,422 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total United States $ 1,013,830 $ 635,158 $ 1,648,988 International 955,013 4,561 959,574 Total $ 1,968,843 $ 639,719 $ 2,608,562 Remaining Performance Obligations The Company’s remaining performance obligations balance represents the expected revenue to be recognized for the satisfaction of remaining performance obligations on existing contracts. This balance excludes unexercised contract option years and task orders that may be issued underneath an indefinite delivery, indefinite quantity contract. The remaining performance obligations balance as of December 31, 2020 and December 31, 2019 was $1,722.0 million and $1,640.0 million, respectively. As of December 31, 2020, the Company expects to recognize approximately 95.4% and 4.6% of the remaining performance obligations balance as revenue over the next year and thereafter, respectively. Contract assets consist of unbilled receivables, which represent rights to payment for work or services completed but not billed as of the reporting date. Contract assets are recorded as unbilled receivables within accounts receivable, net on the consolidated balance sheets. Contract liabilities are advances and milestone payments from customers on certain contracts that exceed revenue earned to date. Contract liabilities are recorded as customer advances and billings in excess of costs on the consolidated balance sheets. Contract assets and contract liabilities consisted of the following as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 Contract assets $ 360,552 $ 295,103 Contract liabilities $ 106,475 $ 51,439 The increase in contract assets of $65.4 million for the year ended December 31, 2020 was primarily due to the timing of billings, partially offset by revenue recognized related to the satisfaction of performance obligations and Metis and CENTRA contract asset balances added in the fourth quarter. The increase in contract liabilities of $55.0 million for the year ended December 31, 2020 was primarily due to the timing of advance payments from customers and Metis and CENTRA contract liabilities balance added in the fourth quarter partially offset by revenue recognized during the period.

Business Combinations and Acqui

Business Combinations and Acquisitions	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Business Combinations and Acquisitions	Business Combinations and Acquisitions As described in Note 1 - “Description of Business,” the Business Combination was consummated on February 10, 2020. For financial accounting and reporting purposes under U.S. GAAP, the Business Combination was accounted for as a reverse acquisition and recapitalization, with no goodwill or other intangible asset recorded. Under this method of accounting, Gores III (legal acquirer) is treated as the acquired entity and Shay (legal acquiree) is deemed to have issued common stock for the net assets and equity of Gores III consisting of mainly cash, accompanied simultaneously by the Recapitalization. The net assets of Gores III are stated at historical cost, and accordingly the equity and net assets of Shay have not been adjusted to fair value. Consequently, the consolidated assets, liabilities and results of operations of Shay are the historical financial statements of PAE Incorporated and the Gores III assets, liabilities and results of operations are consolidated with the assets, liabilities and results of operations of Shay beginning on the Closing Date. Shares and earnings per share information prior to the Business Combination have been retroactively restated to reflect the exchange ratio established in the Recapitalization. Other than professional fees paid to consummate the transaction, the Business Combination primarily involved the exchange of cash and equity between Gores III, Shay and the stockholders of the respective companies. The aggregate proceeds paid to the Shay Stockholders on the Closing Date was approximately $424.2 million. The remainder of the consideration paid to the Shay Stockholders consisted of 21,127,823 newly issued shares of Class A Common Stock of PAE Incorporated, par value $0.0001 per share (“Class A Common Stock”). In addition to the foregoing consideration paid on the Closing Date, former stockholders of Shay are entitled to receive additional Earn-Out Shares from PAE of up to an aggregate of 4,000,000 shares of Class A Common Stock if the price of Class A Common Stock trading on the Nasdaq exceeds certain thresholds during the five-year period following the completion of the Business Combination. See Note 13 - “Stockholders’ Equity - Earn-Out Agreement” for additional information. The Company also has certain warrants issued by Gores III that remain outstanding after the Business Combination. See Note 13 - “Stockholders’ Equity - Warrants” for further information about the warrants. In connection with the Business Combination, the Company recorded $20.9 million, net of tax as a reduction to additional paid in capital related to the transaction costs. These costs were directly attributable to the Recapitalization. During the third quarter, pursuant to the post-closing adjustment provisions contained in the Merger Agreement, the Company made a post-closing adjustment payment of $20.2 million to the Shay Stockholders. Additionally, during the third quarter, the Company paid $1.0 million to certain members of PAE management in connection with the post-closing adjustment, and such amount was recorded as compensation expense. CENTRA Technology, Inc. On November 20, 2020, the Company acquired 100% of the outstanding capital stock of CENTRA Technology, Inc. (“CENTRA”) for a consideration paid of $225.3 million, net. The results of CENTRA’s operations have been included in the Company’s consolidated financial statements since that date. This business combination expands and differentiates PAE's capabilities in intelligence analysis, communication systems integration and research and development services for intelligence and defense customers. The goodwill of $125.1 million arising from the acquisition relates primarily to revenue and cost synergies. This goodwill is not deductible for tax purposes. The total cash fair value of consideration paid for CENTRA was approximately $225.3 million. The information presented below represents the allocation of CENTRA’s purchase price to the fair value of assets acquired and liabilities assumed, as of the acquisition date, November 20, 2020. The Company has completed the purchase accounting valuation for this acquisition. However, the below values presented might be subject to change through the measurement period of one year after acquisition date. The major classes of assets and liabilities to which the purchase price was allocated were as follows: (in thousands) Fair Value Cash and cash equivalents $ 3,202 Accounts receivable 72,636 Prepaid expenses and other current assets 3,454 Property and equipment 2,848 Operating lease right-of-use assets 21,137 Intangible assets 74,100 Total assets acquired 177,377 Accounts payable 30,212 Accrued expenses 1,159 Customer advances and billings in excess of costs 2,965 Salaries, benefits and payroll taxes 7,969 Deferred income taxes 12,402 Operating lease liabilities, current portion 2,996 Other current liabilities 1,423 Long-term operating lease liabilities 18,038 Total liabilities assumed 77,164 Net identifiable assets acquired 100,213 Goodwill 125,113 Total estimated consideration transferred $ 225,326 Intangible assets acquired were as follows: (in thousands, except years) Weighted-average Amortization Period Fair Value Customer Relationships 10 $ 71,800 Trade Name & Trademarks 7 2,300 Total intangible assets 10 $ 74,100 The intangible trade name and trademarks is based on the strong reputation that CENTRA has, through their several brands, in the government contracting industry. This trade name is necessary to win new contracts and maintain current customer relationships. The trade name and trademark intangible was valued using the relief from royalty method, in which the value is derived from the benefit of ownership as the “relief” from royalty expense that would be incurred in the absence of ownership. The customer relationships intangible is comprised of contract backlog as of the acquisition date. Customer relationships intangible was valued using an income method approach in which the value is derived from an estimation of the after-tax cash flows specifically attributable to customer relationships. The valuation included assumptions for projections of revenue and profit margin. The amount of revenue recognized from CENTRA in the consolidated statement of operations for the year ended December 31, 2020 amounted to $31.5 million. Metis Solutions Corporation On November 23, 2020, the Company completed the acquisition of 100% of the capital stock of Metis Solutions Corporation (“Metis”) for a consideration paid of $95.7 million in cash. The results of Metis operations have been included in the consolidated financial statements since that date. This business combination expands and differentiates PAE's capabilities in intelligence analysis, training and program support for intelligence and defense customers. The goodwill of $56.0 million arising from the acquisition relates primarily to revenue and cost synergies. This goodwill is not deductible for tax purposes. The total cash fair value of consideration paid for Metis was approximately $95.7 million. The information presented below represents the allocation of Metis’ purchase price to the fair value of assets acquired and liabilities assumed, as of the acquisition date, November 23, 2020. The Company has completed the purchase accounting valuation for this acquisition. However, the below values presented might be subject to change through the measurement period of one year after acquisition date. The major classes of assets and liabilities to which the purchase price was allocated were as follows: (in thousands) Fair Value Cash and cash equivalents $ 5,469 Accounts receivable 15,905 Prepaid expenses and other current assets 621 Property and equipment 27 Operating lease right-of-use assets 599 Intangible assets 37,800 Other noncurrent assets 63 Total assets acquired 60,484 Accounts payable 2,454 Accrued expenses 1,056 Customer advances and billings in excess of costs 3,420 Salaries, benefits and payroll taxes 5,486 Deferred income taxes 7,700 Operating lease liabilities, current portion 355 Long-term operating lease liabilities 240 Total liabilities assumed 20,711 Net identifiable assets acquired 39,773 Goodwill 55,967 Total estimated consideration transferred $ 95,740 Intangible assets acquired were as follows: (in thousands, except years) Weighted-average Amortization Period Fair Value Customer Relationships 11 $ 32,200 Trade Name & Trademarks 7 5,600 Total intangible assets 10 $ 37,800 The intangible trade name and trademarks is based on the strong reputation that Metis has in the government contracting industry. This trade name is necessary to acquire new contract and further develop current service offerings. The trade name and trademarks intangible was valued using the relief from royalty method, in which the value is derived from the benefit of ownership as the “relief” from royalty expense that would be incurred in the absence of ownership. The customer relationships intangible is comprised of contract backlog as of the acquisition date. Customer relationships intangible was valued using an income method approach in which the value is derived from an estimation of the after-tax cash flows specifically attributable to customer relationships. The valuation included assumptions for projections of revenue and profit margin.

Accounts Receivable, net

Accounts Receivable, net	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Accounts Receivable, net	Accounts Receivable, net The components of Accounts receivable, net consisted of the following as of the dates presented (in thousands): December 31, December 31, 2020 2019 Billed receivables $ 227,787 $ 148,747 Unbilled receivables 360,552 295,103 Less allowance for credit losses (2,828) (1,670) Total accounts receivables, net $ 585,511 $ 442,180 As of December 31, 2020 approximately 91.4% of the Company’s accounts receivable are with the U.S. government.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net The components of property and equipment, net consisted of the following as of the dates presented (in thousands): December 31, December 31, 2020 2019 Assets not yet in service $ 2,111 $ 301 Leasehold improvements 11,906 9,823 Machinery and equipment 12,839 12,094 Computer and equipment 36,119 34,894 Transportation equipment 13,519 14,043 Furniture and fixtures 2,353 2,797 Property and equipment, gross 78,847 73,952 Less accumulated depreciation and amortization (51,232) (43,548) Total property and equipment, net $ 27,615 $ 30,404 For the year ended December 31, 2020, December 31, 2019 and December 31, 2018, depreciation expense was approximately $9.6 million, $12.9 million and $14.5 million, respectively.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, net	Goodwill and Intangible Assets, net Goodwill Based on management’s assessment of goodwill, there was no impairment or change for the year ended December 31, 2020. The Company considered the implications of COVID-19 as it relates to the fair value of goodwill. COVID-19 has had a marginally unfavorable impact on the Company’s results of operations for the year ended December 31, 2020. Since the Company’s primary customers are departments and agencies within the U.S. Government, it has not historically had significant issues collecting its receivables and management does not foresee issues collecting receivables in the foreseeable future. In addition, the Company’s contract awards typically extend to at least five years, including options, and it has a strong history of being awarded a majority of these contract options. Management does not anticipate that the pandemic will have a materially adverse impact on such options. The Company’s liquidity position has not been materially impacted, and management continues to believe that the Company has adequate liquidity to fund its operations and meet its debt service obligations for the foreseeable future. Based on management’s assessment there has been no material impact to the fair value of goodwill due to the implications of COVID-19. The following table presents changes in the carrying amount of goodwill by reportable segment for the periods presented (in thousands): GMS NSS Total Balance as of December 31, 2018 $ 208,593 $ 199,432 $ 408,025 Acquisitions — — — Other — 1,563 1,563 Balance as of December 31, 2019 $ 208,593 $ 200,995 $ 409,588 Acquisitions — 181,080 181,080 Other — — — Balance as of December 31, 2020 $ 208,593 $ 382,075 $ 590,668 Intangible Assets, net The components of intangible assets, net consisted of the following as of the dates presented (in thousands): December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 390,900 $ (149,163) $ 241,737 Technology 1,700 (1,700) — Trade name 24,800 (8,327) 16,473 Total $ 417,400 $ (159,190) $ 258,210 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 286,900 $ (116,923) $ 169,977 Technology 1,700 (1,700) — Trade name 16,900 (6,413) 10,487 Total $ 305,500 $ (125,036) $ 180,464 As of December 31, 2020, customer relationships and trade name intangibles had weighted average remaining useful lives of 8.2 years and 5.9 years, respectively. As of December 31, 2019, customer relationships and trade name intangibles had weighted average remaining useful lives of 7.9 years and 6.0 years, respectively. For the year ended December 31, 2020, December 31, 2019 and December 31, 2018, amortization expense was approximately $34.2 million, $33.2 million and $35.8 million respectively. Estimated amortization expense in future years is expected to be: As of December 31, 2020 2021 $ 50,106 2022 50,089 2023 40,666 2024 33,782 2025 28,015 Thereafter 55,552 Total $ 258,210

Consolidated Variable Interest

Consolidated Variable Interest Entities	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidated Variable Interest Entities	Consolidated Variable Interest Entities The Company is the majority shareholder and primary beneficiary of PAE (New Zealand) Limited, ATOM Training Limited, PAE-Perini LLC, Syncom Space Services LLC, PAE-SGT Partners LLC, PAE-Parsons Global Logistics Services, LLC and accordingly, these entities are consolidated. As the primary beneficiary, the Company has a risk and obligation to absorb any losses significant to the VIE and the power, through voting rights or similar rights, to direct the activities that could impact economic performance of the VIE. The use of the assets of the VIEs to settle the Company’s liabilities is subject to the approval of the managing body of each VIE. The cash flows generated by these VIEs are included within the Company’s consolidated statements of cash flows. The consolidated balance sheets include the following amounts from these consolidated VIEs as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 Assets Total assets $ 145,664 $ 127,742 Liabilities and equity Total liabilities $ 96,318 $ 80,151 Total equity 49,346 47,591 Total liabilities and equity $ 145,664 $ 127,742 The consolidated statements of operations include the following amounts from consolidated VIEs for the periods presented ( in thousands ): Year Ended December 31, December 31, December 31, 2020 2019 2018 Income statements Revenues $ 369,966 $ 340,063 $ 259,386 Cost of revenues 301,345 311,310 205,730 Selling, general and administrative expenses 73,400 80,942 84,473 Total operating expenses 374,745 392,252 290,203 Program loss (4,779) (52,189) (30,817) Other income (loss), net 908 (1,697) (1,093) Net loss $ (3,871) $ (53,886) $ (31,910)

Other current liabilities

Other current liabilities	12 Months Ended
	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Other current liabilities	Other current liabilities Other current liabilities consisted of the following as of the dates presented (in thousands): December 31, December 31, 2020 2019 Reserves $ 13,617 $ 11,659 Accrued foreign taxes 13,227 6,053 Accrued losses on contracts 11,455 11,352 Other 6,738 1,829 Total current liabilities $ 45,037 $ 30,893

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	Debt Long-term debt consisted of the following as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 First Term Loan $ 890,000 $ 506,772 Second Term Loan — 265,329 2020 ABL Credit Agreement — — Total debt 890,000 772,101 Unamortized discount and debt issuance costs (23,733) (22,164) Total debt, net of discount and debt issuance costs 866,267 749,937 Less current maturities of long-term debt (5,961) (22,007) Total long-term debt, net of current $ 860,306 $ 727,930 Credit Agreements On October 19, 2020, the Company refinanced the 2016 Credit Agreements and entered into new senior secured credit facilities (the “2020 Credit Agreements”). The Company’s new borrowing arrangement provides for borrowings up to $890.0 million. The 2020 Credit Agreements established a $740.0 million term loan facility maturing in October 2027 priced at LIBOR plus a spread of 4.5%, a $150.0 million delayed draw term loan facility maturing in October 2027 priced at LIBOR plus a spread of 4.5% (together the “First Term Loan”), and a $175.0 million senior secured revolving credit facility (“the 2020 ABL Credit Agreement”) maturing in October 2025 priced at LIBOR plus a spread of 1.8% to 2.3%. Proceeds from the debt refinance were used to pay-off the preexisting 2016 Credit Agreements first and second lien in the amount of $484.4 million and $128.8 million, respectively, with the remaining amounts to be used for general corporate purposes, mergers and acquisitions, and transaction fees and expenses. The 2016 Credit Agreements had $13.2 million in unamortized deferred financing costs and discounts on the balance sheet. The Company recognized $12.5 million as loss on extinguishment of debt in interest expense on the Consolidated Statement of Operations as the difference between the net carrying value of the extinguished debt and reacqusition price of the refinance debt. The loans under the 2020 Credit Agreements are secured by a first lien over substantially all of the Company's assets as well as affirmative and negative covenants customary for transactions of this type, including limitations with respect to indebtedness, liens, investments, dividends, disposition of assets, change in business and transactions with affiliates. The 2020 Credit Agreements require the Company to comply with specified financial covenants under certain circumstances, including the maintenance of certain leverage ratios. The 2020 Credit Agreements also contain various non-financial covenants, including affirmative covenants with respect to reporting requirements and maintenance of business activities, and negative covenants that, among other things, may limit or impose restrictions on the Company’s ability to alter the character of the business, consolidate, merge, or sell assets, incur liens or additional indebtedness, make investments, and undertake certain additional actions. PAE was in compliance with the financial covenants under the 2020 Credit Agreements as of December 31, 2020. Future principal maturities of the Company’s long-term debt are summarized as follows ( in thousands ): As of December 31, 2020 2021 $ 8,900 2022 8,900 2023 8,900 2024 8,900 2025 8,900 Thereafter 845,500 Total $ 890,000 As of December 31, 2020 and December 31, 2019, the available borrowing capacity under the 2020 ABL Credit Agreement was approximately $132.8 million and $121.8 million, respectively. Interest Rates on Credit Agreements The interest rate per annum applicable to amounts borrowed under the First Term Loan is equal to either the Base Rate (as defined below) or the LIBO Rate (as defined below), in either case, plus (i) 4.5% in the case of the Base Rate loans and (ii) 3.5% in the case of LIBO Rate loans. The “Base Rate” is defined as a fluctuating rate per annum equal to the highest of (a) the Federal Funds Rate plus one half of one percent, (b) the rate of interest in effect for such day as publicly announced from time to time by Bank of America (“BofA”) as its “prime rate,” and (c) the LIBO Rate for a LIBO Rate Term Loan with a one month interest period commencing on such day plus 1.0%. The “prime rate” is a rate set by BofA based upon various factors including BofA’s costs and desired return, general economic conditions and other factors. The LIBO Rate is defined as the rate per annum equal to the London Interbank Offered Rate or a comparable or successor rate, whichever rate is approved by the Administrative Agent (as that term is defined in the 2020 Credit Agreements). As of December 31, 2020 and December 31, 2019, the applicable interest rate on the amounts borrowed under the First Term Loan was 5.3% and 7.4%, respectively. As of December 31, 2020 and December 31, 2019, the applicable interest rate on amounts borrowed under the Second Term Loan was not applicable and 11.4%, respectively. The interest rate per annum applicable to the 2020 Credit Agreement is equal to either a Base Rate or a LIBO Rate plus (i) a range of 0.8% to 1.3% in the case of Base Rate loans and (ii) a range of 1.8% to 2.3% in the case of LIBO Rate loans, each based on average availability as of the first day of each quarter. As of December 31, 2020 and December 31, 2019, the applicable interest rate on amounts borrowed under the 2020 Revolving Credit Facility was 4.0% and 5.8%, respectively. In addition, the LIBO Rate is the subject of recent national, international, and other regulatory guidance and proposals for reform and replacement. In July 2017, the Chief Executive of the U.K. Financial Conduct Authority (the “U.K. FCA”), which regulates LIBO Rate, announced that the U.K. FCA will no longer persuade or compel banks to submit rates for the calculation of the LIBO Rate benchmark after 2021. This announcement indicates that the continuation of LIBO Rate on the current basis cannot and will not be guaranteed after 2021, and it appears likely that LIBO Rate will be discontinued or modified. The consequences of the discontinuance of the LIBO Rate benchmark cannot be entirely predicted but could include an increase in the cost of our variable rate indebtedness. Letters of Credit The Company had 13 outstanding letters of credit for program and insurance requirements totaling approximately $23.9 million as of December 31, 2020 and 11 outstanding letters of credit for program and insurance requirements totaling approximately $21.2 million as of December 31, 2019.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Authorized and Outstanding Stock In connection with the Business Combination, the Company made changes to its capital stock. The Company’s amended and restated certificate of incorporation authorizes the issuance of 211,000,000 shares of capital stock, par value of $0.0001 per share, consisting of (a) 210,000,000 shares of Class A common stock, and (b) 1,000,000 shares of preferred stock. As a result of the Business Combination, the shares issued to Shay Stockholders are reflected as if they were issued and outstanding as of the earliest reported period to reflect the new capital structure. Warrants As of December 31, 2020, there were warrants outstanding to acquire 19,999,985 shares of our Class A Common Stock including: (i) 13,333,319 warrants sold as part of the public units issued in our IPO on September 11, 2018 (the “Public Warrants”), and (ii) 6,666,666 warrants issued or transferred to our former sponsor in a private placement on the IPO closing date (the “Private Placement Warrants” and, together with the Public Warrants, the “Warrants”). The Company currently has an effective registration statement on Form S-1 relating to the issuance by the Company of up to (i) 13,333,333 shares of its Class A Common Stock issuable upon the exercise of the outstanding Public Warrants, and (ii) 6,666,666 shares of its Class A Common Stock issuable upon exercise of the Private Placement Warrants. Each whole Warrant entitles the registered holder to purchase one share of Class A Common Stock at a price of $11.50 per share. The Warrants became exercisable on March 11, 2020, thirty days following the completion of the Business Combination, and expire five years after that date, or upon redemption or liquidation. The Company may redeem outstanding Public Warrants and, unless held by the former sponsor or its permitted transferees, the Private Placement Warrants at a price of $0.01 per Warrant, provided the last reported sales price of the Company’s Class A Common Stock equals or exceeds $18.00 per share for any 20 trading days within a 30-trading-day period ending on the third business day before the Company gives proper notice of such redemption to the warrant holders. The Private Placement Warrants are identical to the Public Warrants except that, so long as they are held by the former sponsor or its permitted transferees: (i) they will not be redeemable by the Company; (ii) they may be exercised by the holders on a cashless basis; and (iii) they are subject to registration rights. Any transactions related to the Warrants are recorded within the stockholders’ equity section of the Company’s consolidated financial statements. However, the issuance of shares pursuant to the exercise of these warrants is contingent upon the share price reaching $11.50. Therefore, share activity related to such warrants was not recorded as the contingency was not met during the reporting period. Earn-Out Agreement In connection with the Business Combination, stockholders of Shay immediately prior to the transaction (which stockholders consisted of certain affiliates of Platinum Equity, LLC and members of PAE management (the “Shay Stockholders”)) are entitled to receive up to an aggregate of 4,000,000 additional shares of Class A Common Stock (the “Earn-Out Shares”) if at any time during the five-year period following the Closing Date (the “Earn-Out Period”) the volume weighted average closing sale price of one share of Class A Common Stock on the Nasdaq (or the exchange which shares of Class A Common Stock are then listed) for a period of at least 10 days out of 20 consecutive trading days (the “Common Share Price”) exceeds certain thresholds, as described below. The thresholds (each a “Triggering Event”) causing the Earn-Out Shares to be issued by the Company to the Shay Stockholders is any such event that occurs within the Earn-Out period as follow: (i) a one-time issuance of 1,000,000 shares if the Common Share Price is greater than $13.00; (ii) a one-time issuance of 1,000,000 shares if the Common Share Price is greater than $15.50; (iii) a one-time issuance of 1,000,000 shares if the Common Share Price is greater than $18.00; and (iv) a one-time issuance of 1,000,000 shares if the Common Share Price is greater than $20.50. Further, if during the Earn-Out Period there is a change in control (as defined in the Merger Agreement) that results in the holders of Class A Common Stock receiving a per share price in respect of their Class A Common Stock that is equal to or greater than the applicable Common Share Price required in connection with any Triggering Event (an “Acceleration Event”), then any such Triggering Event that has not previously occurred will be deemed to have occurred, and the Company must issue Earn-Out Shares accordingly. If no Triggering Event is achieved within the Earn-Out Period, the Company will not be required to issue the Earn-Out Shares. No Triggering Event was achieved during the year ended December 31, 2020.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2016 Participation Plan On May 23, 2016, the Company adopted the Pacific Architects and Engineers Incorporated 2016 Participation Plan (the “2016 Participation Plan”). The purpose of the 2016 Participation Plan was to provide incentive compensation to key employees by granting performance units (“Units”). The Units were valued on the date of grant by the compensation committee of the pre-Business Combination company. Participants in the 2016 Participation Plan were entitled to receive compensation for their Units in the event that a qualifying event occurred. In connection with the Business Combination, which was a qualifying event, the 2016 Participation Plan was terminated immediately prior to the Closing Date and, in exchange for a release of claims relating to the plan, plan participants received payments totaling approximately $17.4 million. The $17.4 million was paid out during the first quarter of 2020, and was recorded as compensation expense. 2020 Incentive Plan Prior to the closing of the Business Combination, the Gores III Board of Directors and stockholders approved the PAE Incorporated 2020 Equity Incentive Plan (the “2020 Incentive Plan”). The 2020 Incentive Plan provides for the grant of stock options, stock appreciation rights, restricted stock units (RSUs) and other stock or cash-based awards. Restricted Stock Units During the year ended December 31, 2020, the Company issued 2,639,920 RSUs to certain employees out of the shares approved for issuance under the 2020 Incentive Plan. RSUs cliff vest in accordance with their respective service period or grade vest on an anniversary date, subject to the terms of the grant agreements and the 2020 Incentive Plan. Of the RSUs issued by the Company in 2020, 1,581,960 RSUs were issued to certain Company personnel pursuant to the terms of the Merger Agreement. The Company recognized $11.9 million in share-based compensation costs related to RSUs during the year ended December 31, 2020. As of December 31, 2020 the total compensation costs related to non-vested awards not yet recognized amounted to $7.4 million. These costs will be recognized over a weighted-average period of 1.6 years. Forfeitures are recognized in compensation costs as they occur. Activity related to RSUs during the year ended December 31, 2020 was as follows: As of December 31, 2020 Restricted Stock Unit Shares Weighted-Average Balance at December 31, 2019 — $ — Granted 2,639,920 7.45 Vested (34,366) 8.33 Forfeited (44,721) 7.56 Balance at December 31, 2020 2,560,833 $ 7.92 During the year ended December 31, 2020, the Company issued 631,219 performance-based restricted stock units (“PSUs”) to certain employees out of the shares approved for issuance under the 2020 Incentive Plan. These PSUs earn out over a three-year performance period, subject to the terms of the grant agreements and the 2020 Incentive Plan. The vesting of PSUs is contingent on the achievement of performance goals stated in the agreement, those being revenue growth, weighted at 50%, and EBITDA margin, weighted at 50%. Compensation costs are recognized when the performance conditions are satisfied or likely to be satisfied. The Company recognized $1.1 million in compensation costs related to PSUs during the year ended December 31, 2020. As of December 31, 2020 the total compensation costs related to non-vested awards not yet recognized amounted to $4.1 million. These costs will be recognized over weighted-average period of 2.0 years. Forfeitures are recognized in compensation costs as they occur. Activity related to PSUs during the year ended December 31, 2020 was as follows: As of December 31, 2020 Performance-based Restricted Stock Unit Shares Weighted-Average Balance at December 31, 2019 — $ — Granted 631,219 8.63 Vested — — Forfeited (22,082) 9.26 Balance at December 31, 2020 609,137 $ 9.28

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share Basic net income (loss) per common share is determined by dividing the net income (loss) attributed to stockholders by the weighted average number of common shares outstanding during the period presented. Diluted income (loss) per share is determined by adjusting the weighted average number of shares of common stock and common stock equivalents outstanding for the dilutive effect of common stock equivalents for the periods presented. The following table sets forth the computation of basic and diluted loss per share attributable to the Company’s common stockholders for the periods presented ( in thousands, except shares and per share amounts ): Year Ended December 31, December 31, December 31, 2020 2019 2018 Numerator: Net income (loss) attributed to PAE Incorporated $ 15,290 $ (49,809) $ (34,459) Denominator: Basic weighted average shares 84,114,016 21,127,823 21,127,823 Diluted weighted average shares 85,369,328 21,127,823 21,127,823 Basic income (loss) per share $ 0.18 $ (2.36) $ (1.63) Diluted income (loss) per share $ 0.18 $ (2.36) $ (1.63) The Company has not included the effect of 19,999,985 shares of Common Stock issuable upon the exercise of Warrants in the calculation of diluted net income (loss) per share for the year ended December 31, 2020. Warrants are excluded when the exercise price exceeds the average market value of the Company’s common stock price during the applicable period. The Company has not included the effect of 4,000,000 Earn-Out Shares in the calculation of basic and diluted net (loss) income per share for the year ended December 31, 2020. The condition for the issuance of these shares is based on the weighted average closing sale price of the Company’s Class A Common Stock and such condition has not been met as of December 31, 2020.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases At December 31, 2020, the Company had right-of-use (“ROU”) assets, net of $191.4 million and lease liabilities of $192.3 million recorded on the consolidated balance sheet. The Company rents certain facilities and equipment under operating leases. The Company’s total lease cost is recorded primarily within selling, general and administrative expenses on the consolidated statements of operations. Rents which are directly chargeable to a project are charged to cost of revenues. During the year ended December 31, 2020 and December 31, 2019, the Company recognized operating lease costs of approximately $55.7 million and $50.0 million, respectively. The Company’s future minimum operating lease payments for noncancelable operating leases were as follows ( in thousands ): December 31, 2020 2021 $ 48,547 2022 42,234 2023 37,212 2024 29,009 2025 22,558 Thereafter 54,509 Total future minimum lease payments 234,069 Less imputed interest 41,720 Present value of minimum lease payments 192,349 Less current maturities of lease liabilities 46,756 Long-term lease liabilities $ 145,593 The weighted-average remaining lease term and the weighted-average discount rate for the Company’s operating leases were approximately 7.0 years and 6.2%, respectively, at December 31, 2020. The Company made cash payments of approximately $44.0 million for operating leases for the year ended December 31, 2020, which are included in cash flows from operating activities in the consolidated statement of cash flows.

Legal Proceedings, Commitments,

Legal Proceedings, Commitments, and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings, Commitments, and Contingencies	Legal Proceedings, Commitments, and ContingenciesThe Company is a party to, or has property subject to, litigation and other proceedings. Management believes the probability is remote that the outcome of the matters will have a material adverse effect on its operations as a whole, notwithstanding that the unfavorable resolution of any matter may have a material effect on net earnings in a future period. The Company cannot predict the outcome of legal proceedings and loss or range of loss contingencies with certainty.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company's operations and reportable segments are organized around the nature of the services and products provided to customers. The Company defines its reportable segments based on the way the CODM manages the operations of the Company for purposes of allocating resources and assessing performance. The GMS operating segment provides support to the U.S. Government and its partners within and outside the United States providing sustainment, training and readiness support and advancing foreign policy objectives. The NSS operating segment provides a wide-ranging portfolio of offerings that support all facets of national security, including intelligence, homeland security and civil government missions. While the CODM uses a variety of different measures to evaluate the Company’s segments, the primary measures used to evaluate segment performance and allocate resources are revenues and operating income. As a result, interest expense, net and provision for income taxes as recorded on the consolidated statements of operations are not allocated to the Company’s operating segments. The following table shows information by reportable segment for the periods presented (in thousands): Year Ended December 31, December 31, December 31, 2020 2019 2018 Revenues GMS $ 2,080,474 $ 2,099,737 $ 1,968,843 NSS 634,154 664,156 639,719 Corporate — — — Total revenues $ 2,714,628 $ 2,763,893 $ 2,608,562 Operating income (loss) GMS $ 80,090 $ 92,386 $ 89,141 NSS 22,073 (36,940) (12,556) Corporate (11,397) (28,627) (26,464) Total operating income $ 90,766 $ 26,819 $ 50,121 Amortization of intangible assets GMS $ 16,461 $ 16,679 $ 18,492 NSS 17,693 16,526 17,288 Corporate — — — Total amortization of intangible assets $ 34,154 $ 33,205 $ 35,780 Under U.S. Government cost accounting standards, indirect costs including depreciation expense are collected in numerous indirect cost pools, which are then collectively allocated to the Company’s reportable segments based on a representative causal or beneficial relationship of the costs in the pool to the costs in the base. While depreciation expense is a component of the allocated costs, the allocation process precludes depreciation expense from being specifically identified by the Company’s individual reportable segments. For this reason, depreciation expense by reportable segment is not presented separately above. Asset information by segment is not a key measure of performance used by the CODM and therefore segment assets are not presented. Less than 10.0% of the Company’s revenues and tangible long-lived assets are generated by or owned by entities outside of the United States. Therefore, additional segment financial information by geographic location is not presented.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions Tax Overpayment/Underpayment Amount In connection with the Business Combination, the Shay Stockholders are entitled to a payment of the net cash savings in U.S. federal, state and local income tax that the post-closing company actually realizes (or is deemed to realize in certain circumstances) in periods after the Closing Date. The liability for this estimated payment and the corresponding charge to equity of $4.7 million are reflected in the Company’s consolidated balance sheets as of December 31, 2020. Advisory Services During the year ended December 31, 2020, December 31, 2019 and December 31, 2018, the Company recognized management fees, transaction and advisory fees, and related expenses of approximately $15.8 million, $5.1 million, and $5.0 million, respectively. As a result of the Business Combination $15.0 million was grouped with other similar transactional expenses and recorded as a reduction to the recapitalized equity and $0.8 million was recorded in selling, general and administrative expenses for the period ended December 31, 2020. The amount of $5.1 million and $5.0 million were recorded in selling, general and administrative expenses for the period ended December 31, 2019 and December 31, 2018, respectively These expenses were for services rendered by one or more affiliates of Platinum Equity, LLC.

Other Income, Net

Other Income, Net	12 Months Ended
	Dec. 31, 2020
Other Income and Expenses [Abstract]
Other Income, Net	Other Income, Net The components of other income, net consisted of the following for the periods presented (in thousands): Year Ended December 31, December 31, December 31, 2020 2019 2018 Net earnings (loss) of equity method investments $ 6,082 $ 2,454 $ (180) Gain on sale of fixed assets and other 1,190 7,331 5,160 Total $ 7,272 $ 9,785 $ 4,980

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On March 27, 2020, President Trump signed into U.S. federal law the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”), which is aimed at providing emergency assistance and health care for individuals, families, and businesses affected by the COVID-19 pandemic. The CARES Act, among other things, includes provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carry-back periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. In particular, under the CARES Act, for taxable years beginning in 2019 and 2020, the base for interest deductibility is increased from 30% to 50% of EBITDA. As of December 31, 2020, the Company estimated that the net tax benefit related to the CARES Act is approximately $2.4 million. The Company is expecting to defer $37.0 million of employer share Social Security tax under the CARES Act that will be paid equally by December 31, 2021 and 2022. The Company has analyzed the impact of the CARES Act on its financial statements. The domestic and foreign components of income before income taxes were as follows (in thousands) : Year Ended December 31, December 31, December 31, 2020 2019 2018 Domestic $ (80,255) $ (141,068) $ (94,924) Foreign 97,164 81,876 60,685 Income (loss) before income taxes $ 16,909 $ (59,192) $ (34,239) The components of the provision for income taxes were as follows (in thousands) : Year Ended December 31, December 31, December 31, 2020 2019 2018 Current Federal $ 1,414 $ — $ — State — — — Foreign 9,035 6,507 6,991 Total current expense (benefit) 10,449 6,507 6,991 Deferred Federal (7,366) (15,638) (9,652) State — — — Foreign — — — Total deferred (benefit) expense (7,366) (15,638) (9,652) Provision for income taxes $ 3,083 $ (9,131) $ (2,661) The differences between the amount of tax computed at the federal statutory rate and the provision for income taxes were as follows (in thousands) : Year Ended December 31, December 31, December 31, 2020 2019 2018 Amount computed at statutory federal income tax rate $ 3,785 $ (12,452) $ (7,471) Increases (decreases) in tax resulting from: CARES Act adjustment (2,435) — — Section 250 Deduction (2,834) (2,682) (743) Non taxable income (2,868) (1,071) (1,049) Non deductible compensation 1,735 — — Change in valuation allowance 4,180 5,601 7,026 Effect of foreign operations 87 135 505 Change in Uncertain tax position 2,272 237 553 Minority Interest 748 552 (29) Transaction costs (865) — — Other permanent differences, net (722) 549 (1,453) Provision for income taxes $ 3,083 $ (9,131) $ (2,661) During the years ended December 31, 2020, 2019 and 2018 the Company recognized a state income tax (benefit) expense of approximately $1.1 million, $(0.1) million and $(1.3) million, respectively, which are recorded in selling, general and administrative expenses in the consolidated statements of operations. The Tax Cuts and Jobs Act subjects a U.S. shareholder to a minimum tax on “global intangible low-taxed income” ("GILTI") earned by certain foreign subsidiaries. The FASB Staff Q&A, Topic 740 No. 5, Accounting for Global Intangible Low-Taxed Income, states that an entity can make an accounting policy election to either recognize deferred taxes for temporary differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI resulting from those items in the year the tax is incurred. The Company has elected to recognize the resulting tax on GILTI as a period expense in the period the tax is incurred and has incurred tax for the year ended December 31, 2020. As of December 31, 2020, 2019, and 2018, the Company had foreign tax credit carryforwards for federal tax purposes of approximately $36.0 million, $35.6 million and $33.1 million, respectively, which will expire from 2024 to 2030. As of December 31,2020, the Company had net operating loss (“NOL”) carryforwards and work opportunity tax credit (“WOTC”) for federal tax purposes of approximately $8.8 million and $1.0 million, respectively. The Federal NOL has an indefinite carryforward life and the WOTC will expire from 2037 and 2039. As of December 31, 2020, 2019, and 2018, the Company had net operating loss (“NOL”) carryforwards for state tax purposes of approximately $77.1 million, $77.7 million and $73.4 million, respectively, which will expire from 2020 to 2024. We record a net valuation allowance against deferred tax assets to the extent we believe these assets will more likely than not be realized. In making such determination, if the Company’s deferred tax are realizable, we consider all positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent results of operations. If we were to determine that we would be able to realize our deferred income tax assets in the future in excess of our net recorded amount or would no longer be able to realize our deferred income tax assets in the future as currently recorded, we would make an adjustment to the valuation allowance which would decrease or increase the provision for income taxes. Based on Company’s analysis on the realizability of the Company’s deferred tax as of December 31, 2020, the Company recorded an additional valuation allowance of $4.2 million before the prior year provision to return adjustment. The Company is subject to income taxes in the U.S. and various state and foreign jurisdictions. Tax statutes and regulations within each jurisdiction are subject to interpretation and require the application of significant judgment. The Company’s consolidated federal income tax returns through March 14, 2016 are no longer subject to audit. However, the Company is subject to U.S. Federal, state, and foreign tax examinations for years ranging from 1993 to 2018. The Company does not expect the resolution of these examinations to have a material impact on its results of operations, financial condition or cash flows. The Company has recorded other receivables from third parties related to the indemnification of certain international contingent tax liabilities, net of tax benefit, of approximately $5.0 million, $5.0 million and $13.6 million as of December 31, 2020, 2019 and 2018, respectively. The tax effects of temporary differences that give rise to deferred taxes are presented below ( in thousands ): 2020 2019 Deferred tax assets Accrued compensation benefits $ 14,416 $ 8,204 Reserves 5,171 4,670 Net operating loss and credit carryover 4,877 3,202 Foreign tax credit carryover 35,981 35,629 Tax reserve benefit 5,409 3,916 Interest carryover 2,080 16,438 Operating lease liability 43,280 39,283 Other 4,722 4,846 Total deferred tax assets 115,936 116,188 Valuation allowance (12,050) (13,784) Net deferred tax assets 103,886 102,404 Deferred tax liabilities Depreciation (4,087) (4,384) Prepaid expenses (3,341) (1,779) Unbilled receivables (2,178) (22,958) Intangible assets (54,908) (31,480) Operating lease right-of-use assets (43,034) (37,540) Investment in unconsolidated foreign subsidiary (727) (1,051) Total deferred tax liabilities (108,275) (99,192) Net deferred tax assets (liabilities) $ (4,389) $ 3,212 The changes in the unrecognized tax benefits, excluding accrued interest and penalties, were as follows ( in thousands): Year Ended December 31, December 31, December 31, 2020 2019 2018 Beginning of the year $ 1,958 $ 2,262 $ 3,614 Additions and (subtractions) on position taken during current year 3,799 (304) — Additions and (subtractions) on position taken in prior periods 1,478 — — Reductions due to settlements — — (1,352) End of the year $ 7,235 $ 1,958 $ 2,262

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) The following table shows selected quarterly data for the periods presented ( in thousands ): December 31, September 27, June 28, March 29, 2020 2020 2020 2020 Revenues $ 787,833 $ 666,240 $ 643,303 $ 617,253 Costs of revenues 623,390 512,877 496,678 465,208 Operating income 20,482 28,532 34,295 7,457 Net (loss) income $ (8,913) $ 10,731 $ 16,786 $ (4,777) December 31, September 29, June 30, March 31, 2019 2019 2019 2019 Revenues $ 697,085 $ 697,717 $ 695,607 $ 673,484 Costs of revenues 559,940 565,703 540,772 517,159 Operating (loss) income (3,167) (10,525) 26,158 14,353 Net (loss) income $ (16,664) $ (31,625) $ 3,388 $ (5,160)

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn January 31, 2021, PAE Aviation and Technical Services LLC, a Delaware limited liability company (“PAE AvTech”), an indirect wholly owned subsidiary of the Company, acquired the 49% minority interest of Parsons Government Services, Inc. in the DZSP 21 LLC joint venture for a purchase price of $15.8 million, subject to customary purchase price adjustments as set forth in the purchase agreement. Following the completion of this transaction, PAE AvTech owns 100% of DZSP 21 LLC and all the rights, duties and obligations under the DZSP 21 LLC operating agreement and the Guam contracts, all as set forth in the purchase agreement.

Significant Accounting Princi_2

Significant Accounting Principles and Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Segment Reporting	The Company’s operations are currently organized into the following two reportable segments: • Global Mission Services (“GMS”): GMS provides infrastructure and logistics management, international logistics and stabilization support, and aircraft and vehicle readiness and sustainment support. The segment focuses on customer relationships with DoD, DoS, NASA, and other government agencies for work both in the United States and outside of the United States. • National Security Solutions (“NSS”): NSS provides counter-threat solutions, business process outsourcing, adjudication support services and full life cycle support for complex Segment Reporting The Company’s operations and reportable segments are organized around the nature of the products and services provided to customers. The Company defines its reportable segments based on the way the chief operating decision maker (“CODM”), currently its President and Chief Executive Officer, manages the operations of the Company for purposes of allocating resources and assessing performance. Although information regarding certain capabilities and markets served may be discussed for purposes of promoting an understanding of the business, the Company manages its business and allocates resources based on the two segments.
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”) for annual financial information. In management’s opinion, all adjustments, consisting of only normal recurring adjustments, considered necessary for a fair presentation have been included. The Company closes its books and records on the last Sunday of the calendar quarter to align its financial closing with its business process. This practice only affects interim periods, as the Company’s fiscal year ends on December 31, and therefore the closing of books and records for the year ends reflected in this Annual Report on Form 10-K were December 31, 2020 and December 31, 2019 and December 31, 2018, respectively. The consolidated financial statements and disclosures included herein are labeled based on that convention. The consolidated financial statements include the accounts of PAE Incorporated and subsidiaries and ventures in which the Company owns more than 50% or otherwise controls. All intercompany amounts have been eliminated in consolidation.
Use of Estimates	Use of Estimates These consolidated financial statements are prepared in conformity with U.S. GAAP, which requires the use of estimates and assumptions, including assumptions to determine the fair value of acquired assets and liabilities, recoverability of long-lived assets, goodwill, valuation allowances on deferred taxes, inputs used in stock based compensation and anticipated contract costs and revenues utilized in the earnings recognition process, which affect the reported amounts in the consolidated financial statements and accompanying notes. Due to the size and nature of many of the Company’s programs, the estimation of total revenues and cost at completion is subject to a wide range of variables, including assumptions for timing and risks. Actual results may differ from management’s estimates and changes in these estimates are recorded when known.
Revenue Recognition and Contract Assets and Contract Liabilities	Revenue Recognition As of January 1, 2018, the Company adopted Accounting Standards Codification (“ASC”) 606, Revenues From Contracts With Customers (Topic 606) using the modified retrospective method. The majority of the Company’s revenues are generated from contracts with the U.S. Government and its agencies. The Company enters into a variety of contract types, including fixed price, cost reimbursable, and time and materials contracts. The Company accounts for a contract when it has been approved by all parties in the arrangement, the rights of the parties and payment terms are identified, and collectability of the consideration is reasonably assured. At contract inception, the Company identifies distinct goods or services promised in the contract, referred to as performance obligations, and then determines the transaction price for the contract. The transaction price can be a fixed or variable amount, and contracts can contain award fees, incentive fees or other provisions that can either increase or decrease the transaction price. These variable amounts generally are awarded upon achievement of certain performance metrics, program milestones or cost targets and can be based upon customer discretion. The Company estimates variable consideration at the most likely amount to which it expects to be entitled. Estimated amounts of variable consideration are included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with all variable consideration is resolved or recognized. The Company’s estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of anticipated performance and historical, current and forecasted information that is reasonably available. The Company’s contracts contain promises to provide distinct goods or services to its customers. These represent separate performance obligations and units of account. Management evaluates whether a single contract should be accounted for as more than one performance obligation or whether two or more contracts should be combined and accounted for as one single arrangement at the outset of the contract. Most of the Company’s contracts consist of providing a complex set of interrelated goods and services that together provide a single deliverable or solution to the customer, and accordingly are accounted for as a single performance obligation. The Company also may engage with a customer on a contract that contains multiple distinct goods or services. In such circumstance, multiple performance obligations exist, and the Company allocates the contract’s transaction price to the individual performance obligations based on estimated relative standalone selling price. The primary method used to estimate standalone selling price is the expected cost plus a margin approach, under which the Company forecasts expected costs of satisfying a performance obligation and then adds an appropriate margin for that distinct good or service promised. Revenue is recognized when, or as, the performance obligation is satisfied. For substantially all of the Company’s contracts, the Company satisfies its performance obligations over time as the Company’s customer simultaneously receives and consumes benefits. In such instances, revenue is recognized over time when transfer of control to the customer occurs. For U.S. Government contracts, this ongoing obligation to deliver goods or services is supported by clauses in the contract that allow the U.S. Government to unilaterally terminate the contract for convenience, pay for costs incurred plus a reasonable profit and take control of any work in process. When a transfer of control occurs over time, revenue is recognized based on the extent of progress towards completion of the performance obligation. Based on the nature of the products and services provided in the contract, the Company uses judgment to determine if an input measure or output measure best depicts the transfer of control over time. For services contracts, performance obligations are typically satisfied as services are rendered and the Company uses a contract cost-based input method to measure progress. Contract costs include labor, material and allocable indirect expenses. Revenue is recognized proportionally as contract costs are incurred plus estimated fees. If a contract does not meet the criteria for recognizing revenue over time, revenue is recognized at the point in time when control of the good or service is transferred to the customer. Control is considered to have transferred when the customer has legal title and the Company has a right to payment. Contracts are often modified to account for changes in contract specifications and requirements. Contract modifications impact a performance obligation when the modification either creates new, or changes the existing, enforceable rights and obligations. The effect of a contract modification on the transaction price and the measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue under the cumulative catch-up method. Significant changes in one or more estimates could affect the profitability of a contract. Adjustments are recognized in estimated profit on contracts in the period identified. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, the Company recognizes that loss in the period it is identified. Management reviews the progress and execution of performance obligations under the estimate at completion process. As part of this process, management reviews information including, but not limited to, key contract terms and conditions, program schedule, progress towards completion, identified risks and opportunities and the related changes in estimates of revenues and costs. The risks and opportunities include management’s judgment about the ability and cost to achieve the contract milestones and other technical contract requirements. Management must make assumptions and estimates regarding labor productivity and availability, the complexity of the work to be performed, the availability of materials, the length of time to complete the performance obligation, execution by subcontractors, the availability and timing of funding from customers and overhead cost rates, among other variables. A significant change in one or more of these estimates could affect the profitability of the Company’s contracts. Contract Assets Contract assets primarily consist of unbilled receivables which represent rights to payment for work or services completed but not billed as of the reporting date. Contract assets are classified as unbilled receivables within accounts receivable, net on the consolidated balance sheets. Contract Liabilities Contract liabilities are advances and milestone payments from customers on certain contracts that exceed revenue earned to date. Contract liabilities are reported as customer advances and billings in excess of costs on the consolidated balance sheets.
Operating Expenses	Operating Expenses Operating expenses include all cost of revenues, selling, general and administrative expenses, amortization of intangible assets, and depreciation of fixed assets. Cost of revenues includes costs related to labor, material, subcontract labor and other costs that are allowable and allocable to contracts under federal procurement standards. Selling, general and administrative expenses primarily consist of (i) fringe benefits related to the contract costs; (ii) salaries and wages plus associated fringe benefits and occupancy costs related to executive and senior management, business development, bid and proposal, contracts administration, finance and accounting, human resources, recruiting, information systems support, legal and corporate governance; and (iii) unallowable costs under applicable procurement standards that are not allocable to contracts for billing purposes. Unallowable costs do not generate revenue, but are necessary for business operations.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers cash on deposit and all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. The Company does not maintain any restricted cash.
Accounts Receivable, net	Accounts Receivable, net Amounts billed and due from customers are recorded as billed receivables within accounts receivable, net on the consolidated balance sheets. Generally, customer accounts are due within 30 to 45 days of billings. The Company recognizes an allowance for credit losses based on historical experience, current conditions and reasonable and supportable forecasts. The Company assesses its overall allowance for credit losses at least on a quarterly basis. Prior to the implementation of Accounting Standards Update (“ASU”) 2016-13 “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”), the Company recorded adjustments to an allowance for doubtful accounts when collectability was uncertain. For further information on the effect of adoption of ASU 2016-13, refer to Note 3 – “Recent Accounting Pronouncements – Accounting Pronouncements Adopted”.
Concentration of Credit Risk	Concentration of Credit Risk The Company’s receivables are highly concentrated with agencies of the U.S. Government. Approximately 91.4% and 96.0% of receivables as of December 31, 2020 and 2019, respectively, were generated from contracts with the U.S. Government. Approximately 90.0% and 93.0% of revenues for the years ended December 31, 2020 and 2019, respectively, were related to contracts with the U.S. Government. The Company believes that credit risk related to its accounts receivable is limited due to a large number of customers in differing segments and agencies of the U.S. Government, as well as the creditworthiness of the U.S. Government.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. The Company calculates depreciation and amortization using a straight-line method over the estimated useful lives of assets. The estimated useful life of machinery and equipment is 4 to 20 years, computer software and equipment is 3 to 7 years, transportation equipment is 4 to 11 years, furniture and fixtures is 5 to 12 years, and leasehold improvements is 3 to 16 years.
Goodwill	Goodwill Goodwill represents the excess of the fair value of consideration transferred, plus the fair value of any non-controlling interests in the acquiree, over the fair value of the net assets acquired and liabilities assumed as of the acquisition date. Goodwill is not amortized, but instead is tested annually for impairment at the reporting unit level and tested more frequently if events or circumstances indicate that the carrying value may not be recoverable. The Company’s policy is to perform its annual goodwill impairment evaluation as of the first day of the fourth quarter of its fiscal year. The Company may first assess qualitative factors to evaluate whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount or elect to bypass such assessment. If it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying value, or the Company elects to bypass such assessment, the Company then determines the fair value of each reporting unit quantitatively. The fair value of each reporting unit is compared to the carrying amount of the reporting unit. If the carrying amount of the reporting unit exceeds the fair value, then an impairment loss is recognized for the difference. The results of the Company’s annual goodwill impairment test for 2020, 2019 and 2018 indicated that no impairment existed. See Note 9 - “Goodwill and Intangible Assets” for additional information. The evaluation includes comparing the fair value of each of the reporting units using a discounted cash flow methodology, or other fair value measures as considered appropriate in the circumstances, to its net book value, including goodwill. If the net book value exceeds the fair value, the Company will measure impairment by comparing the derived fair value of goodwill to its carrying value, and any impairment is recorded in the current period.
Intangible Assets	Intangible Assets Intangible assets consist of customer relationships, technology and trade name and are recognized at their estimated fair values at the date of acquisition. The Company amortizes intangible assets using an accelerated method that best approximates the proportion of the future cash flows estimated to be generated in each period over the estimated useful lives of the applicable assets. On an annual basis, the Company evaluates this method to ensure continued appropriateness unless the estimated useful lives are determined to be indefinite or the estimated cash flows indicate another pattern of amortization should be used. The Company amortizes acquired intangibles over the following periods: Customer relationships 6-13 years Technology 3-5 years Trade name 5-10 years
Impairment of Certain Long-Lived Assets	Impairment of Certain Long-Lived AssetsThe Company reviews the carrying values of long-lived assets other than goodwill for impairment if events or changes in the facts and circumstances indicate that their carrying values may not be recoverable. The Company assesses impairment by comparing the estimated undiscounted future cash flows of the related assets to the carrying value. If an asset is determined to be impaired, the Company would recognize an impairment charge in the current period for the difference between the fair value of the asset and the carrying amount.
Leases	Leases The Company adopted ASC 842, Leases (Topic 842) effective January 1, 2019, which changed the way the Company accounts for its leases. The Company’s leases are generally for facilities and office space and are classified as operating leases. A contract is determined to be a leasing arrangement at inception. A right-of-use (“ROU”) asset represents the right to control the use of an identified asset over the lease term and a lease liability represents the obligation to make lease payments arising from the lease. If a lease arrangement is determined to exist, a ROU asset and corresponding lease liability are recorded on the balance sheet at the lease commencement date based on the present value of lease payments over the lease term. The Company uses the incremental borrowing rate on the lease commencement date to determine the present value of lease payments. Operating lease expenses for the Company’s operating leases are recognized on a straight-line basis over the lease term. Certain operating leases may contain renewal or termination options that are reasonably certain of exercise. Lease and non-lease components are accounted for together as a single lease component for operating leases.
Consolidation Investments and Equity Method Investments	Consolidated Investments and Equity Method Investments The Company consolidates an investment when it has determined that the investment is a variable interest entity (“VIE”) and that the Company is the primary beneficiary. This determination is made at the inception of the Company’s involvement with the investment, in accordance with U.S. GAAP, and is reevaluated when facts and circumstances change. The Company considers both qualitative and quantitative factors to form a conclusion as to whether it, or another interest holder, has the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance. The Company also considers qualitative and quantitative factors to determine if it, or another interest holder, has the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could be significant to the VIE. The Company also consolidates ventures that are not VIEs when it has a controlling interest. When the Company consolidates an entity that is not wholly owned, the Company records the minority interests in the entity as a component of non-controlling interests in the stockholders’ equity section of the consolidated balance sheets. The Company has included the non-controlling interest in earnings of ventures within the consolidated net income and deducted the same amount to derive net income attributable to the Company. Other investments are accounted for under the equity method of accounting. These investments consist of ventures determined to be VIEs when the Company is not deemed to be the primary beneficiary and ventures that are not VIEs that the Company accounts for under the voting interest model when the Company has significant influence but not control. Significant influence generally is presumed to exist when the Company’s ownership in the investee is 20% or greater, unless other factors indicate otherwise. Under the equity method of accounting, the Company’s share of the net earnings or losses of the investee is included in other income, net on the accompanying consolidated statements of operations.
Stock-Based Compensation	Stock-Based CompensationCompensation expense for stock-based awards to employees that vest over a specific service period, is recognized in the consolidated statements of operations based on their grant date fair value and straight-line over the vesting period of the awards. For stock-based awards that vest based on the achievement of related performance conditions, compensation expense is recognized based on the expected achievement of the related performance conditions at the end of each reporting period over the vesting period of the award. If the Company’s initial estimates of the achievement of the performance conditions change, the related stock-based compensation expense and timing may fluctuate from period to period based on those estimates. If the performance conditions are not met, no stock-based compensation expense will be recognized, and any previously recognized stock-based compensation expense will be reversed. Forfeitures are recognized in compensation costs when those occur.
Foreign Currency Translation	Foreign Currency Translation The assets and liabilities of the Company’s foreign subsidiaries whose functional currency is other than the U.S. dollar are translated at the exchange rate in effect on the reporting date, while income and expenses are translated at the weighted-average exchange rate during the period. The Company’s primary practice is to negotiate contracts in the same currency in which the predominant expenses are incurred, thereby mitigating the exposure to foreign currency fluctuations. The net translation gains and losses are not included in determining net income, but are accumulated as a separate component of equity. Foreign currency transaction gains and losses are included in other income, net in the accompanying consolidated statements of operations.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method in accordance with the accounting standard for income taxes. The asset and liability method requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities. Under this method, changes in tax rates and laws are recognized in income in the period such changes are enacted. The Company records net deferred tax assets to the extent that it believes these assets will more likely than not be realized. In making such determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent results of operations. If the Company determines that it will be able to realize its deferred income tax assets in the future in excess of their net recorded amount or will no longer be able to realize its deferred income tax assets in the future as currently recorded, the Company makes an adjustment to the valuation allowance that will decrease or increase, respectively the provision for income taxes. The provision for federal, state, foreign and local income taxes is calculated on income before income taxes based on current tax law and includes the cumulative effect of any changes in tax rates from those used previously in determining deferred tax assets and liabilities. Such provision differs from the amounts currently payable because certain items of income and expense are recognized in different reporting periods for financial reporting purposes than for income tax purposes. The Company recognizes liabilities for uncertain tax positions when it is more likely than not that a tax position will not be sustained upon examination and settlement with various taxing authorities. Liabilities for uncertain tax positions are determined based upon the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. The Company recognizes interest and penalties related to uncertain tax positions in its income tax expense (benefit) on the consolidated statements of operations. For further discussion on uncertain tax positions which were settled for amounts different than recorded amounts see Note 21 - “Income Taxes”.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other comprehensive income (loss) refers to revenue, expenses, and gains and losses that, under U.S. GAAP, are included in comprehensive income (loss), but excluded from the determination of net income (loss).
Net Income (Loss) Per Share	Net Income (Loss) Per ShareBasic net income (loss) per common share is determined by dividing the net income (loss) allocable to stockholders by the weighted average number of common shares outstanding during the periods presented. Diluted income (loss) per share is computed by dividing the net income (loss) allocable to common stockholders by the weighted average number of shares of common stock and common stock equivalents outstanding for the dilutive effect of common stock equivalents for the period.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between marketplace participants at the measurement date. The valuation techniques the Company utilizes to measure the fair value of financial instruments are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect internal market assumptions. These two types of inputs create the following fair value hierarchy: • Level 1 – Quoted prices for identical instruments in observable active markets. • Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 – Significant inputs to the valuation model are unobservable and reflect Company’s own estimates and assumptions. The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, and amounts included in other current assets and current liabilities that meet the definition of a financial instrument approximate fair value because of the short-term nature of these amounts.
Accounting Pronouncements Adopted	Accounting Pronouncements Adopted In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842 “ASU 2016-02”), which supersedes the current lease guidance under ASC 840 Leases (Topic 840). Management adopted ASU 2016-02 on January 1, 2019, electing to use the package of practical expedients permitted under the transition guidance that allows for the carry forward of historical lease classification for existing leases on the adoption date and does not require the assessment of existing lease contracts to determine whether the contracts contain a lease or initial direct costs. Prior periods were not retrospectively adjusted. The adoption of this standard resulted in the recognition of ROU assets and lease liabilities for operating leases on the consolidated balance sheet. There was no cumulative impact to retained earnings and the January 1, 2019 adoption of ASC 842 did not have a material impact to either the consolidated statements of operations or cash flows. In June 2016, the FASB issued Accounting Standards Update ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses for Financial Instruments, which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost, replacing the existing incurred loss impairment model. The new standard is effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted this guidance effective January 1, 2020 under the modified retrospective method and such adoption did not have a material impact on the Company’s financial statements. In August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Topic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract, which requires the tracking and recognition of costs that will be capitalized as an asset and amortized over the assets useful life. The new standard is effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted this guidance effective January 1, 2020 prospectively and the standard did not have a material impact on the Company’s financial statements. Accounting Pronouncements Not Yet Adopted

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregated Revenues	Disaggregated revenues by customer type were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total DoD $ 807,722 $ 277,134 $ 1,084,856 Other U.S. government agencies 1,079,345 264,185 1,343,530 Commercial and non-U.S. customers 193,407 92,835 286,242 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total DoD $ 858,623 $ 222,978 $ 1,081,601 Other U.S. government agencies 1,123,459 359,681 1,483,140 Commercial and non-U.S. customers 117,655 81,497 199,152 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total DoD $ 784,532 $ 205,404 $ 989,936 Other U.S. government agencies 1,096,193 359,977 1,456,170 Commercial and non-U.S. customers 88,118 74,338 162,456 Total $ 1,968,843 $ 639,719 $ 2,608,562 Revenues by contract type were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total Cost-reimbursable $ 1,182,865 $ 166,026 $ 1,348,891 Fixed-price 676,714 269,530 946,244 Time and materials 220,895 198,598 419,493 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total Cost-reimbursable $ 1,206,710 $ 105,360 $ 1,312,070 Fixed-price 717,595 286,366 1,003,961 Time and materials 175,432 272,430 447,862 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total Cost-reimbursable $ 1,229,707 $ 90,061 $ 1,319,768 Fixed-price 595,127 281,859 876,986 Time and materials 144,009 267,799 411,808 Total $ 1,968,843 $ 639,719 $ 2,608,562 Disaggregated revenues by geographic location were as follows ( in thousands ): Year Ended December 31, 2020 GMS NSS Total United States $ 1,104,536 $ 626,961 $ 1,731,497 International 975,938 7,193 983,131 Total $ 2,080,474 $ 634,154 $ 2,714,628 Year Ended December 31, 2019 GMS NSS Total United States $ 1,090,765 $ 657,706 $ 1,748,471 International 1,008,972 6,450 1,015,422 Total $ 2,099,737 $ 664,156 $ 2,763,893 Year Ended December 31, 2018 GMS NSS Total United States $ 1,013,830 $ 635,158 $ 1,648,988 International 955,013 4,561 959,574 Total $ 1,968,843 $ 639,719 $ 2,608,562

Contract Assets and Contract _2

Contract Assets and Contract Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Components of Contract Assets and Contract Liabilities	Contract assets and contract liabilities consisted of the following as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 Contract assets $ 360,552 $ 295,103 Contract liabilities $ 106,475 $ 51,439

Business Combinations and Acq_2

Business Combinations and Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The major classes of assets and liabilities to which the purchase price was allocated were as follows: (in thousands) Fair Value Cash and cash equivalents $ 3,202 Accounts receivable 72,636 Prepaid expenses and other current assets 3,454 Property and equipment 2,848 Operating lease right-of-use assets 21,137 Intangible assets 74,100 Total assets acquired 177,377 Accounts payable 30,212 Accrued expenses 1,159 Customer advances and billings in excess of costs 2,965 Salaries, benefits and payroll taxes 7,969 Deferred income taxes 12,402 Operating lease liabilities, current portion 2,996 Other current liabilities 1,423 Long-term operating lease liabilities 18,038 Total liabilities assumed 77,164 Net identifiable assets acquired 100,213 Goodwill 125,113 Total estimated consideration transferred $ 225,326 (in thousands) Fair Value Cash and cash equivalents $ 5,469 Accounts receivable 15,905 Prepaid expenses and other current assets 621 Property and equipment 27 Operating lease right-of-use assets 599 Intangible assets 37,800 Other noncurrent assets 63 Total assets acquired 60,484 Accounts payable 2,454 Accrued expenses 1,056 Customer advances and billings in excess of costs 3,420 Salaries, benefits and payroll taxes 5,486 Deferred income taxes 7,700 Operating lease liabilities, current portion 355 Long-term operating lease liabilities 240 Total liabilities assumed 20,711 Net identifiable assets acquired 39,773 Goodwill 55,967 Total estimated consideration transferred $ 95,740
Schedule of Intangible Assets Acquired	Intangible assets acquired were as follows: (in thousands, except years) Weighted-average Amortization Period Fair Value Customer Relationships 10 $ 71,800 Trade Name & Trademarks 7 2,300 Total intangible assets 10 $ 74,100 Intangible assets acquired were as follows: (in thousands, except years) Weighted-average Amortization Period Fair Value Customer Relationships 11 $ 32,200 Trade Name & Trademarks 7 5,600 Total intangible assets 10 $ 37,800

Accounts Receivable, net (Table

Accounts Receivable, net (Tables)	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Components of Accounts Receivable, Net	The components of Accounts receivable, net consisted of the following as of the dates presented (in thousands): December 31, December 31, 2020 2019 Billed receivables $ 227,787 $ 148,747 Unbilled receivables 360,552 295,103 Less allowance for credit losses (2,828) (1,670) Total accounts receivables, net $ 585,511 $ 442,180

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Components of Property and Equipment, net	The components of property and equipment, net consisted of the following as of the dates presented (in thousands): December 31, December 31, 2020 2019 Assets not yet in service $ 2,111 $ 301 Leasehold improvements 11,906 9,823 Machinery and equipment 12,839 12,094 Computer and equipment 36,119 34,894 Transportation equipment 13,519 14,043 Furniture and fixtures 2,353 2,797 Property and equipment, gross 78,847 73,952 Less accumulated depreciation and amortization (51,232) (43,548) Total property and equipment, net $ 27,615 $ 30,404

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table presents changes in the carrying amount of goodwill by reportable segment for the periods presented (in thousands): GMS NSS Total Balance as of December 31, 2018 $ 208,593 $ 199,432 $ 408,025 Acquisitions — — — Other — 1,563 1,563 Balance as of December 31, 2019 $ 208,593 $ 200,995 $ 409,588 Acquisitions — 181,080 181,080 Other — — — Balance as of December 31, 2020 $ 208,593 $ 382,075 $ 590,668
Intangible Assets, net	The components of intangible assets, net consisted of the following as of the dates presented (in thousands): December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 390,900 $ (149,163) $ 241,737 Technology 1,700 (1,700) — Trade name 24,800 (8,327) 16,473 Total $ 417,400 $ (159,190) $ 258,210 December 31, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 286,900 $ (116,923) $ 169,977 Technology 1,700 (1,700) — Trade name 16,900 (6,413) 10,487 Total $ 305,500 $ (125,036) $ 180,464
Estimated Amortization Expense in Future Years	Estimated amortization expense in future years is expected to be: As of December 31, 2020 2021 $ 50,106 2022 50,089 2023 40,666 2024 33,782 2025 28,015 Thereafter 55,552 Total $ 258,210

Consolidated Variable Interes_2

Consolidated Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The cash flows generated by these VIEs are included within the Company’s consolidated statements of cash flows. The consolidated balance sheets include the following amounts from these consolidated VIEs as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 Assets Total assets $ 145,664 $ 127,742 Liabilities and equity Total liabilities $ 96,318 $ 80,151 Total equity 49,346 47,591 Total liabilities and equity $ 145,664 $ 127,742 The consolidated statements of operations include the following amounts from consolidated VIEs for the periods presented ( in thousands ): Year Ended December 31, December 31, December 31, 2020 2019 2018 Income statements Revenues $ 369,966 $ 340,063 $ 259,386 Cost of revenues 301,345 311,310 205,730 Selling, general and administrative expenses 73,400 80,942 84,473 Total operating expenses 374,745 392,252 290,203 Program loss (4,779) (52,189) (30,817) Other income (loss), net 908 (1,697) (1,093) Net loss $ (3,871) $ (53,886) $ (31,910)

Other current liabilities (Tabl

Other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Other Current Liabilities	Other current liabilities consisted of the following as of the dates presented (in thousands): December 31, December 31, 2020 2019 Reserves $ 13,617 $ 11,659 Accrued foreign taxes 13,227 6,053 Accrued losses on contracts 11,455 11,352 Other 6,738 1,829 Total current liabilities $ 45,037 $ 30,893

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-term Debt	Long-term debt consisted of the following as of the dates presented ( in thousands ): December 31, December 31, 2020 2019 First Term Loan $ 890,000 $ 506,772 Second Term Loan — 265,329 2020 ABL Credit Agreement — — Total debt 890,000 772,101 Unamortized discount and debt issuance costs (23,733) (22,164) Total debt, net of discount and debt issuance costs 866,267 749,937 Less current maturities of long-term debt (5,961) (22,007) Total long-term debt, net of current $ 860,306 $ 727,930
Future Principal Maturities of Long-Term Debt	Future principal maturities of the Company’s long-term debt are summarized as follows ( in thousands ): As of December 31, 2020 2021 $ 8,900 2022 8,900 2023 8,900 2024 8,900 2025 8,900 Thereafter 845,500 Total $ 890,000

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of RSUs	Activity related to RSUs during the year ended December 31, 2020 was as follows: As of December 31, 2020 Restricted Stock Unit Shares Weighted-Average Balance at December 31, 2019 — $ — Granted 2,639,920 7.45 Vested (34,366) 8.33 Forfeited (44,721) 7.56 Balance at December 31, 2020 2,560,833 $ 7.92
Schedule of PSUs	Activity related to PSUs during the year ended December 31, 2020 was as follows: As of December 31, 2020 Performance-based Restricted Stock Unit Shares Weighted-Average Balance at December 31, 2019 — $ — Granted 631,219 8.63 Vested — — Forfeited (22,082) 9.26 Balance at December 31, 2020 609,137 $ 9.28

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Loss Per Share	The following table sets forth the computation of basic and diluted loss per share attributable to the Company’s common stockholders for the periods presented ( in thousands, except shares and per share amounts ): Year Ended December 31, December 31, December 31, 2020 2019 2018 Numerator: Net income (loss) attributed to PAE Incorporated $ 15,290 $ (49,809) $ (34,459) Denominator: Basic weighted average shares 84,114,016 21,127,823 21,127,823 Diluted weighted average shares 85,369,328 21,127,823 21,127,823 Basic income (loss) per share $ 0.18 $ (2.36) $ (1.63) Diluted income (loss) per share $ 0.18 $ (2.36) $ (1.63)

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Future Minimum Operating Lease Payments	The Company’s future minimum operating lease payments for noncancelable operating leases were as follows ( in thousands ): December 31, 2020 2021 $ 48,547 2022 42,234 2023 37,212 2024 29,009 2025 22,558 Thereafter 54,509 Total future minimum lease payments 234,069 Less imputed interest 41,720 Present value of minimum lease payments 192,349 Less current maturities of lease liabilities 46,756 Long-term lease liabilities $ 145,593

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Information by Reportable Segment	The following table shows information by reportable segment for the periods presented (in thousands): Year Ended December 31, December 31, December 31, 2020 2019 2018 Revenues GMS $ 2,080,474 $ 2,099,737 $ 1,968,843 NSS 634,154 664,156 639,719 Corporate — — — Total revenues $ 2,714,628 $ 2,763,893 $ 2,608,562 Operating income (loss) GMS $ 80,090 $ 92,386 $ 89,141 NSS 22,073 (36,940) (12,556) Corporate (11,397) (28,627) (26,464) Total operating income $ 90,766 $ 26,819 $ 50,121 Amortization of intangible assets GMS $ 16,461 $ 16,679 $ 18,492 NSS 17,693 16,526 17,288 Corporate — — — Total amortization of intangible assets $ 34,154 $ 33,205 $ 35,780

Other Income, Net (Tables)

Other Income, Net (Tables)	12 Months Ended
	Dec. 31, 2020
Other Income and Expenses [Abstract]
Components of Other Income, Net	The components of other income, net consisted of the following for the periods presented (in thousands): Year Ended December 31, December 31, December 31, 2020 2019 2018 Net earnings (loss) of equity method investments $ 6,082 $ 2,454 $ (180) Gain on sale of fixed assets and other 1,190 7,331 5,160 Total $ 7,272 $ 9,785 $ 4,980

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Domestic and Foreign Components of Income Before Income Taxes	The domestic and foreign components of income before income taxes were as follows (in thousands) : Year Ended December 31, December 31, December 31, 2020 2019 2018 Domestic $ (80,255) $ (141,068) $ (94,924) Foreign 97,164 81,876 60,685 Income (loss) before income taxes $ 16,909 $ (59,192) $ (34,239)
Components of Provision for Income Taxes	The components of the provision for income taxes were as follows (in thousands) : Year Ended December 31, December 31, December 31, 2020 2019 2018 Current Federal $ 1,414 $ — $ — State — — — Foreign 9,035 6,507 6,991 Total current expense (benefit) 10,449 6,507 6,991 Deferred Federal (7,366) (15,638) (9,652) State — — — Foreign — — — Total deferred (benefit) expense (7,366) (15,638) (9,652) Provision for income taxes $ 3,083 $ (9,131) $ (2,661)
Effective Income Tax Rate Reconciliation	The differences between the amount of tax computed at the federal statutory rate and the provision for income taxes were as follows (in thousands) : Year Ended December 31, December 31, December 31, 2020 2019 2018 Amount computed at statutory federal income tax rate $ 3,785 $ (12,452) $ (7,471) Increases (decreases) in tax resulting from: CARES Act adjustment (2,435) — — Section 250 Deduction (2,834) (2,682) (743) Non taxable income (2,868) (1,071) (1,049) Non deductible compensation 1,735 — — Change in valuation allowance 4,180 5,601 7,026 Effect of foreign operations 87 135 505 Change in Uncertain tax position 2,272 237 553 Minority Interest 748 552 (29) Transaction costs (865) — — Other permanent differences, net (722) 549 (1,453) Provision for income taxes $ 3,083 $ (9,131) $ (2,661)
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to deferred taxes are presented below ( in thousands ): 2020 2019 Deferred tax assets Accrued compensation benefits $ 14,416 $ 8,204 Reserves 5,171 4,670 Net operating loss and credit carryover 4,877 3,202 Foreign tax credit carryover 35,981 35,629 Tax reserve benefit 5,409 3,916 Interest carryover 2,080 16,438 Operating lease liability 43,280 39,283 Other 4,722 4,846 Total deferred tax assets 115,936 116,188 Valuation allowance (12,050) (13,784) Net deferred tax assets 103,886 102,404 Deferred tax liabilities Depreciation (4,087) (4,384) Prepaid expenses (3,341) (1,779) Unbilled receivables (2,178) (22,958) Intangible assets (54,908) (31,480) Operating lease right-of-use assets (43,034) (37,540) Investment in unconsolidated foreign subsidiary (727) (1,051) Total deferred tax liabilities (108,275) (99,192) Net deferred tax assets (liabilities) $ (4,389) $ 3,212
Changes in Unrecognized Tax Benefits	The changes in the unrecognized tax benefits, excluding accrued interest and penalties, were as follows ( in thousands): Year Ended December 31, December 31, December 31, 2020 2019 2018 Beginning of the year $ 1,958 $ 2,262 $ 3,614 Additions and (subtractions) on position taken during current year 3,799 (304) — Additions and (subtractions) on position taken in prior periods 1,478 — — Reductions due to settlements — — (1,352) End of the year $ 7,235 $ 1,958 $ 2,262

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Data	The following table shows selected quarterly data for the periods presented ( in thousands ): December 31, September 27, June 28, March 29, 2020 2020 2020 2020 Revenues $ 787,833 $ 666,240 $ 643,303 $ 617,253 Costs of revenues 623,390 512,877 496,678 465,208 Operating income 20,482 28,532 34,295 7,457 Net (loss) income $ (8,913) $ 10,731 $ 16,786 $ (4,777) December 31, September 29, June 30, March 31, 2019 2019 2019 2019 Revenues $ 697,085 $ 697,717 $ 695,607 $ 673,484 Costs of revenues 559,940 565,703 540,772 517,159 Operating (loss) income (3,167) (10,525) 26,158 14,353 Net (loss) income $ (16,664) $ (31,625) $ 3,388 $ (5,160)

Description of Business - Narra

Description of Business - Narrative (Details)	12 Months Ended
	Dec. 31, 2020segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2

Significant Accounting Princi_3

Significant Accounting Principles and Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Product Information [Line Items]
Impairment of long-lived assets	$ 0	$ 0	$ 0
Impairment of equity method investments	$ 0	$ 0	$ 0
U.S. Government Agencies | Accounts Receivable | Customer Concentration Risk
Product Information [Line Items]
Concentration risk (as a percent)	91.40%	96.00%
U.S. Government Agencies | Revenue Benchmark | Customer Concentration Risk
Product Information [Line Items]
Concentration risk (as a percent)	90.00%	93.00%
Minimum
Product Information [Line Items]
Customer account due period (in days)	30 days
Minimum | Machinery and equipment
Product Information [Line Items]
Useful life of property and equipment (in years)	4 years
Minimum | Computer and equipment
Product Information [Line Items]
Useful life of property and equipment (in years)	3 years
Minimum | Transportation equipment
Product Information [Line Items]
Useful life of property and equipment (in years)	4 years
Minimum | Furniture and fixtures
Product Information [Line Items]
Useful life of property and equipment (in years)	5 years
Minimum | Leasehold improvements
Product Information [Line Items]
Useful life of property and equipment (in years)	3 years
Maximum
Product Information [Line Items]
Customer account due period (in days)	45 days
Maximum | Machinery and equipment
Product Information [Line Items]
Useful life of property and equipment (in years)	20 years
Maximum | Computer and equipment
Product Information [Line Items]
Useful life of property and equipment (in years)	7 years
Maximum | Transportation equipment
Product Information [Line Items]
Useful life of property and equipment (in years)	11 years
Maximum | Furniture and fixtures
Product Information [Line Items]
Useful life of property and equipment (in years)	12 years
Maximum | Leasehold improvements
Product Information [Line Items]
Useful life of property and equipment (in years)	16 years

Significant Accounting Princi_4

Significant Accounting Principles and Policies - Amortization Period of Acquired Intangibles (Details)	12 Months Ended
	Dec. 31, 2020
Minimum | Customer relationships
Product Information [Line Items]
Amortization period of acquired intangibles	6 years
Minimum | Technology
Product Information [Line Items]
Amortization period of acquired intangibles	3 years
Minimum | Trade name
Product Information [Line Items]
Amortization period of acquired intangibles	5 years
Maximum | Customer relationships
Product Information [Line Items]
Amortization period of acquired intangibles	13 years
Maximum | Technology
Product Information [Line Items]
Amortization period of acquired intangibles	5 years
Maximum | Trade name
Product Information [Line Items]
Amortization period of acquired intangibles	10 years

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details)	Oct. 19, 2020USD ($)
Secured Debt | Term Loan Facility Maturing October 2027
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 740,000,000
Secured Debt | Delayed Draw Term Loan Facility Maturing October 2027
Debt Instrument [Line Items]
Maximum borrowing capacity	150,000,000
Revolving Credit Facility | Delayed Draw Term Loan Facility Maturing October 2027
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 175,000,000

Revenues - Disaggregated Revenu

Revenues - Disaggregated Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 787,833	$ 666,240	$ 643,303	$ 617,253	$ 697,085	$ 697,717	$ 695,607	$ 673,484	$ 2,714,628	$ 2,763,893	$ 2,608,562
United States
Disaggregation of Revenue [Line Items]
Revenues									1,731,497	1,748,471	1,648,988
International
Disaggregation of Revenue [Line Items]
Revenues									983,131	1,015,422	959,574
Cost-reimbursable
Disaggregation of Revenue [Line Items]
Revenues									1,348,891	1,312,070	1,319,768
Fixed-price
Disaggregation of Revenue [Line Items]
Revenues									946,244	1,003,961	876,986
Time and materials
Disaggregation of Revenue [Line Items]
Revenues									419,493	447,862	411,808
GMS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									2,080,474	2,099,737	1,968,843
GMS | United States | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									1,104,536	1,090,765	1,013,830
GMS | International | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									975,938	1,008,972	955,013
GMS | Cost-reimbursable | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									1,182,865	1,206,710	1,229,707
GMS | Fixed-price | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									676,714	717,595	595,127
GMS | Time and materials | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									220,895	175,432	144,009
NSS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									634,154	664,156	639,719
NSS | United States | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									626,961	657,706	635,158
NSS | International | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									7,193	6,450	4,561
NSS | Cost-reimbursable | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									166,026	105,360	90,061
NSS | Fixed-price | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									269,530	286,366	281,859
NSS | Time and materials | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									198,598	272,430	267,799
DoD
Disaggregation of Revenue [Line Items]
Revenues									1,084,856	1,081,601	989,936
DoD | GMS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									807,722	858,623	784,532
DoD | NSS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									277,134	222,978	205,404
Other U.S. government agencies
Disaggregation of Revenue [Line Items]
Revenues									1,343,530	1,483,140	1,456,170
Other U.S. government agencies | GMS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									1,079,345	1,123,459	1,096,193
Other U.S. government agencies | NSS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									264,185	359,681	359,977
Commercial and non-U.S. customers
Disaggregation of Revenue [Line Items]
Revenues									286,242	199,152	162,456
Commercial and non-U.S. customers | GMS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									193,407	117,655	88,118
Commercial and non-U.S. customers | NSS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									$ 92,835	$ 81,497	$ 74,338

Revenues - Narrative (Details)

Revenues - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Remaining performance obligations balance	$ 1,722	$ 1,640
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue recognized (as a percent)	95.40%
Expected period of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected revenue recognized (as a percent)	4.60%
Expected period of satisfaction	1 year

Contract Assets and Contract _3

Contract Assets and Contract Liabilities - Components of Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract assets	$ 360,552	$ 295,103
Contract liabilities	$ 106,475	$ 51,439

Contract Assets and Contract _4

Contract Assets and Contract Liabilities - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Increase (decrease) in contract assets	$ 65.4
Increase (decrease) in contract liabilities	55
Recognition of contract liabilities	$ 35.2	$ 19.1

Business Combinations and Acq_3

Business Combinations and Acquisitions - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 23, 2020	Nov. 20, 2020	Feb. 10, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Common stock par value (in dollars per share)				$ 0.0001	$ 0.0001	$ 0.0001
Goodwill				$ 590,668	$ 590,668	$ 409,588	$ 408,025
PE Shay Holdings, LLC
Business Acquisition [Line Items]
Post-closing adjustment, payment to management				20,200
PAE Management
Business Acquisition [Line Items]
Post-closing adjustment, payment to management				$ 1,000
Class A Common Stock
Business Acquisition [Line Items]
Common stock par value (in dollars per share)				$ 0.0001	$ 0.0001
Shay Holding Corporation Merger
Business Acquisition [Line Items]
Aggregate cash consideration paid			$ 424,200
Shay Holding Corporation Merger | Earn-Out Shares
Business Acquisition [Line Items]
Period following completion of business combination (in years)			5 years
Shay Holding Corporation Merger | Additional Paid-in Capital
Business Acquisition [Line Items]
Acquisition fees and expenses				$ 20,900	$ 20,900
Shay Holding Corporation Merger | Class A Common Stock
Business Acquisition [Line Items]
Consideration paid (in shares)			21,127,823
Shay Holding Corporation Merger | Class A Common Stock | Earn-Out Shares
Business Acquisition [Line Items]
Maximum additional earn-out (in shares)			4,000,000
CENTRA
Business Acquisition [Line Items]
Outstanding capital stock acquired (as a percent)		100.00%
Business combination, consideration transferred		$ 225,300
Goodwill		$ 125,113
Revenue recognized					31,500
Metis Solution
Business Acquisition [Line Items]
Outstanding capital stock acquired (as a percent)	100.00%
Business combination, consideration transferred	$ 95,700
Goodwill	$ 55,967
Revenue recognized					$ 7,600

Business Combinations and Acq_4

Business Combinations and Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Nov. 23, 2020	Nov. 20, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 590,668			$ 409,588	$ 408,025
CENTRA
Business Acquisition [Line Items]
Cash and cash equivalents			$ 3,202
Accounts receivable			72,636
Prepaid expenses and other current assets			3,454
Property and equipment			2,848
Operating lease right-of-use assets			21,137
Intangible assets			74,100
Total assets acquired			177,377
Accounts payable			30,212
Accrued expenses			1,159
Customer advances and billings in excess of costs			2,965
Salaries, benefits and payroll taxes			7,969
Deferred income taxes			12,402
Operating lease liabilities, current portion			2,996
Other current liabilities			1,423
Long-term operating lease liabilities			18,038
Total liabilities assumed			77,164
Net identifiable assets acquired			100,213
Goodwill			125,113
Total estimated consideration transferred			$ 225,326
Metis Solution
Business Acquisition [Line Items]
Cash and cash equivalents		$ 5,469
Accounts receivable		15,905
Prepaid expenses and other current assets		621
Property and equipment		27
Operating lease right-of-use assets		599
Intangible assets		37,800
Other noncurrent assets		63
Total assets acquired		60,484
Accounts payable		2,454
Accrued expenses		1,056
Customer advances and billings in excess of costs		3,420
Salaries, benefits and payroll taxes		5,486
Deferred income taxes		7,700
Operating lease liabilities, current portion		355
Long-term operating lease liabilities		240
Total liabilities assumed		20,711
Net identifiable assets acquired		39,773
Goodwill		55,967
Total estimated consideration transferred		$ 95,740

Business Combinations and Acq_5

Business Combinations and Acquisitions - Schedule of Intangible Assets Acquired (Details) - USD ($) $ in Thousands	Nov. 23, 2020	Nov. 20, 2020
CENTRA
Business Acquisition [Line Items]
Weighted-average Amortization Period		10 years
Fair Value		$ 74,100
CENTRA | Customer relationships
Business Acquisition [Line Items]
Weighted-average Amortization Period		10 years
Fair Value		$ 71,800
CENTRA | Trade Name & Trademarks
Business Acquisition [Line Items]
Weighted-average Amortization Period		7 years
Fair Value		$ 2,300
Metis Solution
Business Acquisition [Line Items]
Weighted-average Amortization Period	10 years
Fair Value	$ 37,800
Metis Solution | Customer relationships
Business Acquisition [Line Items]
Weighted-average Amortization Period	11 years
Fair Value	$ 32,200
Metis Solution | Trade Name & Trademarks
Business Acquisition [Line Items]
Weighted-average Amortization Period	7 years
Fair Value	$ 5,600

Accounts Receivable, net - Comp

Accounts Receivable, net - Components of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Billed receivables	$ 227,787	$ 148,747
Unbilled receivables	360,552	295,103
Less allowance for credit losses	(2,828)	(1,670)
Total accounts receivables, net	$ 585,511	$ 442,180

Accounts Receivable, net - Narr

Accounts Receivable, net - Narrative (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable | U.S. Government Agencies | Customer Concentration Risk
Product Information [Line Items]
Concentration risk (as a percent)	91.40%	96.00%

Property and Equipment, net - C

Property and Equipment, net - Components of Property and Equipment, net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 78,847	$ 73,952
Less accumulated depreciation and amortization	(51,232)	(43,548)
Total property and equipment, net	27,615	30,404
Assets not yet in service
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,111	301
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,906	9,823
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,839	12,094
Computer and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	36,119	34,894
Transportation equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	13,519	14,043
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,353	$ 2,797

Property and Equipment, net - N

Property and Equipment, net - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 9.6	$ 12.9	$ 14.5

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, net - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Other	$ 0
Amortization of intangible assets	$ 34,154,000	$ 33,205,000	$ 35,780,000
Customer relationships | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets (in years)	8 years 2 months 12 days	7 years 10 months 24 days
Trade name | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Useful life of finite-lived intangible assets (in years)	5 years 10 months 24 days	6 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, net - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Beginning balance	$ 409,588	$ 408,025
Acquisitions	181,080	0
Other	0	1,563
Ending balance	590,668	409,588
GMS
Goodwill [Roll Forward]
Beginning balance	208,593	208,593
Acquisitions	0	0
Other	0	0
Ending balance	208,593	208,593
NSS
Goodwill [Roll Forward]
Beginning balance	200,995	199,432
Acquisitions	181,080	0
Other	0	1,563
Ending balance	$ 382,075	$ 200,995

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, net - Intangible Assets, net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 417,400	$ 305,500
Accumulated Amortization	(159,190)	(125,036)
Total	258,210	180,464
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	390,900	286,900
Accumulated Amortization	(149,163)	(116,923)
Total	241,737	169,977
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,700	1,700
Accumulated Amortization	(1,700)	(1,700)
Total	0	0
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	24,800	16,900
Accumulated Amortization	(8,327)	(6,413)
Total	$ 16,473	$ 10,487

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets, net - Estimated Amortization Expense in Future Years (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 50,106
2022	50,089
2023	40,666
2024	33,782
2025	28,015
Thereafter	55,552
Total	$ 258,210	$ 180,464

Consolidated Variable Interes_3

Consolidated Variable Interest Entities - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Total assets	$ 1,829,370	$ 1,371,299
Liabilities and stockholders’ equity
Total liabilities	1,672,718	1,383,208
Total equity	124,416	(43,760)
Total liabilities and equity	1,829,370	1,371,299
Variable Interest Entity, Primary Beneficiary
Assets
Total assets	145,664	127,742
Liabilities and stockholders’ equity
Total liabilities	96,318	80,151
Total equity	49,346	47,591
Total liabilities and equity	$ 145,664	$ 127,742

Consolidated Variable Interes_4

Consolidated Variable Interest Entities - Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Revenues	$ 787,833	$ 666,240	$ 643,303	$ 617,253	$ 697,085	$ 697,717	$ 695,607	$ 673,484	$ 2,714,628	$ 2,763,893	$ 2,608,562
Cost of revenues	$ 623,390	$ 512,877	$ 496,678	$ 465,208	$ 559,940	$ 565,703	$ 540,772	$ 517,159	2,098,153	2,183,574	1,991,622
Selling, general and administrative expenses									498,827	530,080	536,019
Total operating expenses									2,631,134	2,746,859	2,563,421
Program profit									83,494	17,034	45,141
Other income (loss), net									7,272	9,785	4,980
Net income (loss)									15,290	(49,809)	(34,459)
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Revenues									369,966	340,063	259,386
Cost of revenues									301,345	311,310	205,730
Selling, general and administrative expenses									73,400	80,942	84,473
Total operating expenses									374,745	392,252	290,203
Program profit									(4,779)	(52,189)	(30,817)
Other income (loss), net									908	(1,697)	(1,093)
Net income (loss)									$ (3,871)	$ (53,886)	$ (31,910)

Other current liabilities - Oth

Other current liabilities - Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Liabilities Disclosure [Abstract]
Reserves	$ 13,617	$ 11,659
Accrued foreign taxes	13,227	6,053
Accrued losses on contracts	11,455	11,352
Other	6,738	1,829
Other current liabilities	$ 45,037	$ 30,893

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total debt	$ 890,000	$ 772,101
Unamortized discount and debt issuance costs	(23,733)	(22,164)
Total debt, net of discount and debt issuance costs	866,267	749,937
Less current maturities of long-term debt	(5,961)	(22,007)
Total long-term debt, net of current	860,306	727,930
Secured Debt | First Term Loan
Debt Instrument [Line Items]
Total debt	890,000	506,772
Secured Debt | Second Term Loan
Debt Instrument [Line Items]
Total debt	0	265,329
Line of Credit | Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	$ 0	$ 0

Debt - Narrative (Details)

Debt - Narrative (Details)	Oct. 19, 2020USD ($)	Oct. 20, 2016	Dec. 31, 2020USD ($)letter_of_credit	Dec. 31, 2019USD ($)letter_of_credit	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Loss on extinguishment of debt			$ 16,528,000	$ 0	$ 0
Number of letters of credit outstanding | letter_of_credit			13	11
Letters of credit outstanding, amount			$ 23,900,000	$ 21,200,000
Base Rate | Variable Rate Component One
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.50%
London Interbank Offered Rate (LIBOR) | Addition to LIBO Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.00%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.80%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.30%
First Term Loan
Debt Instrument [Line Items]
Debt issuance costs, gross			13,200,000
Loss on extinguishment of debt			12,500,000
First Term Loan | Secured Debt
Debt Instrument [Line Items]
Debt instrument, face amount	$ 890,000,000		$ 484,400,000
Debt instrument, interest rate during period (as a percent)			5.30%	7.40%
First Term Loan | Base Rate | Secured Debt
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		4.50%
First Term Loan | London Interbank Offered Rate (LIBOR) | Secured Debt
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		3.50%
Term Loan Facility Maturing October 2027 | Secured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 740,000,000
Term Loan Facility Maturing October 2027 | Secured Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	4.50%
Delayed Draw Term Loan Facility Maturing October 2027 | Secured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 150,000,000
Delayed Draw Term Loan Facility Maturing October 2027 | Secured Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	4.50%
Delayed Draw Term Loan Facility Maturing October 2027 | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 175,000,000
Revolving Credit Facility | Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Remaining borrowing capacity			$ 132,800,000	$ 121,800,000
Applicable interest rate (as a percent)			4.00%	5.80%
Revolving Credit Facility | Revolving Credit Facility | Base Rate | Minimum | Line of Credit
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.80%
Revolving Credit Facility | Revolving Credit Facility | Base Rate | Maximum | Line of Credit
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.30%
Revolving Credit Facility | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum | Line of Credit
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.80%
Revolving Credit Facility | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum | Line of Credit
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.30%
Second Term Loan | Secured Debt
Debt Instrument [Line Items]
Debt instrument, face amount			$ 128,800,000
Debt instrument, interest rate during period (as a percent)				11.40%

Debt - Future Principal Maturit

Debt - Future Principal Maturities of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
2021	$ 8,900
2022	8,900
2023	8,900
2024	8,900
2025	8,900
Thereafter	845,500
Total debt	$ 890,000	$ 772,101

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - $ / shares	Feb. 10, 2020	Dec. 31, 2020	Apr. 03, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capital stock authorized (in shares)		211,000,000
Common stock par value (in dollars per share)		$ 0.0001		$ 0.0001
Preferred stock par value (in dollars per share)		$ 0.0001		$ 0.0001
Common stock authorized (in shares)		210,000,000		210,000,000
Preferred stock authorized (in shares)		1,000,000		1,000,000
Class of warrant or right, outstanding (in shares)		19,999,985
Shay Holding Corporation Merger | Earn-Out Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period following completion of business combination (in years)	5 years
Shay Holding Corporation Merger | Earn-Out Shares, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum additional earn-out (in shares)		1,000,000
Share price threshold (in dollars per share)		$ 13
Shay Holding Corporation Merger | Earn-Out Shares, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum additional earn-out (in shares)		1,000,000
Share price threshold (in dollars per share)		$ 15.50
Shay Holding Corporation Merger | Earn-Out Shares, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum additional earn-out (in shares)		1,000,000
Share price threshold (in dollars per share)		$ 18
Shay Holding Corporation Merger | Earn-Out Shares, Tranche Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum additional earn-out (in shares)		1,000,000
Share price threshold (in dollars per share)		$ 20.50
Public Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Redeemable price of warrants or rights (in dollars per share)		0.01
Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Redeemable price of warrants or rights (in dollars per share)		0.01
Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock par value (in dollars per share)		$ 0.0001
Number of securities called by each warrant or right (in shares)		1
Exercise price of warrants or rights (in dollars per shares)		$ 11.50
Expiration period of warrants (in years)		5 years
Class A Common Stock | Shay Holding Corporation Merger | Earn-Out Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum additional earn-out (in shares)	4,000,000
Minimum threshold trading days		10 days
Consecutive trading days		20 days
Class A Common Stock | Public Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, outstanding (in shares)		13,333,319	13,333,333
Class A Common Stock | Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of warrant or right, outstanding (in shares)		6,666,666	6,666,666
Share price threshold (in dollars per share)		$ 18
Number of trading days		20 days
Trading day period		30 days

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ in Millions	Feb. 09, 2020	Dec. 31, 2020
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 1.1
2016 Participation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 17.4
2020 Incentive Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 11.9
Grants issued during period (in shares)		2,639,920
Compensation cost related to non-vested awards not yet recognized		$ 7.4
Non-vested awards not yet recognized, weighted-average period (in years)		1 year 7 months 6 days
2020 Incentive Plan | Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award performance weight (as a percent)		50.00%
2020 Incentive Plan | Restricted Stock Units (RSUs) | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants issued during period (in shares)		2,639,920
2020 Incentive Plan | Restricted Stock Units (RSUs) | Employees | Shay Holding Corporation Merger
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants issued during period (in shares)		1,581,960
2020 Incentive Plan | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants issued during period (in shares)		631,219
Compensation cost related to non-vested awards not yet recognized		$ 4.1
Non-vested awards not yet recognized, weighted-average period (in years)		2 years
Award vesting period		3 years
2020 Incentive Plan | Performance Shares | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants issued during period (in shares)		631,219

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of RSUs and PSUs (Details) - 2020 Incentive Plan	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Restricted Stock Units (RSUs)
Shares
Beginning balance (in shares) | shares	0
Granted (in shares) | shares	2,639,920
Vested (in shares) | shares	(34,366)
Forfeited (in shares) | shares	(44,721)
Ending balance (in shares) | shares	2,560,833
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 0
Granted (in dollars per share) | $ / shares	7.45
Vested (in dollars per share) | $ / shares	8.33
Forfeited (in dollars per share) | $ / shares	7.56
Ending balance (in dollars per share) | $ / shares	$ 7.92
Performance Shares
Shares
Beginning balance (in shares) | shares	0
Granted (in shares) | shares	631,219
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(22,082)
Ending balance (in shares) | shares	609,137
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 0
Granted (in dollars per share) | $ / shares	8.63
Vested (in dollars per share) | $ / shares	0
Forfeited (in dollars per share) | $ / shares	9.26
Ending balance (in dollars per share) | $ / shares	$ 9.28

Net Income (Loss) Per Share - C

Net Income (Loss) Per Share - Computation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income (loss) attributed to PAE Incorporated	$ 15,290	$ (49,809)	$ (34,459)
Denominator:
Basic weighted average shares (in shares)	84,114,016	21,127,823	21,127,823
Diluted weighted average shares (in shares)	85,369,328	21,127,823	21,127,823
Basic income (loss) per share (in dollars per share)	$ 0.18	$ (2.36)	$ (1.63)
Diluted income (loss) per share (in dollars per share)	$ 0.18	$ (2.36)	$ (1.63)

Net Income (Loss) Per Share - N

Net Income (Loss) Per Share - Narrative (Details)	12 Months Ended
	Dec. 31, 2020shares
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted loss per share (in shares)	19,999,985
Earn-Out Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted loss per share (in shares)	4,000,000

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease right-of-use assets, net	$ 191,370	$ 162,184
Operating lease liabilities	192,349
Operating lease cost	$ 55,700	$ 50,000
Weighted average remaining lease term (in years)	7 years
Weighted average discount rate (as a percent)	6.20%
Cash payments for operating leases	$ 44,000

Leases - Future Minimum Operati

Leases - Future Minimum Operating Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 48,547
2022	42,234
2023	37,212
2024	29,009
2025	22,558
Thereafter	54,509
Total future minimum lease payments	234,069
Less imputed interest	41,720
Present value of minimum lease payments	192,349
Less current maturities of lease liabilities	46,756	$ 36,997
Long-term lease liabilities	$ 145,593

Segment Reporting - Information

Segment Reporting - Information by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 787,833	$ 666,240	$ 643,303	$ 617,253	$ 697,085	$ 697,717	$ 695,607	$ 673,484	$ 2,714,628	$ 2,763,893	$ 2,608,562
Operating income (loss)	$ 20,482	$ 28,532	$ 34,295	$ 7,457	$ (3,167)	$ (10,525)	$ 26,158	$ 14,353	90,766	26,819	50,121
Amortization of intangible assets									34,154	33,205	35,780
Corporate
Segment Reporting Information [Line Items]
Revenues									0	0	0
Operating income (loss)									(11,397)	(28,627)	(26,464)
Amortization of intangible assets									0	0	0
GMS | Operating Segments
Segment Reporting Information [Line Items]
Revenues									2,080,474	2,099,737	1,968,843
Operating income (loss)									80,090	92,386	89,141
Amortization of intangible assets									16,461	16,679	18,492
NSS | Operating Segments
Segment Reporting Information [Line Items]
Revenues									634,154	664,156	639,719
Operating income (loss)									22,073	(36,940)	(12,556)
Amortization of intangible assets									$ 17,693	$ 16,526	$ 17,288

Related-Party Transactions - Na

Related-Party Transactions - Narrative (Details) - USD ($) $ in Millions	Feb. 10, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
PE Shay Holdings, LLC
Related Party Transaction [Line Items]
Liability for estimated payment to platinum stockholder		$ 4.7
Affiliated Entity | Advisory Services
Related Party Transaction [Line Items]
Related party transaction expenses	$ 15	$ 15.8	$ 5.1	$ 5
Affiliated Entity | Advisory Services | Selling, General and Administrative Expenses
Related Party Transaction [Line Items]
Related party transaction expenses	$ 0.8

Other Income, Net - Components

Other Income, Net - Components of Other Income, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income and Expenses [Abstract]
Net earnings (loss) of equity method investments	$ 6,082	$ 2,454	$ (180)
Gain on sale of fixed assets and other	1,190	7,331	5,160
Total	$ 7,272	$ 9,785	$ 4,980

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Tax Credit Carryforward [Line Items]
Tax expense (benefit) on increased interest expense deduction	$ 2,400
Payroll tax funding deferral	37,000
State income tax (benefit) expense	1,100	$ (100)	$ (1,300)
Valuation allowance	12,050	13,784
Unrecognized tax benefits	12,300	6,100	6,800
Interest and penalties	5,100	4,200	4,500
Decrease in unrecognized tax benefits is reasonably possible	3,100
Work Opportunity Tax Credit
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	1,000
Net Portion of Deferred Tax Asset Likely to be Realized
Tax Credit Carryforward [Line Items]
Valuation allowance	4,200
Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	36,000	35,600	33,100
Income taxes receivable	5,000	5,000	13,600
Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	8,800
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	$ 77,100	$ 77,700	$ 73,400

Income Taxes - Domestic and For

Income Taxes - Domestic and Foreign Components of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Domestic	$ (80,255)	$ (141,068)	$ (94,924)
Foreign	97,164	81,876	60,685
Income (loss) before income taxes	$ 16,909	$ (59,192)	$ (34,239)

Income Taxes - Components of Pr

Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current
Federal	$ 1,414	$ 0	$ 0
State	0	0	0
Foreign	9,035	6,507	6,991
Total current expense (benefit)	10,449	6,507	6,991
Deferred
Federal	(7,366)	(15,638)	(9,652)
State	0	0	0
Foreign	0	0	0
Total deferred (benefit) expense	(7,366)	(15,638)	(9,652)
Provision for income taxes	$ 3,083	$ (9,131)	$ (2,661)

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Amount computed at statutory federal income tax rate	$ 3,785	$ (12,452)	$ (7,471)
Increases (decreases) in tax resulting from:
CARES Act adjustment	(2,435)	0	0
Section 250 Deduction	(2,834)	(2,682)	(743)
Non taxable income	(2,868)	(1,071)	(1,049)
Non deductible compensation	1,735	0	0
Change in valuation allowance	4,180	5,601	7,026
Effect of foreign operations	87	135	505
Change in Uncertain tax position	2,272	237	553
Minority Interest	748	552	(29)
Transaction costs	(865)	0	0
Other permanent differences, net	(722)	549	(1,453)
Provision for income taxes	$ 3,083	$ (9,131)	$ (2,661)

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets
Accrued compensation benefits	$ 14,416	$ 8,204
Reserves	5,171	4,670
Net operating loss and credit carryover	4,877	3,202
Foreign tax credit carryover	35,981	35,629
Tax reserve benefit	5,409	3,916
Interest carryover	2,080	16,438
Operating lease liability	43,280	39,283
Other	4,722	4,846
Total deferred tax assets	115,936	116,188
Valuation allowance	(12,050)	(13,784)
Net deferred tax assets	103,886	102,404
Deferred tax liabilities
Depreciation	(4,087)	(4,384)
Prepaid expenses	(3,341)	(1,779)
Unbilled receivables	(2,178)	(22,958)
Intangible assets	(54,908)	(31,480)
Operating lease right-of-use assets	(43,034)	(37,540)
Investment in unconsolidated foreign subsidiary	(727)	(1,051)
Total deferred tax liabilities	(108,275)	(99,192)
Deferred Tax Liabilities, Net	$ (4,389)
Net deferred tax assets (liabilities)		$ 3,212

Income Taxes - Changes in Unrec

Income Taxes - Changes in Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning of the year	$ 1,958	$ 2,262	$ 3,614
Additions and (subtractions) on position taken during current year	3,799		0
Additions and (subtractions) on position taken during current year		(304)
Additions and (subtractions) on position taken in prior periods	1,478	0	0
Reductions due to settlements	0	0	(1,352)
End of the year	$ 7,235	$ 1,958	$ 2,262

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) - Selected Quarterly Data (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 787,833	$ 666,240	$ 643,303	$ 617,253	$ 697,085	$ 697,717	$ 695,607	$ 673,484	$ 2,714,628	$ 2,763,893	$ 2,608,562
Cost of revenues	623,390	512,877	496,678	465,208	559,940	565,703	540,772	517,159	2,098,153	2,183,574	1,991,622
Operating (loss) income	20,482	28,532	34,295	7,457	(3,167)	(10,525)	26,158	14,353	90,766	26,819	50,121
Net (loss) income	$ (8,913)	$ 10,731	$ 16,786	$ (4,777)	$ (16,664)	$ (31,625)	$ 3,388	$ (5,160)	$ 13,826	$ (50,061)	$ (31,578)

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - Parsons Government Services, Inc. $ in Millions	Jan. 31, 2021USD ($)
Subsequent Event [Line Items]
Minority interest (as a percent)	49.00%
Payments to acquire equity method investments	$ 15.8
Ownership percentage (as a percent)	100.00%