Parsons (PSN) 10-Q 18 Jun 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Jun. 06, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	PSN
Entity Registrant Name	Parsons Corporation
Entity Central Index Key	0000275880
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		99,434,877

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents (including $73,794 and $42,872 Cash of consolidated joint ventures)	$ 121,408	$ 280,221
Restricted cash and investments	9,061	974
Accounts receivable, net (including $180,325 and $193,597 Accounts receivable of consolidated joint ventures, net)	651,924	623,286
Contract assets (including $21,270 and $23,964 Contract assets of consolidated joint ventures)	571,755	515,319
Prepaid expenses and other current assets (including $11,837 and $9,423 Prepaid expenses and other current assets of consolidated joint ventures)	77,013	69,007
Total current assets	1,431,161	1,488,807
Property and equipment, net (including $2,561 and $2,507 Property and equipment of consolidated joint ventures, net)	97,298	91,849
Right of use assets, operating leases	216,484	0
Goodwill	921,097	736,938
Investments in and advances to unconsolidated joint ventures	67,202	63,560
Intangible assets, net	250,948	179,519
Deferred tax assets	4,891	5,680
Other noncurrent assets	43,917	46,225
Total assets	3,032,998	2,612,578
Current liabilities:
Accounts payable (including $87,914 and $91,505 Accounts payable of consolidated joint ventures)	203,684	226,345
Accrued expenses and other current liabilities (including $73,209 and $71,593 Accrued expenses and other current liabilities of consolidated joint ventures)	547,954	559,700
Contract liabilities (including $38,706 and $46,754 Contract liabilities of consolidated joint ventures)	225,017	208,576
Short-term lease liabilities, operating leases	53,029	0
Income taxes payable	9,415	11,540
Short-term notes payable	149,786	0
Total current liabilities	1,188,885	1,006,161
Long-term employee incentives	29,991	41,913
Deferred gain resulting from sale-leaseback transactions	0	46,004
Long-term debt	509,211	429,164
Long-term lease liabilities, operating leases	181,274	0
Deferred tax liabilities	7,922	6,240
Other long-term liabilities	111,023	127,863
Total liabilities	2,028,306	1,657,345
Commitments and contingencies (Note 14)
Redeemable common stock held by Employee Stock Ownership Plan (ESOP) ,$1 par value; authorized 150,000,000 shares; 125,097,684 shares issued; 78,172,809 and 78,138,831 shares outstanding, recorded at redemption value	1,875,332	1,876,309
Shareholder's equity (deficit):
Treasury Stock, 46,918,140 and 46,958,853 shares at cost	(957,838)	(957,025)
Retained earnings	75,771	12,445
Accumulated other comprehensive loss	(20,401)	(22,957)
Total Parsons Corporation shareholder's equity (deficit)	(902,468)	(967,537)
Noncontrolling interests	31,828	46,461
Total shareholder's equity (deficit)	(870,640)	(921,076)
Total liabilities, redeemable common stock and shareholder's equity (deficit)	$ 3,032,998	$ 2,612,578

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Cash and cash equivalents	$ 121,408	$ 280,221
Accounts receivable, net	651,924	623,286
Contract assets	571,755	515,319
Prepaid expenses and other current assets	77,013	69,007
Property and equipment, net	97,298	91,849
Accounts payable	203,684	226,345
Accrued expenses and other current liabilities	547,954	559,700
Contract liabilities	$ 225,017	$ 208,576
Temporary equity, par value	$ 1	$ 1
Temporary equity, shares authorized	150,000,000	150,000,000
Temporary equity, shares issued	125,097,684	125,097,684
Temporary equity, shares outstanding	78,138,831	78,172,809
Treasury stock, shares	46,958,853	46,918,140
Consolidated Joint Ventures
Cash and cash equivalents	$ 42,872	$ 73,794
Accounts receivable, net	193,597	180,325
Contract assets	23,964	21,270
Prepaid expenses and other current assets	9,423	11,837
Property and equipment, net	2,507	2,561
Accounts payable	91,505	87,914
Accrued expenses and other current liabilities	71,593	73,209
Contract liabilities	$ 46,754	$ 38,706

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Income Statement [Abstract]
Revenues	$ 904,405	$ 754,679
Direct costs of contracts	714,237	602,972
Equity in earnings of unconsolidated joint ventures	10,397	11,031
Indirect, general and administrative expenses	177,519	123,847
Operating income	23,046	38,891
Interest income	477	741
Interest expense	(8,292)	(3,999)
Other income, net	41	1,152
(Interest and other expense) gain associated with claim on long-term contract	0	(2,330)
Total other expense	(7,774)	(4,436)
Income before income tax provision	15,272	34,455
Income tax provision	(1,886)	(5,353)
Net income including noncontrolling interests	13,386	29,102
Net income attributable to noncontrolling interests	(3,645)	(3,815)
Net income attributable to Parsons Corporation	$ 9,741	$ 25,287
Earnings per share:
Basic and diluted	$ 0.12	$ 0.31

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income including noncontrolling interests	$ 13,386	$ 29,102
Other comprehensive (loss) income, net of tax
Foreign currency translation adjustment, net of tax	2,549	(2,784)
Pension adjustments, net of tax	9	(19)
Comprehensive income including noncontrolling interests, net of tax	15,944	26,299
Comprehensive income attributable to noncontrolling interests, net of tax	(3,645)	(3,815)
Comprehensive income attributable to Parsons Corporation, net of tax	$ 12,299	$ 22,484

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Cash flows from operating activities:
Net income including noncontrolling interests	$ 13,386	$ 29,102
Adjustments to reconcile net income to net cash used in operating activities
Depreciation and amortization	30,591	9,009
Amortization of deferred gain	0	(1,813)
Amortization of debt issue costs	244	149
(Gain) loss on disposal of property and equipment	(27)	18
Provision for doubtful accounts	(279)	2,426
Deferred taxes	1,486	(138)
Foreign currency transaction gains and losses	618	(457)
Equity in earnings of unconsolidated joint ventures	(10,397)	(11,031)
Return on investments in unconsolidated joint ventures	10,794	15,406
Contributions of treasury stock	12,250	11,357
Changes in assets and liabilities, net of acquisitions and newly consolidated joint ventures:
Accounts receivable	(17,135)	469,720
Contract assets	(46,984)	(531,157)
Prepaid expenses and current assets	(1,424)	(27,138)
Accounts payable	(28,182)	(723)
Accrued expenses and other current liabilities	(24,023)	(44,016)
Billings in excess of costs	0	(152,147)
Contract liabilities	14,884	299,639
Provision for contract losses	0	(143,666)
Income taxes	(3,645)	(597)
Other long-term liabilities	(12,265)	10,624
Net cash used in operating activities	(60,108)	(65,433)
Cash flows from investing activities:
Capital expenditures	(11,041)	(5,152)
Proceeds from sale of property and equipment	135	29
Payments for acquisitions, net of cash acquired	(287,482)	0
Investments in unconsolidated joint ventures	(4,905)	(3,058)
Return of investments in unconsolidated joint ventures	2,234	0
Net cash used in investing activities	(301,059)	(8,181)
Cash flows from financing activities:
Proceeds from borrowings under credit agreement	290,000	0
Repayments of borrowings under credit agreement	(60,000)	0
Payments for debt costs and credit agreement	(286)	0
Contributions by (distributions to) noncontrolling interests, net	(18,278)	6,497
Purchase of treasury stock	(813)	(366)
Net cash provided by financing activities	210,623	6,131
Effect of exchange rate changes	(182)	(825)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(150,726)	(68,308)
Cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash, beginning of period	281,195	446,144
Cash, cash equivalents and restricted cash, end of period	$ 130,469	$ 377,836

Consolidated Statements of Shar

Consolidated Statements of Shareholder's Equity (Unaudited) - USD ($) $ in Thousands	Total	Redeemable Common Stock	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total Parsons Deficit	Noncontrolling Interest
Beginning balance at Dec. 29, 2017	$ (1,049,916)		$ (876,372)	$ (186,035)	$ (15,003)	$ (1,077,410)	$ 27,494
Beginning balance, Temporary Equity at Dec. 29, 2017		$ 1,855,305
Comprehensive income
Net income including noncontrolling interests	29,102			25,287		25,287	3,815
Foreign currency translation gain (loss)	(2,784)				(2,781)	(2,781)	(3)
Pension adjustments, net of tax	(19)				(19)	(19)
Adjustment due to adoption of ASC | ASC 606	(4,632)			(4,735)		(4,735)	103
Purchase of treasury stock	0		(367)	367		0
Temporary equity, Purchase of treasury stock		(367)
Contributions, net of distributions	6,497					0	6,497
Ending Balance at Mar. 30, 2018	(1,021,752)		(876,738)	(165,116)	(17,803)	(1,059,658)	37,906
Ending Balance, Temporary Equity at Mar. 30, 2018		1,854,938
Beginning balance at Dec. 31, 2018	(921,076)		(957,025)	12,445	(22,957)	(967,537)	46,461
Beginning balance, Temporary Equity at Dec. 31, 2018	1,876,309	1,876,309
Comprehensive income
Net income including noncontrolling interests	13,386			9,741		9,741	3,645
Foreign currency translation gain (loss)	2,547				2,547	2,547	0
Pension adjustments, net of tax	9				9	9
Adjustment due to adoption of ASC | ASC 842	52,608			52,608		52,608	0
Purchase of treasury stock	0		(813)	813		0
Temporary equity, Purchase of treasury stock		(813)
Distributions, net of contributions	(18,278)					0	(18,278)
ESOP shares at redemption value	164			164		164
Temporary equity, ESOP shares at redemption value		(164)
Ending Balance at Mar. 31, 2019	(870,640)		$ (957,838)	$ 75,771	$ (20,401)	$ (902,468)	$ 31,828
Ending Balance, Temporary Equity at Mar. 31, 2019	$ 1,875,332	$ 1,875,332

Description of Operations

Description of Operations	3 Months Ended
	Mar. 31, 2019
Description Of Operations Disclosure [Abstract]
Description of Operations	1. Description of Operations Organization Parsons Corporation, a Delaware corporation, and its subsidiaries (collectively, the “Company”) provide sophisticated design, engineering and technical services, and smart and agile software to the United States federal government and Critical Infrastructure customers worldwide. The Company performs work in various foreign countries through local subsidiaries, joint ventures and foreign offices maintained to carry out specific projects. Parsons Employee Stock Ownership Plan (“ESOP”) is the sole shareholder of the Company. Initial Public Offering Effective May 8, 2019, the Company consummated its initial public offering (“IPO”) whereby the Company sold 18,518,500 shares of common stock for $27.00 per share. The underwriters exercised their share option effective May 14, 2019 to purchase an additional 2,777,775 shares at the share price of $25.515 which is the initial public offering share price of $27.00 less the underwriting discount of $1.485 per share. The net proceeds of the initial public offering and the underwriters’ share option was approximately $533.8 million, after deducting underwriting discounts and other fees, were used to fund an IPO dividend of $52.1 million, repay the outstanding balance of $150.0 million under our Term Loan, and repay outstanding indebtedness under our Revolving Credit Facility.

Basis of Presentation and Princ

Basis of Presentation and Principles of Consolidation	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation and Principles of Consolidation	2 . The accompanying unaudited consolidated financial statements and related notes of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") and pursuant to the interim period reporting requirements of Form 10-Q. They do not include all of the information and footnotes required by GAAP for complete financial statements and, therefore, should be read in conjunction with our consolidated financial statements and the notes thereto included in the Company’s Form S-1/A filed on April 29, 2019. In the opinion of management, the consolidated financial statements reflect all normal recurring adjustments necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. The results of operations and cash flows for any interim period are not necessarily indicative of results for the full year or for future years. This Quarterly Report on Form 10-Q includes the accounts of our wholly-owned subsidiaries, and joint ventures of which we are the primary beneficiary. The equity method of accounting is applied for the joint ventures in which the Company does not have a controlling interest, but exerts a significant influence (see “Note 16 – In the first quarter of 2019 the Company adopted Accounting Standards Update (‘ASU”) 2016-02, “Leases” (“Topic 842”), using the modified retrospective method. The new guidance was applied to leases that existed or were entered into on or after January 1. 2019. The Company’s results for the reporting period beginning January 1, 2019 have been presented under Topic 842, while prior period amounts have not been adjusted and continue to be reported in accordance with previous guidance. See “Note 6 – Leases” for further discussion of the adoption and the impact on the Company’s financial statements. Fiscal Periods In October 2018, our board of directors approved a change in our annual and quarterly fiscal period ends from the last Friday on or before the calendar year or quarterly month-end to the last day of the calendar year or quarterly month-end. Accordingly, the period end for the first quarters of fiscal 2018 and fiscal 2019 are March 30, 2018 and March 31, 2019, respectively. The number of days in the quarters ended March 30, 2018 and March 31, 2019 were 91 and 90, respectively. Use of Estimates The preparation of the consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual amounts could differ from those estimates. The Company’s most significant estimates and judgments involve revenue recognition with respect to the determination of the costs to complete contracts and transaction price; determination of self-insurance reserves; valuation of the Company’s fair value of common stock; useful lives of property and equipment and intangible assets; calculation of allowance for doubtful accounts; valuation of deferred income tax assets and uncertain tax positions, among others. Please refer to “Note 2 – Summary of Significant Accounting Policies” of Notes to Consolidated Financial Statements included in the Company’s Form S-1/A filed April 29, 2019, for a discussion of the significant estimates and assumptions affecting our consolidated financial statements. Estimates of costs to complete contracts are continually evaluated as work progresses and are revised when necessary. When a change in estimate is determined to have an impact on contract profit, the Company records a positive or negative adjustment to the consolidated statement of income.

Recently Adopted Accounting Pro

Recently Adopted Accounting Pronouncements	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Recently Adopted Accounting Pronouncements	3 . In the first quarter of 2019, the Company adopted Topic 842. See “Note 6 – Leases” for further discussion of the adoption and the impact on the Company’s financial statements. In the first quarter of 2019, the Company adopted ASU 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” under which the Company did not elect to reclassify the income tax effects stranded in accumulated other comprehensive income to retained earnings as a result of the enactment of comprehensive tax legislation, commonly referred to as the Tax Cuts and Jobs Act. As a result, there was no impact on the Company’s financial position, results of operations or cash flows. On December 30, 2017, the Company adopted ASC 606, “Revenue from Contracts with Customers”, using the modified retrospective method, which provides for a cumulative effect adjustment to retained earnings beginning in fiscal 2018 for those uncompleted contracts impacted by the adoption of the new standard. The difference between the recognition criteria under ASC 606 and our previous recognition practices under ASC 605-35 was recognized through a cumulative adjustment of $4.7 million that was made to the opening balance of accumulated deficit as of December 30, 2017. In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-04, Simplifying the Test for Goodwill Impairment. ASU 2017-04 simplifies the test for goodwill impairment by removing the second step of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The guidance is effective for interim and annual reporting periods beginning after December 15, 2019 and should be applied prospectively with early adoption permitted. The Company early adopted the new standard as of the beginning of fiscal 2018 and its adoption did not have a material impact on the consolidated financial statements.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Acquisitions	4 . Polaris Alpha On May 31, 2018, the Company acquired a 100% ownership interest in Polaris Alpha, a privately owned, advanced technology-focused provider of innovative mission solutions for complex defense, intelligence, and security customers, as well as other U.S. federal government customers, for $489.1 million paid in cash. The Company borrowed $260 million under the credit agreement, as described in “Note 12 – Debt and Credit Facilities,” to partially fund the acquisition. In connection with this acquisition, the Company recognized $6.2 million of acquisition-related expenses in “Indirect, general and administrative expense” in the consolidated statements of income for the fiscal year ended December 31, 2018, including legal fees, consulting fees, and other miscellaneous direct expenses associated with the acquisition. Polaris Alpha enhances the Company’s artificial intelligence and data analytics expertise with new technologies and solutions. Customers of both companies will benefit from existing, complementary technologies and increased scale, enabling end-to-end solutions under the shared vision of rapid prototyping and agile development. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on preliminary purchase price allocation as of the date of acquisition (in thousands): Amount Cash and cash equivalents $ 7,914 Accounts receivable 29,688 Contract assets 35,229 Prepaid expenses and other current assets 9,295 Property and equipment 9,024 Goodwill 243,471 Intangible assets 199,520 Other noncurrent assets 2,203 Accounts payable (13,942 ) Accrued expenses and other current liabilities (26,419 ) Contract liabilities (3,529 ) Deferred tax liabilities (2,231 ) Other long-term liabilities (1,146 ) Net assets acquired $ 489,077 Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years): Gross Carrying Amount Amortization Period (in years) Developed technology $ 84,900 4 Customer relationships 76,000 8 Backlog 34,900 2 Trade name 3,600 1 Leases $ 120 6 Amortization expense of $13.7 million related to these intangible assets was recorded for the three months ended March 31, 2019. The entire value of goodwill of $243.5 million was assigned to the Parsons Federal reporting unit and represents synergies expected to be realized from this business combination. A portion of goodwill is The amount of revenue generated by Polaris Alpha and included within consolidated revenues for the three months ended March 31, 2019 is $93.4 million. The Company has determined that the presentation of net income from the date of acquisition is impracticable due to the integration of general corporate functions upon acquisition. Supplemental Pro Forma Information (Unaudited) Supplemental information on an unaudited pro forma operating results assuming the Polaris Alpha acquisition had been consummated as of the beginning of fiscal year 2018 (December 31, 2017) (in thousands) is as follows: Three Months Ended March 30, 2018 Pro forma revenue $ 840,487 Pro forma net income $ 10,532 The unaudited pro forma supplemental information is based on estimates and assumptions which the Company believes are reasonable and reflects the pro forma impact of additional amortization related to the fair value of acquired intangible assets, pro forma impact of reflecting acquisition costs, which consisted of legal, advisory and due diligence fees and expenses and the additional pro forma interest expense related to the borrowings under the credit agreement as of the assumed acquisition date. This supplemental pro forma information has been prepared for comparative purposes and does not purport to be indicative of what would have occurred had the acquisition been consummated during the periods for which pro forma information is presented. OGSystems On January 7, 2019, the Company acquired a 100% ownership interest in OGSystems, a privately owned, advanced technology-focused provider of innovative mission solutions for complex defense, intelligence, and security customers, as well as other U.S. federal government customers, for $292.4 million paid in cash. The Company borrowed $110 million under the credit agreement and $150 million on a short-term loan, as described in “Note 12 – Debt and Credit Facilities,” to partially fund the acquisition. In connection with this acquisition, the Company recognized $4.1 million of acquisition-related expenses in “Indirect, general and administrative expense” in the consolidated statements of income for the period ended March 31, 2019, including legal fees, consulting fees, and other miscellaneous direct expenses associated with the acquisition. OGSystems enhances the Company’s artificial intelligence and data analytics expertise with new technologies and solutions. Customers of both companies will benefit from existing, complementary technologies and increased scale, enabling end-to-end solutions under the shared vision of rapid prototyping and agile development. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on preliminary purchase price allocation as of the date of acquisition (in thousands): Amount Cash and cash equivalents $ 5,772 Accounts receivable 9,904 Contract assets 9,747 Prepaid expenses and other current assets 4,307 Property and equipment 4,085 Right of use assets, operating leases 8,826 Goodwill 183,567 Intangible assets 92,300 Other noncurrent assets 10 Accounts payable (5,450 ) Accrued expenses and other current liabilities (7,147 ) Contract liabilities (1,300 ) Short-term lease liabilities, operating leases (805 ) Income tax payable (1,469 ) Deferred tax liabilities (931 ) Long-term lease liabilities, operating leases (8,021 ) Other long-term liabilities (1,015 ) Net assets acquired $ 292,380 Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years): Gross Carrying Amount Amortization Period (in years) Customer relationships $ 57,100 5 Backlog 27,700 3 Trade name 3,800 2 Non compete agreements 2,400 3 Developed technologies $ 1,300 3 The Company is still in the process of finalizing its valuation of developed technology acquired. Amortization expense of $5.9 million related to these intangible assets was recorded for the three months ended March 31, 2019. The entire value of goodwill of $183.6 million was assigned to the Parsons Federal reporting unit and represents synergies expected to be realized from this business combination. Goodwill of $16.0 million is deductible for tax purposes. The amount of revenue generated by OGSystems since the acquisition and included within consolidated revenues for the three months ended March 31, 2019 is $29.0 million. The Company has determined that the presentation of net income from the date of acquisition is impracticable due to the integration of general corporate functions upon acquisition.

Contracts with Customers

Contracts with Customers	3 Months Ended
	Mar. 31, 2019
Revenue From Contract With Customer [Abstract]
Contracts with Customers	5 . Contracts with Customers Disaggregation of Revenue The Company’s contracts contain both fixed-price and cost reimbursable components. Contract types are based on the component that represents the majority of the contract. The following table presents revenue disaggregated by contract type (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Fixed-Price $ 265,408 $ 257,695 Time-and-Materials 227,741 255,706 Cost-Plus 261,530 391,004 Total $ 754,679 $ 904,405 Refer to “Note 20 – Segments Information” for the Company’s revenues by business lines. Contract Assets and Contract Liabilities Contract assets and contract liabilities balances at December 31, 2018 and March 31, 2019 were as follows (in thousands): December 31, 2018 March 31, 2019 $ change % change Contract assets $ 515,319 $ 571,755 $ 56,436 11.0 % Contract liabilities 208,576 225,017 16,441 7.9 % Net contract assets (liabilities) (1) $ 306,743 $ 346,738 $ 39,995 13.0 % (1) During the three months ended March 30, 2018 and March 31, 2019, the Company recognized revenue of approximately $26.3 million and $85.7 million, respectively that was included in the corresponding contract liability balance at December 30, 2017 and December 31, 2018, respectively. The change in contract assets and contract liabilities was the result of normal business activity and not significantly impacted by other factors, except as follows: December 31, 2018 March 31, 2019 Acquired contract assets $ 35,229 $ 9,747 Acquired contract liabilities 3,529 1,300 Reversal of provision for contract losses (1) $ 133,180 $ - (1) Reversal of provision for contract losses of $133.2 million, of which $55.1 million was recorded as an increase in revenue with the remainder recorded as other income. There was no significant impairment of contract assets recognized during the three months ended March 30, 2018 and March 31, 2019. During the three months ended March 30, 2018 and March 31, 2019, the Company recognized revenues of $18.7 Transaction Price Allocated to the Remaining Unsatisfied Performance Obligations The Company’s remaining unsatisfied performance obligations (“RUPO”) as of March 31, 2019 represent a measure of the total dollar value of work to be performed on contracts awarded and in progress. The Company had $5.3 billion in RUPO as of March 31, 2019. RUPO will increase with awards of new contracts and decrease as the Company performs work and recognizes revenue on existing contracts. Projects are included within RUPO at such time the project is awarded and agreement on contract terms has been reached. The difference between RUPO and backlog relates to unexercised option years that are included within backlog and the value of Indefinite Delivery/Indefinite Quantity (“IDIQ”) contracts included in backlog for which delivery orders have not been issued for the Federal Solutions segment. RUPO is comprised of: (a) original transaction price, (b) change orders for which written confirmations from our customers have been received, (c) pending change orders for which the Company expects to receive confirmations in the ordinary course of business, and (d) claim amounts that the Company has made against customers for which it has determined that it has a legal basis under existing contractual arrangements and a significant reversal of revenue is not probable, less revenue recognized to-date. The Company expects to satisfy its RUPO as of March 31, 2019 over the following periods (in thousands): Period RUPO Will Be Satisfied Within One Year Within One to Two Years Thereafter Federal solutions $ 982,972 $ 577,405 $ 324,510 Critical infrastructure 1,560,074 783,585 1,098,715 Total $ 2,543,046 $ 1,360,990 $ 1,423,225

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	6 . In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842)”, which is a new standard related to leases to increase transparency and comparability among organizations by requiring the recognition of right-of-use (“ROU”) assets obtained in exchange for lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company elected to adopt the standard, and available practical expedients, effective January 1, 2019. These practical expedients allowed the Company to keep the lease classification assessed under the previous lease accounting standard (ASC 840) without reassessment under the new standard, and allowed all separate lease components, including non-lease components, to be accounted for as a single lease component for all existing leases prior to adoption of the new standard. Furthermore, the Company made an accounting policy election to not recognize a lease liability and ROU asset for leases with lease terms of twelve months or less. The Company adopted this new standard under the modified retrospective transition approach without adjusting comparative periods in the financial statements, as allowed under Topic 842, and implemented internal controls and key system functionality to enable the preparation of financial information on adoption. The standard had a material impact on the Company’s consolidated balance sheets but did not have an impact on the consolidated income statements. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while accounting for finance leases remained substantially unchanged. As a result of the adoption, the Company recorded a cumulative-effect adjustment to retained earnings of $52.6 million net of deferred tax asset adjustment of $0.7 million, representing the unamortized portion of a deferred gain previously recorded as a sale-leaseback transaction associated with the sale of an office building in 2011. The Company concluded the transaction resulted in the transfer of control of the office building to the buyer-lessor at market terms and would have qualified as a sale under Topic 842 with gain recognition in the period the sale was recognized. The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease ROU assets and current and long-term operating lease liabilities in the consolidated balance sheets. Finance leases are included in other noncurrent assets, accrued expenses and other current liabilities and other long-term liabilities in the consolidated balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, incremental borrowing rates are used based on the information available at commencement date in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. We have lease agreements with lease and non-lease components, which are generally accounted for separately. For certain equipment leases, such as vehicles, we account for the lease and non-lease components as a single lease component. Additionally, for certain equipment leases, we apply a portfolio approach to effectively account for the operating lease ROU assets and liabilities. The Company has operating and finance leases for corporate and project office spaces, vehicles, heavy machinery and office equipment. Our leases have remaining lease terms of one year to 11 years, some of which may include options to extend the leases for up to five years, and some of which may include options to terminate the leases up to the seventh year. As of March 31, 2019, assets recorded under finance leases were $1.3 million The components of lease costs for the three months ended March 31, 2019 are as follows (in thousands): Three Months Ended March 31, 2019 Operating lease cost $ 18,285 Short-term lease cost 2,004 Amortization of right-of-use assets 225 Interest on lease liabilities 16 Sublease income (930 ) Total lease cost $ 19,600 Supplemental cash flow information related to leases for the three months ended March 31, 2019 is as follows (in thousands): Three Months Ended March 31, 2019 Operating cash flows for operating leases $ 18,333 Operating cash flows for financing activities 16 Financing cash flows for finance leases 246 Right-of-use assets operating leases 249,848 Right-of-use assets financing leases $ 1,341 Supplemental balance sheet and other information related to leases as of March 31, 2019 is as follows (in thousands): Three Months Ended March 31, 2019 Operating Leases: Right-of-use assets $ 216,484 Lease liabilities: Current $ 53,029 Long-term 181,274 Total operating lease liabilities $ 234,303 Finance Leases: Other noncurrent assets $ 1,341 Accrued expenses and other current liabilities $ 521 Other long-term liabilities $ 798 Weighted Average Remaining Lease Term: Operating leases 6 years Finance leases 3 years Weighted Average Discount Rate: Operating leases 4.5 % Finance leases 4.5 % As of March 31, 2019, the Company has additional operating leases, primarily for office spaces, that have not yet commenced of $6.2 million. These operating leases will commence in 2019 with lease terms of 4 years to 6 years. A maturity analysis of the future undiscounted cash flows associated with the Company’s operating and finance lease liabilities as of March 31, 2019 is as follows (in thousands): Operating Leases Finance Leases 2019 $ 47,084 $ 427 2020 51,139 510 2021 44,062 353 2022 37,987 113 2023 30,997 - Thereafter 53,870 - Total lease payments 265,139 1,403 Less: imputed interest (30,836 ) (84 ) Total present value of lease liabilities $ 234,303 $ 1,319 As of December 31, 2018, $276.7 million of minimum rental commitments on operating leases was payable as follows: $67.9 million in 2019, $51.0 million in 2020, $42.5 million in 2021, $35.9 million in 2022, $29.4 million in 2023, and $50.0 million thereafter. Rental expense for the three months ended March 30, 2018 was $18.2 million.

Accounts Receivable, Net

Accounts Receivable, Net	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Accounts Receivable, Net	7 . Accounts Receivable, Net Accounts receivable, net consisted of the following as of December 31, 2018 and March 31, 2019 (in thousands): December 31, 2018 March 31, 2019 Billed $ 538,808 $ 534,288 Unbilled 135,180 164,034 Total accounts receivable, gross 673,988 698,322 Allowance for doubtful accounts (50,702 ) (46,398 ) Total accounts receivable, net $ 623,286 $ 651,924 Billed accounts receivable represent amounts billed to clients that have not been collected. Unbilled accounts receivable represent revenue recognized but not yet billed pursuant to contract terms or billed after the period-end date. Substantially all unbilled receivables as of March 31, 2019 are expected to be billed and collected within 12 months. Unbilled accounts receivable at December 31, 2018 and March 31, 2019 include approximately $47.1 million and $49.4 million, respectively, related to unapproved change orders, claims, and requests for equitable adjustment. The Company regularly evaluates these amounts and records adjustments to operating income when recoverability is deemed to have changed. For the periods ended December 31, 2018 and March 31, 2019, no material losses were recognized related to the collectability of claims, unapproved change orders, and requests for equitable adjustment. The allowance for doubtful accounts was determined based on consideration of trends in actual and forecasted credit quality of clients, including delinquency and payment history, type of client, such as a government agency or commercial sector client, and general economic conditions and particular industry conditions that may affect a client’s ability to pay.

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	8 . The following table summarizes the changes in the carrying value of goodwill by reporting segment at December 31, 2018 and March 31, 2019 (in thousands): December 31, 2018 Acquisitions Foreign Exchange March 31, 2019 Federal Solutions $ 666,841 $ 183,500 $ - $ 850,341 Critical Infrastructure 70,097 - 659 70,756 Total $ 736,938 $ 183,500 $ 659 $ 921,097

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets	9 . The gross amount and accumulated amortization of intangible assets with finite useful lives included in “Intangible assets, net” on the consolidated balance sheets were as follows (in thousands except for years): December 31, 2018 March 31, 2019 Weighted Average Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortization Period (in years) Backlog $ 80,754 $ (58,295 ) $ 22,459 $ 108,454 $ (65,636 ) $ 42,818 3 Customer relationships 121,629 (38,974 ) 82,655 178,729 (45,839 ) 132,890 7 Leases 670 (561 ) 109 670 (566 ) 104 5 Developed technology 87,839 (15,174 ) 72,665 89,139 (20,736 ) 68,403 4 Trade name 3,600 (2,100 ) 1,500 7,400 (2,992 ) 4,408 1 Non compete agreements - - - 2,400 (200 ) 2,200 2 Other intangibles 275 (145 ) 130 275 (150 ) 125 10 Total intangible assets $ 294,767 $ (115,249 ) $ 179,518 $ 387,067 $ (136,119 ) $ 250,948 The aggregate amortization expense of intangible assets was $1.8 million and $20.9 million for the three months ended March 30, 2018 and March 31, 2019, respectively. Estimated amortization expense in each of the next five years and beyond is as follows (in thousands): March 31, 2019 2019 (remaining) $ 61,883 2020 72,542 2021 68,401 2022 25,808 2023 15,999 Thereafter 6,315 Total $ 250,948

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2019
Property Plant And Equipment [Abstract]
Property and Equipment, Net	10 . Property and equipment consisted of the following at December 31, 2018 and March 31, 2019 (in thousands): December 31, 2018 March 31, 2019 Useful lives (years) Buildings and leasehold improvements $ 54,348 $ 61,631 1-15 Furniture and equipment 81,705 86,174 3-10 Computer systems and equipment 148,255 152,558 3-10 Construction equipment 12,074 11,832 5-7 Accumulated depreciation (204,533 ) (214,896 ) Property and equipment, net $ 91,849 $ 97,298 Depreciation expense of

Sale-Leasebacks

Sale-Leasebacks	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Sale-Leasebacks	1 1 . During fiscal 2011, the Company consummated two sale-leaseback transactions associated with the sale of two office buildings from which the Company recognized a total gain in the consolidated statements of income (loss) of approximately $106.7 million and a total deferred gain of approximately $107.8 million. The current and long-term portion of the deferred gain had been recorded in “Accrued expenses and other current liabilities” and “Deferred gain resulting from sale-leaseback transactions” on the consolidated balance sheet at December 31, 2018, respectively, and was being recognized ratably over the minimum lease terms to which they relate, as an offset to rental expense in “Indirect, general and administrative expenses” in the consolidated statements of income. Amortization of the deferred gain was $1.8 million and $0 for the three months ended March 30, 2018 and March 31, 2019, respectively. The deferred gain balance of $53.3 million as of December 31, 2018 was recognized as an adjustment to beginning retained earnings net of a deferred tax asset adjustment of $0.7 million during January 2019 in connection with the adoption of the new leasing standard. Refer to “Note 6 – Leases”.

Debt and Credit Facilities

Debt and Credit Facilities	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt and Credit Facilities	1 2 . Debt consisted of the following (in thousands): Long-Term: December 31, 2018 March 31, 2019 Revolving credit facility $ 180,000 $ 260,000 Senior notes 250,000 250,000 Debt issuance costs (836 ) (789 ) Total long-term 429,164 509,211 Short-Term: Term Loan - 150,000 Debt issuance costs - (214 ) Total Short-Term - 149,786 Total Debt $ 429,164 $ 658,997 In November 2017, the Company entered into an amended and restated Credit Agreement. The Company incurred approximately $2.0 million of costs in connection with this amendment. Under the agreement, the Company’s revolving credit facility was increased from $500 million to $550 million and the term of the agreement was extended through November 2022. The borrowings under the Credit Agreement bear interest, at the Company’s option, at either the Base Rate (as defined in the Credit Agreement), plus an applicable margin, or LIBOR plus an applicable margin. The applicable margin for Base Rate loans is a range of 0.125% to 1.00% and the applicable margin for LIBOR loans is a range of 1.125% to 2.00%, both based on the leverage ratio of the Company at the end of each fiscal quarter. The rates at December 31, 2018 and March 31, 2019 were 4.253% and 4.267%, respectively. Borrowings under this Credit Agreement are guaranteed by certain of the Company’s operating subsidiaries. Letters of credit commitments outstanding under this agreement aggregated approximately $49.8 million and $48.8 million at December 31, 2018 and March 31, 2019, respectively, which reduced borrowing limits available to the Company. Interest expense related to the credit agreement was $3.4 million for the three months ended March 31, 2019. There were no amounts outstanding during the three months ended March 30, 2018. On July 1, 2014, the Company finalized a private placement whereby the Company raised an aggregate amount of $250.0 million in debt repayable as follows (in thousands): Tranche Debt Amount Maturity Date Interest Rates Senior Note, Series A $ 50,000 July 15, 2021 4.44 % Senior Note, Series B 100,000 July 15, 2024 4.98 % Senior Note, Series C 60,000 July 15, 2026 5.13 % Senior Note, Series D $ 40,000 July 15, 2029 5.38 % The Company incurred approximately $1.1 million of debt issuance costs in connection with the private placement. On August 10, 2018, the Company finalized an amended and restated intercreditor agreement related to this private placement to more closely align certain covenants and definitions with the terms under the 2017 amended and restated Credit Agreement and incurred approximately $0.5 million of additional issuance costs. These costs are presented as a direct deduction from the debt on the face of the consolidated balance sheets. Interest expense related to the Senior Notes approximated $3.1 million and $3.1 million for the periods ended March 30, 2018 and March 31, 2019, respectively. The amortization of debt issuance costs and interest expense are recorded in “Interest expense” on the consolidated statements of income. The Company made interest payments related to the Senior Notes of approximately $6.2 million and $6.2 million during the periods ended March 30, 2018 and March 31, 2019. Interest payable of approximately $5.7 million and $2.6 million is recorded in “Accrued expenses and other current liabilities” on the consolidated balance sheets at December 31, 2018 and March 31, 2019, respectively, related to the Senior Notes. The Credit Agreement and private placement includes various covenants, including restrictions on indebtedness, liens, acquisitions, investments or dispositions, payment of dividends and maintenance of certain financial ratios and conditions. The Company was in compliance with these covenants at December 31, 2018 and March 31, 2019. The Company also has in place several secondary bank credit lines for issuing letters of credit, principally for foreign contracts, to support performance and completion guarantees. Letters of credit commitments outstanding under these bank lines aggregated approximately $223.0 million and $227.7 million at December 31, 2018 and March 31, 2019, respectively. Using a discounted cash flow technique that incorporates a market interest yield curve with adjustments for duration, optionality, and risk profile, the Company has determined that the fair value (level 2) of its debt approximates the carrying value. Refer to “Note 18 – Fair Value of Financial Instruments” for the definition of level 2 of the fair value hierarchy. In January 2019, the Company borrowed $150.0 million under our Term Loan Agreement to partially finance the OGSystems Acquisition. The Term Loan is comprised of Offshore Rate Loans and Base Rate Loans (each as defined in the Term Loan Agreement), with an initial aggregate principal amount of $150.0 million. The Offshore Rate Loans bear interest at a rate per annum of LIBOR, divided by 1.00 minus the Eurodollar Reserve Percentage, plus 1.25%. The Base Rate Loans bear interest at a rate per annum of the sum of (a) the highest of (1) the administrative agent’s reference rate; (2) the rate equal to 1.50% per annum above the Offshore Rate; and (3) the rate equal to 0.50% per annum above the latest federal funds rate, plus (b) 0.25%. On May 10, 2019, the Company used proceeds from its May 8, 2019, initial public offering to repay the $150.0 million outstanding balance under the Term Loan. Upon payment of the outstanding balance the loan was closed. Interest expense related to the term loan was $1.4 million for the three months ended March 31, 2019. There were no amounts outstanding during the three months ended March 30, 2018. Amortization of debt issuance costs for all the Company’s debt and credit facilities was approximately $0.1 million and $0.2 million for the three months ended March 30, 2018 and March 31, 2019, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	1 3 . Historically, the Company has elected to be taxed under the provisions of Subchapter ”S” of the Internal Revenue Code for federal tax purposes. As a result, income has not been subject to U.S. federal income taxes or state income taxes in those states where the ”S” Corporation status is recognized. No provision or liability for federal or state income tax has been provided in the consolidated financial statements except for those states where the ”S” Corporation status is not recognized and for the 1.5% California franchise tax to which the Company is also subject as a California “S” Corporation. The provision for income tax in the historical periods prior to the Company’s initial public offering consists of these taxes and certain foreign taxes where the Company is subject to tax. In connection with the initial public offering on May 8, 2019, the Company’s “S” Corporation status terminated and the Company will be treated as a “C” Corporation under Subchapter C of the Internal Revenue Code. The revocation of the Company’s “S” Corporation election will have a material impact on the Company’s results of operations, financial condition and cash flows. The Company’s effective income tax rate will increase and net income will decrease since the Company will be subject to both federal and state taxes on our earnings. The termination of the “S” Corporation status will be treated as a change in tax status under ASC 740, “Income Taxes”. These rules require that the deferred tax effects of a change in tax status be recorded to income from continuing operations on the date the “S” Corporation status terminates. The Company estimates the effects of the change in tax status based upon forecasted temporary differences for the year to be approximately $55 million to $61 million. This range is subject to revision based upon actual results. As a Subchapter “S” corporation the effective tax rates for the quarters ended March 30, 2018 and March 31, 2019 were 15.54% and 12.35%, respectively. The decrease in the effective rate is principally the result of a change in the jurisdictional earnings. The US government enacted comprehensive tax legislation on December 22, 2017, which is commonly referred to as the Tax Cuts and Jobs Act ("TCJA"). The TCJA significantly revised the U.S. corporate income tax regime by, among other things, lowering the U.S. corporate tax rate from 35% to 21% effective January 1, 2018. The TCJA also repealed the deduction for domestic production activities, limited the deductibility of certain executive compensation, and implemented a modified territorial tax system with the introduction of the Global Intangible Low-Taxed Income (“GILTI”) tax rules. The TCJA also imposes a one-time transition tax on deemed repatriation of historical earnings of foreign subsidiaries. As a Subchapter “S” corporation, the TCJA has had limited effect on our effective tax rate. However, after the Company revokes the “S” Corporation election, the Company expects to be subject to the federal and state rates, the GILTI tax rules and other changes in the rules under the TCJA. Because of the complexity of the new GILTI tax rules, and the expected change in status, the Company will continue to evaluate the impact of this provision and the application of ASC 740, Income Taxes. Under GAAP, the Company is allowed to make an accounting policy election of either (i) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the "period cost method"), or (ii) factoring such amounts into a Company's measurement of its deferred taxes (the "deferred method"). The Company has elected the period cost method. As of March 31, 2019, the Company’s deferred tax assets included a valuation allowance of $ 6.7 million primarily related to foreign net operating loss carryforwards that the Company determined were not more likely than not to be realized. The factors used to assess the likelihood of realization were the past performance of the related entities, our forecast of future taxable income, and available tax planning strategies that could be implemented to realize the deferred tax assets. The ability or failure to achieve the forecasted taxable income in these entities could affect the ultimate realization of deferred tax assets. As of December 31, 2018 and March 31, 2019, the liability for income taxes associated with uncertain tax positions was $9.9 million and $10.7 million, respectively. In the normal course of business, the Company is subject to tax audit by several jurisdictions and believes the outcomes which are reasonably possible within the next twelve months, including lapses in statutes of limitations, could result in adjustments, but will not result in a material change in the liability for uncertain tax positions.

Commitment and Contingencies

Commitment and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 4 . We are subject to certain lawsuits, claims and assessments that arise in the ordinary course of business. Additionally, the Company has been named as a defendant in lawsuits alleging personal injuries as a result of contact with asbestos products at various project sites. We believe that any significant costs relating to these claims will be reimbursed by applicable insurance and, although there can be no assurance that these matters will be resolved favorably, management believes that the ultimate resolution of any of these claims will not have a material adverse effect on our consolidated financial position, results of operations, or cash flows. We record a liability when we believe that it is both probable that a loss has been incurred and the amount of loss or range of loss can be reasonably estimated. When using a range of loss estimate, the Company records the liability using the low end of the range. The Company records a corresponding receivable for costs covered under its insurance policies. Management judgment is required to determine the outcome and the estimated amount of a loss related to such matters. Management believes that there are no claims or assessments outstanding which would materially affect our consolidated results of operations or our financial position. On or about March 1, 2017, the Peninsula Corridor Joint Powers Board, or the JPB, filed a lawsuit against Parsons Transportation Group, Inc., or PTG, in the Superior Court of California, County of San Mateo, in connection with a positive train control project on which PTG was engaged prior to termination of its contract by the JPB. PTG had previously filed a lawsuit against the JPB for breach of contract and wrongful termination. The JPB seeks damages in excess of $100.0 million, which the Company is currently disputing. In addition to filing a complaint for breach of contract and wrongful termination, the Company has denied the allegations raised by the JPB and, accordingly, filed affirmative defenses. The Company is currently defending against the JPB’s claims and the parties are still engaged in discovery. The Company also has a professional liability insurance policy to the extent the JPB proves any errors or omissions occurred. At this time, it is too soon to determine the outcome of the litigation or assess the potential range of loss, if any. The Company has also filed a third party claim against a subcontractor for indemnification in connection with this matter. In September 2015, a former Parsons employee filed an action in the United States District Court for the Northern District of Alabama against us as a qui tam relator on behalf of the United States (the “Relator”) alleging violation of the False Claims Act. The United States government did not intervene in this matter as it is allowed to do so under the statute. The Company filed a motion to dismiss the lawsuit on the grounds that the Relator did not meet the applicable statute of limitations. The District Court granted the motion to dismiss. The Relator’s attorney appealed the decision to the United States Court of Appeals of the Eleventh Circuit, which ultimately ruled in favor of the Relator, and the Company petitioned the United States Supreme Court to review the decision. The Supreme Court reviewed the decision and accepted the position of the relator. The case was thus remanded to the United States District Court for the Northern District of Alabama. The defendants, including Parsons, will file appropriate pleadings opposing the allegations. At this time, it is too soon to determine the outcome of the litigation or assess the potential range of loss, if any. Federal government contracts are subject to audits, which are performed for the most part by the Defense Contract Audit Agency (“DCAA”). Audits by the DCAA and other agencies consist of reviews of our overhead rates, operating systems and cost proposals to ensure that we account for such costs in accordance with the Cost Accounting Standards (“CAS”). If the DCAA determines we have not accounted for such costs in accordance with the CAS, the DCAA may disallow these costs. The disallowance of such costs may result in a reduction of revenue and additional liability for the Company. Historically, the Company has not experienced any material disallowed costs as a result of government audits. However, the Company can provide no assurance that the DCAA or other government audits will not result in material disallowances for incurred costs in the future. All audits of costs incurred on work performed through 2009 have been closed, and years thereafter remain open. Although there can be no assurance that these matters will be resolved favorably, management believes that their ultimate resolution will not have a material adverse impact on the Company’s consolidated financial position, results of operations, or cash flows. The Company accrues a liability when management believes it is both probable that a liability has been incurred and the amount of loss or range of loss can be reasonably estimated. The Company records a corresponding receivable for costs covered under the insurance policies.

Retirement and Other Benefit Pl

Retirement and Other Benefit Plans	3 Months Ended
	Mar. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Retirement and Other Benefit Plans	1 5 . The Company’s principal retirement benefit plan is the ESOP, a stock bonus plan, established in 1975 to cover eligible employees of the Company and certain affiliated companies. Contributions of treasury stock to the ESOP are made annually in amounts determined by the Company’s board of directors and are held in trust for the sole benefit of the participants. Shares allocated to a participant’s account are fully vested after six years of credited service, or in the event(s) of reaching age 65, death or disability while an active employee of the Company. All of the Company’s common stock was acquired by the ESOP in conjunction with a reorganization in 1984, which was financed by the Company. Upon retirement, death, termination due to permanent disability, a severe financial hardship, or the exercise of diversification rights, participants’ interests in their ESOP accounts are redeemable at the current price per share of the stock. Such per share prices are established by the ESOP trustee, taking into account, among other things, the advice of a third-party valuation consultant for the ESOP trustee, as well as the ESOP trustee’s knowledge of the Company, as of the end of the plan year preceding distribution. Under the terms of the ESOP plan, when participants hold shares that are not readily tradeable, the Company is obligated to redeem eligible participants’ interests in their ESOP accounts for cash upon an employee’s election. All shares held by the ESOP are eventually redeemable in the future for cash at the option of the holder once vesting and eligibility requirements have been met. The Company presents all shares held by the ESOP as temporary equity on the consolidated balance sheets at their redemption value. Total ESOP contribution expense was approximately $11.2 million and $12.2 million for the three months ended March 30, 2018 and March 31, 2019, respectively, and is recorded in “Direct costs of contracts” and “Indirect, general and administrative expense” in the consolidated statements of income. The fiscal 2019 ESOP contribution has not yet been made. The amount is currently included in accrued liabilities. At December 31, 2018 and March 31, 2019, 78,172,809 shares and 78,138,831 shares of the Company’s stock were held by the ESOP which the Company recorded at their aggregate redemption value of $1.9 billion. During the year ended December 31, 2018 and the three months ended March 31, 2019, the Company did not declare any dividends. The Company also maintains a defined contribution plan (the “401(k) Plan”). Substantially all domestic employees are entitled to participate in the 401(k) Plan, subject to certain minimum requirements. The Company’s contribution to the 401(k) Plan for the three months ended March 30, 2018 and March 31, 2019 amounted to $4.7 million and $9.2 million, respectively. As part of an acquisition in 2014, the Company acquired a defined contribution pension plan, a defined benefit pension plan, and supplemental retirement plan. For the defined contribution pension plan, the Company contributes a base amount plus an additional amount based upon a predetermined formula. At December 31, 2018 and March 31, 2019, the defined benefit pension plan was in a net asset position of $1.7 million and $1.7 million, respectively, which is recorded in “Other noncurrent assets” on the consolidated balance sheets.

Investments in and Advances to

Investments in and Advances to Joint Ventures	3 Months Ended
	Mar. 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Investments in and Advances to Joint Ventures	1 6 . The Company participates in joint ventures to bid, negotiate and complete specific projects. The Company is required to consolidate these joint ventures if it holds the majority voting interest or if the Company meets the criteria under the consolidation model, as described below. The Company performs an analysis to determine whether its variable interests give the Company a controlling financial interest in a Variable Interest Entity (“VIE”) for which the Company is the primary beneficiary and should, therefore, be consolidated. Such analysis requires the Company to assess whether it has the power to direct the activities of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company analyzed all of its joint ventures and classified them into two groups: (1) joint ventures that must be consolidated because they are either not VIEs and the Company holds the majority voting interest, or because they are VIEs and the Company is the primary beneficiary; and (2) joint ventures that do not need to be consolidated because they are either not VIEs and the Company holds a minority voting interest, or because they are VIEs and the Company is not the primary beneficiary. Many of the Company’s joint venture agreements provide for capital calls to fund operations, as necessary; however, such funding is infrequent and is not anticipated to be material. Letters of credit outstanding described in “Note 12 – Debt and Credit Facilities” that relate to project ventures are approximately $76.8 million and $77.2 million at December 31, 2018 and March 31, 2019, respectively. In the table below, aggregated financial information relating to the Company’s joint ventures is provided because their nature, risk and reward characteristics are similar. None of the Company’s current joint ventures that meet the characteristics of a VIE are individually significant to the consolidated financial statements. Consolidated Joint Ventures The following represents financial information for consolidated joint ventures included in the consolidated financial statements (in thousands): December 31, 2018 March 31, 2019 Current assets $ 287,227 $ 269,856 Noncurrent assets 2,689 2,285 Total assets 289,916 272,141 Current liabilities 199,833 209,909 Total liabilities 199,833 209,909 Total joint venture equity $ 90,083 $ 62,232 Three Months Ended March 30, 2018 March 31, 2019 Revenue $ 112,121 $ 115,104 Costs 106,166 107,206 Net income 5,955 7,898 Net income attributable to noncontrolling interests $ 3,815 $ 3,645 The assets of the consolidated joint ventures are restricted for use only by the particular joint venture and are not available for the Company’s general operations. Unconsolidated Joint Ventures The Company accounts for its unconsolidated joint ventures using the equity method of accounting. Under this method, the Company recognizes its proportionate share of the net earnings of these joint ventures as “Equity in earnings (loss) of unconsolidated joint ventures” in the consolidated statements of income. The Company’s maximum exposure to loss as a result of its investments in unconsolidated VIEs is typically limited to the aggregate of the carrying value of the investment and future funding commitments. The following represents the financial information of the Company’s unconsolidated joint ventures as presented in their unaudited financial statements (in thousands): December 31, 2018 March 31, 2019 Current assets $ 707,457 $ 675,030 Noncurrent assets 876,385 894,191 Total assets 1,583,842 1,569,221 Current liabilities 560,306 487,933 Noncurrent liabilities 813,269 848,105 Total liabilities 1,373,575 1,336,038 Total joint venture equity 210,267 233,183 Investments in and advances to unconsolidated joint ventures $ 63,560 $ 67,202 Three Months Ended March 30, 2018 March 31, 2019 Revenue $ 281,078 $ 229,466 Costs 253,664 216,780 Net income 27,414 12,686 Equity in earnings of unconsolidated joint ventures $ 11,031 $ 10,397 The Company received net distributions from its unconsolidated joint ventures of $12.3 million and $8.1 million for the three months ended March 30, 2018 and March 31, 2019, respectively.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	1 7 . The Company often provides services to unconsolidated joint ventures and revenues include amounts related to recovering overhead costs for these services. For the three months ended March 30, 2018 and March 31, 2019, revenues included $33.7 million and $33.6 million, respectively, related to services the Company provided to unconsolidated joint ventures. For the three months ended March 30, 2018 and March 31, 2019, the Company incurred approximately $25.9 million and $27.2 million, respectively, of reimbursable costs. Amounts included in the consolidated balance sheets related to services the Company provided to unconsolidated joint ventures is as follows (in thousands): December 31, 2018 March 31, 2019 Accounts receivable $ 38,742 $ 30,263 Contract assets 2,648 3,527 Contract liabilities $ 10,861 $ 9,603

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	1 8 . The authoritative guidance on fair value measurement defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (referred to as an “exit price”). At December 31, 2018 and March 31, 2019, the Company’s financial instruments include cash, cash equivalents, accounts receivable, accounts payable, and other liabilities. The fair values of these financial instruments approximate their carrying values due to their short-term maturities. Investments measured at fair value are based on one or more of the following three valuation techniques: • Market approach —Prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities; • Cost approach —Amount that would be required to replace the service capacity of an asset (i.e., replacement cost); and • Income approach —Techniques to convert future amounts to a single present amount based on market expectations (including present value techniques, option-pricing models and lattice models). In addition, the guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets and liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are: Level 1 Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets and liabilities; Level 2 Pricing inputs that include quoted prices for similar assets and liabilities in active markets and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the instrument; and Level 3 Prices or valuations that require inputs that are both significant to the fair value measurements and unobservable. The methods described above may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. The following table sets forth assets associated with the pension plan in “Note 15 – Retirement and Other Benefit Plans” that are accounted for at fair value by Level within the fair value hierarchy. Fair value as of December 31, 2018 (in thousands): December 31, 2108 Level 1 Level 2 Level 3 Total Mutual funds $ 2,539 $ - $ - $ 2,539 Fixed income - 10,168 - 10,168 Cash and cash equivalents 361 - - 361 $ 2,900 $ 10,168 $ - $ 13,068 Fair value as of March 31, 2019 (in thousands): March 31, 2109 Level 1 Level 2 Level 3 Total Mutual funds $ 2,715 $ - $ - $ 2,715 Fixed income - 10,689 - 10,689 Cash and cash equivalents 264 - - 264 $ 2,979 $ 10,689 $ - $ 13,667 As described in “Note 15 – Retirement and Other Benefit Plans,” the Company acquired a defined contribution pension plan, a defined benefit pension plan, and supplemental retirement plans. At December 31, 2018 and March 31, 2019, the Company measured the mutual funds held within the defined benefit pension plan at fair value using unadjusted quoted prices in active markets that are accessible for identical assets. The Company measured the fixed income securities using market bid and ask prices. The inputs that are significant to valuation of fixed income securities are generally observable and therefore have been classified as Level 2. The following table sets forth redeemable common stock associated with the ESOP in as described in “Note 14 – Retirement and Other Benefit Plans” that is accounted for at fair value by Level within the fair value hierarchy. Fair value as of December 31, 2018 (in thousands): December 31, 2108 Level 1 Level 2 Level 3 Total Redeemable common stock $ - $ - $ 1,876,309 $ 1,876,309 Fair value as of March 31, 2019 (in thousands): March 31, 2109 Level 1 Level 2 Level 3 Total Redeemable common stock $ - $ - $ 1,875,332 $ 1,875,332 As described in “Note 15 – Retirement and Other Benefit Plans,” the Company is obligated to redeem eligible participants’ interests in their ESOP accounts for cash upon an employee’s election. All shares held by the ESOP are eventually redeemable in the future for cash at the option of the holder once vesting and eligibility requirements have been met. The Company presents all shares held by the ESOP as temporary equity on the consolidated balance sheets at their redemption value. At December 31, 2018 and March 31, 2019, approximately 78,172,809 shares and 78,138,831 shares, respectively of the Company’s stock were held by the ESOP which the Company recorded at their aggregate redemption values of $1.9 billion. The following tables present a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3) (in thousands): Balance at December 31, 2018 $ 1,876,309 Purchases of treasury stock (813 ) Share price adjustment (164 ) Balance at March 31, 2019 $ 1,875,332

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	1 9 . Basic earnings per common share is computed using the weighted average number of shares outstanding during the period and income available to shareholders. Diluted earnings per share (“EPS”) is computed similar to basic EPS, except the weighted average number of shares outstanding is increased to include the dilutive effects of outstanding stock options and other stock-based awards. There were no dilutive securities outstanding for the three months ended March 30, 2018 and March 31, 2019. The weighted average number of shares used to compute basic and diluted EPS were (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Basic weighted average number of shares outstanding 81,846,305 78,161,484 Dilutive common share equivalents - - Diluted weighted average number of shares outstanding 81,846,305 78,161,484

Segments Information

Segments Information	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segments Information	20 . The Company operates in two reportable segments: Federal Solutions and Critical Infrastructure. The Federal Solutions segment is a high-end services provider to the U.S. government, delivering timely, cost-effective solutions for mission-critical projects. The segment provides advanced technologies, including cybersecurity, missile defense systems, and subsurface munitions detection, as well as military facility modernization, logistics support, chemical weapon remediation and engineering services. The Critical Infrastructure segment provides integrated design and engineering services for complex physical and digital infrastructure around the globe. The Critical Infrastructure segment is a technology innovator focused on next generation infrastructure. Industry leading capabilities in design and project management allow the Company to deliver significant value to customers by employing cutting-edge technologies, improving timelines and reducing costs. The Company defines its reportable segments based on the way the chief operating decision maker (“CODM”), currently its Chairman and Chief Executive Officer, evaluates the performance of each segment and manages the operations of the Company for purposes of allocating resources among the segments. The CODM evaluates segment operating performance using segment Revenue and segment Adjusted EBITDA attributable to Parsons Corporation. The following table summarizes business segment revenue for the periods presented (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Federal Solutions revenue $ 291,335 $ 422,812 Critical Infrastructure revenue 463,344 481,593 Total revenue $ 754,679 $ 904,405 The Company defines Adjusted EBITDA attributable to Parsons Corporation as Adjusted EBITDA excluding Adjusted EBITDA attributable to noncontrolling interests. The Company defines Adjusted EBITDA as net income (loss) attributable to Parsons Corporation, adjusted to include net income (loss) attributable to noncontrolling interests and to exclude interest expense (net of interest income), provision for income taxes, depreciation and amortization and certain other items that are not considered in the evaluation of ongoing operating performance. These other items include net income (loss) attributable to noncontrolling interests, asset impairment charges, income and expense recognized on litigation matters, expenses incurred in connection with acquisitions and other non-recurring transaction costs and expenses related to our prior restructuring. The following table reconciles business segment Adjusted EBITDA attributable to Parsons Corporation to Net Income attributable to Parsons Corporation for the periods presented (in thousands): Three Months Ended Adjusted EBITDA attributable to Parsons Corporation March 30, 2018 March 31, 2019 Federal Solutions $ 20,154 $ 38,866 Critical Infrastructure 23,656 25,559 Adjusted EBITDA attributable to Parsons Corporation 43,810 64,425 Adjusted EBITDA attributable to noncontrolling interests 3,920 3,749 Depreciation and amortization (9,009 ) (30,591 ) Interest expense, net (3,258 ) (7,815 ) Income tax expense (5,353 ) (1,886 ) Litigation-related expenses(a) (2,330 ) - Amortization of deferred gain resulting from sale-leaseback transactions(b) 1,813 - Transaction-related costs(c) (125 ) (9,355 ) Restructuring(d) - (2,218 ) HCM software implementation costs(e) - (2,912 ) Other(f) (366 ) (11 ) Net income including noncontrolling interests 29,102 13,386 Net income attributable to noncontrolling interests 3,815 3,645 Net income attributable to Parsons Corporation $ 25,287 $ 9,741 (a) Reflects interest expense in “(Interest and other expenses) gain associated with claim on long-term contract” in our results of operations associated with a lawsuit against a joint venture in which the Company is the managing partner. Please see “Note 14 – Commitments and Contingencies” in the Company’s Form S-1/A filed on April 29, 2019, for a description of this matter, which was resolved in favor of the Company on June 13, 2018. (b) Reflects recognized deferred gains related to sales-leaseback transactions described in “Note 11 – Sale-Leasebacks.” (c) Reflects costs incurred in connection with acquisitions, initial public offering, and other non-recurring transaction costs, primarily fees paid for professional services and employee retention. (d) Reflects costs associated with our corporate restructuring initiatives. (e) Reflects implementation costs incurred in connection with a new human resources and payroll application. (f) Includes a loss from sale of a subsidiary and other individually insignificant items that are non-recurring in nature for the quarter ended March 30, 2018, and a combination of gain/loss related to sale of fixed assets and other individually insignificant items that are non-recurring in nature for the quarter ended March 31, 2019. Asset information by segment is not a key measure of performance used by the CODM. The following tables presents revenues and property and equipment, net by geographic area (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Revenue North America $ 587,307 $ 731,030 Middle East 162,406 167,952 Rest of World 4,966 5,423 Total Revenue $ 754,679 $ 904,405 The geographic location of revenue is determined by the location of the customer. Three Months Ended December 31, 2018 March 31, 2019 Property and Equipment, Net North America $ 86,847 $ 92,262 Middle East 5,002 5,036 Total Property and Equipment, Net $ 91,849 $ 97,298 North America revenue includes $540.5 million and $669.2 million of United States revenue for the three months ended March 30, 2018 and March 31, 2019, respectively. North America property and equipment, net includes $79.9 million and $86.2 million of property and equipment, net in the United States at December 31, 2018 and March 31, 2019, respectively. The following table presents revenues by business lines (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Revenue Cyber & Intelligence $ 44,367 $ 76,110 Defense 73,540 134,990 Mission Solutions 74,149 68,090 Engineered Systems 99,279 114,666 Geospatial - 28,956 Federal Solutions revenues 291,335 422,812 Connect Communities 160,913 156,876 Mobility Solutions 255,679 269,114 Industrial 46,752 55,603 Critical Infrastructure revenues 463,344 481,593 Total Revenue $ 754,679 $ 904,405

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	2 1 . On April 3, 2019, the Company’s board of directors declared a cash dividend to the Company’s existing shareholder in the amount of $2.00 per share, or $52.1 million in the aggregate (the “IPO Dividend”). The IPO Dividend was paid on May 10, 2019. On April 15, 2019, the board of directors of the Company declared a common stock dividend in a ratio of two shares of common stock for every one share of common stock presently held by the Company’s stockholder (the “Stock Dividend”). The record date of this common stock dividend, which the Company refers to as the Stock Dividend was May 7, 2019, the day immediately prior to the consummation of the Company’s initial public offering on May 8, 2019, and the payment date of the Stock Dividend was May 8, 2019. Purchasers of the Company’s common stock in the Company’s public offering will not be entitled to receive any portion of the Stock Dividend.

Basis of Presentation and Pri_2

Basis of Presentation and Principles of Consolidation (Policies)	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Fiscal Period	Fiscal Periods In October 2018, our board of directors approved a change in our annual and quarterly fiscal period ends from the last Friday on or before the calendar year or quarterly month-end to the last day of the calendar year or quarterly month-end. Accordingly, the period end for the first quarters of fiscal 2018 and fiscal 2019 are March 30, 2018 and March 31, 2019, respectively. The number of days in the quarters ended March 30, 2018 and March 31, 2019 were 91 and 90, respectively.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual amounts could differ from those estimates. The Company’s most significant estimates and judgments involve revenue recognition with respect to the determination of the costs to complete contracts and transaction price; determination of self-insurance reserves; valuation of the Company’s fair value of common stock; useful lives of property and equipment and intangible assets; calculation of allowance for doubtful accounts; valuation of deferred income tax assets and uncertain tax positions, among others. Please refer to “Note 2 – Summary of Significant Accounting Policies” of Notes to Consolidated Financial Statements included in the Company’s Form S-1/A filed April 29, 2019, for a discussion of the significant estimates and assumptions affecting our consolidated financial statements. Estimates of costs to complete contracts are continually evaluated as work progresses and are revised when necessary. When a change in estimate is determined to have an impact on contract profit, the Company records a positive or negative adjustment to the consolidated statement of income.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2019
Polaris Alpha
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on preliminary purchase price allocation as of the date of acquisition (in thousands): Amount Cash and cash equivalents $ 7,914 Accounts receivable 29,688 Contract assets 35,229 Prepaid expenses and other current assets 9,295 Property and equipment 9,024 Goodwill 243,471 Intangible assets 199,520 Other noncurrent assets 2,203 Accounts payable (13,942 ) Accrued expenses and other current liabilities (26,419 ) Contract liabilities (3,529 ) Deferred tax liabilities (2,231 ) Other long-term liabilities (1,146 ) Net assets acquired $ 489,077
Schedule of Intangible Assets Value on Purchase Price	Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years): Gross Carrying Amount Amortization Period (in years) Developed technology $ 84,900 4 Customer relationships 76,000 8 Backlog 34,900 2 Trade name 3,600 1 Leases $ 120 6
Schedule of Supplemental Pro Forma Information (Unaudited)	Supplemental information on an unaudited pro forma operating results assuming the Polaris Alpha acquisition had been consummated as of the beginning of fiscal year 2018 (December 31, 2017) (in thousands) is as follows: Three Months Ended March 30, 2018 Pro forma revenue $ 840,487 Pro forma net income $ 10,532
OGSystems
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed based on preliminary purchase price allocation as of the date of acquisition (in thousands): Amount Cash and cash equivalents $ 5,772 Accounts receivable 9,904 Contract assets 9,747 Prepaid expenses and other current assets 4,307 Property and equipment 4,085 Right of use assets, operating leases 8,826 Goodwill 183,567 Intangible assets 92,300 Other noncurrent assets 10 Accounts payable (5,450 ) Accrued expenses and other current liabilities (7,147 ) Contract liabilities (1,300 ) Short-term lease liabilities, operating leases (805 ) Income tax payable (1,469 ) Deferred tax liabilities (931 ) Long-term lease liabilities, operating leases (8,021 ) Other long-term liabilities (1,015 ) Net assets acquired $ 292,380
Schedule of Intangible Assets Value on Purchase Price	Of the total purchase price, the following values were assigned to intangible assets (in thousands, except for years): Gross Carrying Amount Amortization Period (in years) Customer relationships $ 57,100 5 Backlog 27,700 3 Trade name 3,800 2 Non compete agreements 2,400 3 Developed technologies $ 1,300 3

Contracts with Customers (Table

Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue From Contract With Customer [Abstract]
Summary of Disaggregation of Revenue	The Company’s contracts contain both fixed-price and cost reimbursable components. Contract types are based on the component that represents the majority of the contract. The following table presents revenue disaggregated by contract type (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Fixed-Price $ 265,408 $ 257,695 Time-and-Materials 227,741 255,706 Cost-Plus 261,530 391,004 Total $ 754,679 $ 904,405
Summary of Contract Assets and Contract Liabilities	Contract assets and contract liabilities balances at December 31, 2018 and March 31, 2019 were as follows (in thousands): December 31, 2018 March 31, 2019 $ change % change Contract assets $ 515,319 $ 571,755 $ 56,436 11.0 % Contract liabilities 208,576 225,017 16,441 7.9 % Net contract assets (liabilities) (1) $ 306,743 $ 346,738 $ 39,995 13.0 % (1)
Summary of Change in Contract Assets and Contract Liabilities	The change in contract assets and contract liabilities was the result of normal business activity and not significantly impacted by other factors, except as follows: December 31, 2018 March 31, 2019 Acquired contract assets $ 35,229 $ 9,747 Acquired contract liabilities 3,529 1,300 Reversal of provision for contract losses (1) $ 133,180 $ - (1) Reversal of provision for contract losses of $133.2 million, of which $55.1 million was recorded as an increase in revenue with the remainder recorded as other income.
Summary of Remaining Unsatisfied Performance Obligations Expect to Satisfy	The Company expects to satisfy its RUPO as of March 31, 2019 over the following periods (in thousands): Period RUPO Will Be Satisfied Within One Year Within One to Two Years Thereafter Federal solutions $ 982,972 $ 577,405 $ 324,510 Critical infrastructure 1,560,074 783,585 1,098,715 Total $ 2,543,046 $ 1,360,990 $ 1,423,225

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Summary of Lease Costs	The components of lease costs for the three months ended March 31, 2019 are as follows (in thousands): Three Months Ended March 31, 2019 Operating lease cost $ 18,285 Short-term lease cost 2,004 Amortization of right-of-use assets 225 Interest on lease liabilities 16 Sublease income (930 ) Total lease cost $ 19,600
Schedule of Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases for the three months ended March 31, 2019 is as follows (in thousands): Three Months Ended March 31, 2019 Operating cash flows for operating leases $ 18,333 Operating cash flows for financing activities 16 Financing cash flows for finance leases 246 Right-of-use assets operating leases 249,848 Right-of-use assets financing leases $ 1,341
Schedule of Supplemental Balance Sheet and Other Information Related to Leases	Supplemental balance sheet and other information related to leases as of March 31, 2019 is as follows (in thousands): Three Months Ended March 31, 2019 Operating Leases: Right-of-use assets $ 216,484 Lease liabilities: Current $ 53,029 Long-term 181,274 Total operating lease liabilities $ 234,303 Finance Leases: Other noncurrent assets $ 1,341 Accrued expenses and other current liabilities $ 521 Other long-term liabilities $ 798 Weighted Average Remaining Lease Term: Operating leases 6 years Finance leases 3 years Weighted Average Discount Rate: Operating leases 4.5 % Finance leases 4.5 %
Schedule of Maturity Analysis of Future Undiscounted Cash Flows	A maturity analysis of the future undiscounted cash flows associated with the Company’s operating and finance lease liabilities as of March 31, 2019 is as follows (in thousands): Operating Leases Finance Leases 2019 $ 47,084 $ 427 2020 51,139 510 2021 44,062 353 2022 37,987 113 2023 30,997 - Thereafter 53,870 - Total lease payments 265,139 1,403 Less: imputed interest (30,836 ) (84 ) Total present value of lease liabilities $ 234,303 $ 1,319

Accounts Receivable, Net (Table

Accounts Receivable, Net (Tables)	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Summary of Accounts Receivable, Net	Accounts receivable, net consisted of the following as of December 31, 2018 and March 31, 2019 (in thousands): December 31, 2018 March 31, 2019 Billed $ 538,808 $ 534,288 Unbilled 135,180 164,034 Total accounts receivable, gross 673,988 698,322 Allowance for doubtful accounts (50,702 ) (46,398 ) Total accounts receivable, net $ 623,286 $ 651,924

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Changes in Carrying Value of Goodwill by Reporting Segment	The following table summarizes the changes in the carrying value of goodwill by reporting segment at December 31, 2018 and March 31, 2019 (in thousands): December 31, 2018 Acquisitions Foreign Exchange March 31, 2019 Federal Solutions $ 666,841 $ 183,500 $ - $ 850,341 Critical Infrastructure 70,097 - 659 70,756 Total $ 736,938 $ 183,500 $ 659 $ 921,097

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Gross Amount and Accumulated Amortization of Intangible Assets	The gross amount and accumulated amortization of intangible assets with finite useful lives included in “Intangible assets, net” on the consolidated balance sheets were as follows (in thousands except for years): December 31, 2018 March 31, 2019 Weighted Average Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortization Period (in years) Backlog $ 80,754 $ (58,295 ) $ 22,459 $ 108,454 $ (65,636 ) $ 42,818 3 Customer relationships 121,629 (38,974 ) 82,655 178,729 (45,839 ) 132,890 7 Leases 670 (561 ) 109 670 (566 ) 104 5 Developed technology 87,839 (15,174 ) 72,665 89,139 (20,736 ) 68,403 4 Trade name 3,600 (2,100 ) 1,500 7,400 (2,992 ) 4,408 1 Non compete agreements - - - 2,400 (200 ) 2,200 2 Other intangibles 275 (145 ) 130 275 (150 ) 125 10 Total intangible assets $ 294,767 $ (115,249 ) $ 179,518 $ 387,067 $ (136,119 ) $ 250,948
Schedule of Estimated Amortization Expense	Estimated amortization expense in each of the next five years and beyond is as follows (in thousands): March 31, 2019 2019 (remaining) $ 61,883 2020 72,542 2021 68,401 2022 25,808 2023 15,999 Thereafter 6,315 Total $ 250,948

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2019
Property Plant And Equipment [Abstract]
Schedule of Property and equipment, net	Property and equipment consisted of the following at December 31, 2018 and March 31, 2019 (in thousands): December 31, 2018 March 31, 2019 Useful lives (years) Buildings and leasehold improvements $ 54,348 $ 61,631 1-15 Furniture and equipment 81,705 86,174 3-10 Computer systems and equipment 148,255 152,558 3-10 Construction equipment 12,074 11,832 5-7 Accumulated depreciation (204,533 ) (214,896 ) Property and equipment, net $ 91,849 $ 97,298

Debt and Credit Facilities (Tab

Debt and Credit Facilities (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long Term Debt	Debt consisted of the following (in thousands): Long-Term: December 31, 2018 March 31, 2019 Revolving credit facility $ 180,000 $ 260,000 Senior notes 250,000 250,000 Debt issuance costs (836 ) (789 ) Total long-term 429,164 509,211 Short-Term: Term Loan - 150,000 Debt issuance costs - (214 ) Total Short-Term - 149,786 Total Debt $ 429,164 $ 658,997
Schedule of Aggregate Amount Debt Repayable	On July 1, 2014, the Company finalized a private placement whereby the Company raised an aggregate amount of $250.0 million in debt repayable as follows (in thousands): Tranche Debt Amount Maturity Date Interest Rates Senior Note, Series A $ 50,000 July 15, 2021 4.44 % Senior Note, Series B 100,000 July 15, 2024 4.98 % Senior Note, Series C 60,000 July 15, 2026 5.13 % Senior Note, Series D $ 40,000 July 15, 2029 5.38 %

Investments in and Advances t_2

Investments in and Advances to Joint Ventures (Tables)	3 Months Ended
	Mar. 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Summary of Financial Information for Consolidated Joint Ventures	The following represents financial information for consolidated joint ventures included in the consolidated financial statements (in thousands): December 31, 2018 March 31, 2019 Current assets $ 287,227 $ 269,856 Noncurrent assets 2,689 2,285 Total assets 289,916 272,141 Current liabilities 199,833 209,909 Total liabilities 199,833 209,909 Total joint venture equity $ 90,083 $ 62,232 Three Months Ended March 30, 2018 March 31, 2019 Revenue $ 112,121 $ 115,104 Costs 106,166 107,206 Net income 5,955 7,898 Net income attributable to noncontrolling interests $ 3,815 $ 3,645
Summary of Financial Information for Unconsolidated Joint Ventures	The following represents the financial information of the Company’s unconsolidated joint ventures as presented in their unaudited financial statements (in thousands): December 31, 2018 March 31, 2019 Current assets $ 707,457 $ 675,030 Noncurrent assets 876,385 894,191 Total assets 1,583,842 1,569,221 Current liabilities 560,306 487,933 Noncurrent liabilities 813,269 848,105 Total liabilities 1,373,575 1,336,038 Total joint venture equity 210,267 233,183 Investments in and advances to unconsolidated joint ventures $ 63,560 $ 67,202 Three Months Ended March 30, 2018 March 31, 2019 Revenue $ 281,078 $ 229,466 Costs 253,664 216,780 Net income 27,414 12,686 Equity in earnings of unconsolidated joint ventures $ 11,031 $ 10,397

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Schedule of Consolidated Balance Sheet Related to Services Provided to Unconsolidated Joint Ventures	Amounts included in the consolidated balance sheets related to services the Company provided to unconsolidated joint ventures is as follows (in thousands): December 31, 2018 March 31, 2019 Accounts receivable $ 38,742 $ 30,263 Contract assets 2,648 3,527 Contract liabilities $ 10,861 $ 9,603

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Summary of Fair Value Assets Associated with Pension Plan	The following table sets forth assets associated with the pension plan in “Note 15 – Retirement and Other Benefit Plans” that are accounted for at fair value by Level within the fair value hierarchy. Fair value as of December 31, 2018 (in thousands): December 31, 2108 Level 1 Level 2 Level 3 Total Mutual funds $ 2,539 $ - $ - $ 2,539 Fixed income - 10,168 - 10,168 Cash and cash equivalents 361 - - 361 $ 2,900 $ 10,168 $ - $ 13,068 Fair value as of March 31, 2019 (in thousands): March 31, 2109 Level 1 Level 2 Level 3 Total Mutual funds $ 2,715 $ - $ - $ 2,715 Fixed income - 10,689 - 10,689 Cash and cash equivalents 264 - - 264 $ 2,979 $ 10,689 $ - $ 13,667
Schedule of Fair Value of Redeemable Common Stock Associated Employee Stock Ownership Plan	The following table sets forth redeemable common stock associated with the ESOP in as described in “Note 14 – Retirement and Other Benefit Plans” that is accounted for at fair value by Level within the fair value hierarchy. Fair value as of December 31, 2018 (in thousands): December 31, 2108 Level 1 Level 2 Level 3 Total Redeemable common stock $ - $ - $ 1,876,309 $ 1,876,309 Fair value as of March 31, 2019 (in thousands): March 31, 2109 Level 1 Level 2 Level 3 Total Redeemable common stock $ - $ - $ 1,875,332 $ 1,875,332
Schedule of Reconciliation Fair Value Measurements Using Significant Unobservable Inputs	The following tables present a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs (Level 3) (in thousands): Balance at December 31, 2018 $ 1,876,309 Purchases of treasury stock (813 ) Share price adjustment (164 ) Balance at March 31, 2019 $ 1,875,332

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares Used To Compute Basic and Diluted EPS	The weighted average number of shares used to compute basic and diluted EPS were (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Basic weighted average number of shares outstanding 81,846,305 78,161,484 Dilutive common share equivalents - - Diluted weighted average number of shares outstanding 81,846,305 78,161,484

Segments Information (Tables)

Segments Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Summary of Business Segment Information	The following table summarizes business segment revenue for the periods presented (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Federal Solutions revenue $ 291,335 $ 422,812 Critical Infrastructure revenue 463,344 481,593 Total revenue $ 754,679 $ 904,405
Summary of Adjusted EBITDA Business Segment Information	The following table reconciles business segment Adjusted EBITDA attributable to Parsons Corporation to Net Income attributable to Parsons Corporation for the periods presented (in thousands): Three Months Ended Adjusted EBITDA attributable to Parsons Corporation March 30, 2018 March 31, 2019 Federal Solutions $ 20,154 $ 38,866 Critical Infrastructure 23,656 25,559 Adjusted EBITDA attributable to Parsons Corporation 43,810 64,425 Adjusted EBITDA attributable to noncontrolling interests 3,920 3,749 Depreciation and amortization (9,009 ) (30,591 ) Interest expense, net (3,258 ) (7,815 ) Income tax expense (5,353 ) (1,886 ) Litigation-related expenses(a) (2,330 ) - Amortization of deferred gain resulting from sale-leaseback transactions(b) 1,813 - Transaction-related costs(c) (125 ) (9,355 ) Restructuring(d) - (2,218 ) HCM software implementation costs(e) - (2,912 ) Other(f) (366 ) (11 ) Net income including noncontrolling interests 29,102 13,386 Net income attributable to noncontrolling interests 3,815 3,645 Net income attributable to Parsons Corporation $ 25,287 $ 9,741 (a) Reflects interest expense in “(Interest and other expenses) gain associated with claim on long-term contract” in our results of operations associated with a lawsuit against a joint venture in which the Company is the managing partner. Please see “Note 14 – Commitments and Contingencies” in the Company’s Form S-1/A filed on April 29, 2019, for a description of this matter, which was resolved in favor of the Company on June 13, 2018. (b) Reflects recognized deferred gains related to sales-leaseback transactions described in “Note 11 – Sale-Leasebacks.” (c) Reflects costs incurred in connection with acquisitions, initial public offering, and other non-recurring transaction costs, primarily fees paid for professional services and employee retention. (d) Reflects costs associated with our corporate restructuring initiatives. (e) Reflects implementation costs incurred in connection with a new human resources and payroll application. (f) Includes a loss from sale of a subsidiary and other individually insignificant items that are non-recurring in nature for the quarter ended March 30, 2018, and a combination of gain/loss related to sale of fixed assets and other individually insignificant items that are non-recurring in nature for the quarter ended March 31, 2019.
Summary of Revenues and Property and Equipment, Net by Geographic Area	The following tables presents revenues and property and equipment, net by geographic area (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Revenue North America $ 587,307 $ 731,030 Middle East 162,406 167,952 Rest of World 4,966 5,423 Total Revenue $ 754,679 $ 904,405 The geographic location of revenue is determined by the location of the customer. Three Months Ended December 31, 2018 March 31, 2019 Property and Equipment, Net North America $ 86,847 $ 92,262 Middle East 5,002 5,036 Total Property and Equipment, Net $ 91,849 $ 97,298
Summary of Revenues by Business Lines	The following table presents revenues by business lines (in thousands): Three Months Ended March 30, 2018 March 31, 2019 Revenue Cyber & Intelligence $ 44,367 $ 76,110 Defense 73,540 134,990 Mission Solutions 74,149 68,090 Engineered Systems 99,279 114,666 Geospatial - 28,956 Federal Solutions revenues 291,335 422,812 Connect Communities 160,913 156,876 Mobility Solutions 255,679 269,114 Industrial 46,752 55,603 Critical Infrastructure revenues 463,344 481,593 Total Revenue $ 754,679 $ 904,405

Description of Operations - Add

Description of Operations - Additional Information (Details) - Subsequent Event - USD ($)	May 31, 2019	May 14, 2019	May 08, 2019	Apr. 15, 2019
Description Of Operations Disclosure [Line Items]
Funds to dividend through public offering		$ 52,100,000
Repayment on term loan through public offering		$ 150,000
Common stock dividend ratio				200.00%
Dividends payment, date				May 8, 2019
Initial Public Offering | Common Stock
Description Of Operations Disclosure [Line Items]
Common stock shares sold			18,518,500
Common stock sold per share			$ 27
Share price		$ 25.515
Proceeds from initial public offering		$ 533,800,000
Underwriters | Common Stock
Description Of Operations Disclosure [Line Items]
Purchase of additional shares upon exercise of options	2,777,775
Underwriting discount per share		$ 1.485
Proceeds from initial public offering		$ 533,800,000

New Accounting Pronouncements -

New Accounting Pronouncements - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Dec. 30, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Retained earnings	$ 75,771	$ 12,445
Difference between Revenue Guidance in Effect before and after Topic 606 | ASC 606
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Retained earnings			$ 4,700

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - USD ($)	Jan. 07, 2019	May 31, 2018	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Amortization of intangible assets			$ 1,800,000	$ 20,900,000
Goodwill			921,097,000		$ 736,938,000
Revenues			904,405,000	$ 754,679,000
Polaris Alpha
Business Acquisition [Line Items]
Percentage of ownership interest acquired		100.00%
Cash paid to acquire		$ 489,100,000
Borrowed under credit agreement to partially fund the acquisition		260,000,000
Amortization of intangible assets			13,700,000
Goodwill		$ 243,471,000	243,500,000
Goodwill deductible for tax purposes			0
Revenues			93,400,000
Polaris Alpha | Indirect, General and Administrative Expense
Business Acquisition [Line Items]
Acquisition related expenses					$ 6,200,000
OGSystems
Business Acquisition [Line Items]
Percentage of ownership interest acquired	100.00%
Cash paid to acquire	$ 292,400,000
Borrowed under credit agreement to partially fund the acquisition	110,000,000
Amortization of intangible assets			5,900,000
Goodwill	183,567,000		183,600,000
Goodwill deductible for tax purposes			16,000,000
Revenues			29,000,000
OGSystems | Term Loan
Business Acquisition [Line Items]
Borrowed under credit agreement to partially fund the acquisition	$ 150,000,000
OGSystems | Indirect, General and Administrative Expense
Business Acquisition [Line Items]
Acquisition related expenses			$ 4,100,000

Acquisitions - Summary of Estim

Acquisitions - Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed on Preliminary Purchase Price Allocation (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 07, 2019	Dec. 31, 2018	May 31, 2018
Business Acquisition [Line Items]
Contract assets	$ 571,755		$ 515,319
Goodwill	921,097		736,938
Contract liabilities	(225,017)		$ (208,576)
Polaris Alpha
Business Acquisition [Line Items]
Cash and cash equivalents				$ 7,914
Accounts receivable				29,688
Contract assets				35,229
Prepaid expenses and other current assets				9,295
Property and equipment				9,024
Goodwill	243,500			243,471
Intangible assets				199,520
Other noncurrent assets				2,203
Accounts payable				(13,942)
Accrued expenses and other current liabilities				(26,419)
Contract liabilities				(3,529)
Deferred tax liabilities				(2,231)
Other long-term liabilities				(1,146)
Net assets acquired				$ 489,077
OGSystems
Business Acquisition [Line Items]
Cash and cash equivalents		$ 5,772
Accounts receivable		9,904
Contract assets		9,747
Prepaid expenses and other current assets		4,307
Property and equipment		4,085
Right of use assets, operating leases		8,826
Goodwill	$ 183,600	183,567
Intangible assets		92,300
Other noncurrent assets		10
Accounts payable		(5,450)
Accrued expenses and other current liabilities		(7,147)
Contract liabilities		(1,300)
Short-term lease liabilities, operating leases		(805)
Income tax payable		(1,469)
Deferred tax liabilities		(931)
Long-term lease liabilities, operating leases		(8,021)
Other long-term liabilities		(1,015)
Net assets acquired		$ 292,380

Acquisitions - Schedule of Inta

Acquisitions - Schedule of Intangible Assets Value on Purchase Price (Details) - USD ($) $ in Thousands	Jan. 07, 2019	May 31, 2018	Mar. 31, 2019
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)			4 years
Developed Technology | Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 84,900
Amortization Period (in years)		4 years
Developed Technology | OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,300
Amortization Period (in years)	3 years
Customer Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)			7 years
Customer Relationships | Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 76,000
Amortization Period (in years)		8 years
Customer Relationships | OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 57,100
Amortization Period (in years)	5 years
Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)			3 years
Backlog | Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 34,900
Amortization Period (in years)		2 years
Backlog | OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 27,700
Amortization Period (in years)	3 years
Trade Name
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)			1 year
Trade Name | Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 3,600
Amortization Period (in years)		1 year
Trade Name | OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,800
Amortization Period (in years)	2 years
Non compete Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)			2 years
Non compete Agreements | OGSystems
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,400
Amortization Period (in years)	3 years
Leases
Acquired Finite Lived Intangible Assets [Line Items]
Amortization Period (in years)			5 years
Leases | Polaris Alpha
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 120
Amortization Period (in years)		6 years

Acquisitions - Schedule of Supp

Acquisitions - Schedule of Supplemental Pro Forma Information (Unaudited) (Details) - Polaris Alpha $ in Thousands	3 Months Ended
	Mar. 30, 2018USD ($)
Business Acquisition [Line Items]
Pro forma revenue	$ 840,487
Pro forma net income	$ 10,532

Contracts with Customers - Summ

Contracts with Customers - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 904,405	$ 754,679
Fixed-Price
Disaggregation Of Revenue [Line Items]
Revenues	257,695	265,408
Time-and-Materials
Disaggregation Of Revenue [Line Items]
Revenues	255,706	227,741
Cost-Plus
Disaggregation Of Revenue [Line Items]
Revenues	$ 391,004	$ 261,530

Contracts with Customers - Su_2

Contracts with Customers - Summary of Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Contract assets	$ 571,755	$ 515,319
Contract liabilities	225,017	208,576
Net contract assets (liabilities)	346,738	$ 306,743
Change in contract assets	56,436
Change in contract liabilities	16,441
Change in contract assets and liabilities	$ 39,995
Percentage change in contract assets	11.00%
Percentage change in contract liabilities	7.90%
Percentage change in contract assets and liabilities	13.00%

Contracts with Customers - Su_3

Contracts with Customers - Summary of Contract Assets and Contract Liabilities (Parenthetical) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Contract retentions	$ 90	$ 89.6
Contract retentions, not expected to be paid in next 12 months	34.8
Contract assets, unapproved change orders, claims, and requests	$ 49.4	$ 47.1

Contracts with Customers - Addi

Contracts with Customers - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Revenue From Contract With Customer [Abstract]
Revenue recognized included contract liability	$ 85,700,000	$ 26,300,000
Impairment of contract assets	0
Revenue recognized from unapproved change orders and claims	4,500,000	$ 18,700,000
Remaining unsatisfied performance obligations	$ 5,300,000,000

Contracts with Customers - Su_4

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

Contracts with Customers - Su_5

Contracts with Customers - Summary of Change in Contract Assets and Contract Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Reversal for provision for contract losses	$ 0	$ 133,180
Increase in revenue recorded in other income		$ 55,100

Contracts with Customers - Su_6

Contracts with Customers - Summary of Remaining Unsatisfied Performance Obligations Expect to Satisfy (Details) $ in Thousands	Mar. 31, 2019USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 5,300,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 2,543,046
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,360,990
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,423,225
Revenue, remaining performance obligation, expected timing of satisfaction, period
Federal Solution Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 982,972
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Federal Solution Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 577,405
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Federal Solution Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 324,510
Revenue, remaining performance obligation, expected timing of satisfaction, period
Critical Infrastructure | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,560,074
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Critical Infrastructure | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 783,585
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Critical Infrastructure | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-04-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Remaining unsatisfied performance obligations	$ 1,098,715
Revenue, remaining performance obligation, expected timing of satisfaction, period

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 31, 2019	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Lessee Lease Description [Line Items]
Lease option to extend			five years
Lease existence of option to extend			true
Lease option to terminate			seventh year
Lease existence of option to terminate			true
Finance lease right-of-use asset	$ 1,341		$ 1,341
Finance lease right of use assets accumulated depreciation	200		$ 200
Operating lease not yet commenced expense	$ 6,200
Minimum rental commitments on operating leases, current					$ 276,700
Minimum rental commitments on operating leases, 2019					67,900
Minimum rental commitments on operating leases, 2020					51,000
Minimum rental commitments on operating leases, 2021					42,500
Minimum rental commitments on operating leases, 2022					35,900
Minimum rental commitments on operating leases, 2023					29,400
Minimum rental commitments on operating leases, thereafter					$ 50,000
Rent expense				$ 18,200
Minimum [Member]
Lessee Lease Description [Line Items]
Lease term of contract			1 year
Operating lease not yet commenced term of contract	4 years		4 years
Maximum [Member]
Lessee Lease Description [Line Items]
Lease term of contract			11 years
Operating lease not yet commenced term of contract	6 years		6 years
Accounting Standards Update 2016-02
Lessee Lease Description [Line Items]
Cumulative effect adjustment to retained earnings			$ 52,608
Accounting Standards Update 2016-02 | Net Deferred Tax Asset
Lessee Lease Description [Line Items]
Cumulative effect adjustment to retained earnings			52,600
Accounting Standards Update 2016-02 | Deferred Tax Asset
Lessee Lease Description [Line Items]
Cumulative effect adjustment to retained earnings		$ 700	$ 700

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 18,285
Short-term lease cost	2,004
Amortization of right-of-use assets	225
Interest on lease liabilities	16
Sublease income	(930)
Total lease cost	$ 19,600

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Operating cash flows for operating leases	$ 18,333
Operating cash flows for financing activities	16
Financing cash flows for finance leases	246
Right-of-use assets operating leases	249,848
Finance lease right-of-use asset	$ 1,341

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Balance Sheet and Other Information Related to Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Operating Leases:
Right of use assets, operating leases	$ 216,484	$ 0
Lease liabilities:
Short-term lease liabilities, operating leases	53,029	0
Long-term lease liabilities, operating leases	181,274	$ 0
Total operating lease liabilities	234,303
Finance Leases:
Other noncurrent assets	1,341
Accrued expenses and other current liabilities	$ 521
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Other long-term liabilities	$ 798
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Weighted Average Remaining Lease Term:
Operating leases	6 years
Finance leases	3 years
Weighted Average Discount Rate:
Operating leases	4.50%
Finance leases	4.50%

Leases - Schedule of Maturity A

Leases - Schedule of Maturity Analysis of Future Undiscounted Cash Flows (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating Leases
2019	$ 47,084
2020	51,139
2021	44,062
2022	37,987
2023	30,997
Thereafter	53,870
Total lease payments	265,139
Less: imputed interest	(30,836)
Total present value of lease liabilities	234,303
Finance Leases
2019	427
2020	510
2021	353
2022	113
2023	0
Thereafter	0
Total lease payments	1,403
Less: imputed interest	(84)
Total present value of lease liabilities	$ 1,319

Accounts Receivable, Net - Summ

Accounts Receivable, Net - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Billed	$ 534,288	$ 538,808
Unbilled	164,034	135,180
Total accounts receivable, gross	698,322	673,988
Allowance for doubtful accounts	(46,398)	(50,702)
Total accounts receivable, net	$ 651,924	$ 623,286

Accounts Receivable, Net - Addi

Accounts Receivable, Net - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Unbilled accounts receivable	$ 164,034	$ 135,180
Unapproved Change Orders, Claims, Request
Accounts Notes And Loans Receivable [Line Items]
Unbilled accounts receivable	$ 49,400	$ 47,100

Goodwill - Summary of Changes i

Goodwill - Summary of Changes in Carrying Value of Goodwill by Reporting Segment (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Goodwill [Line Items]
Beginning Balance	$ 736,938
Acquisitions	183,500
Foreign Exchange	659
Ending Balance	921,097
Federal Solutions
Goodwill [Line Items]
Beginning Balance	666,841
Acquisitions	183,500
Foreign Exchange	0
Ending Balance	850,341
Critical Infrastructure
Goodwill [Line Items]
Beginning Balance	70,097
Acquisitions	0
Foreign Exchange	659
Ending Balance	$ 70,756

Intangible Assets - Schedule of

Intangible Assets - Schedule of Gross Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 387,067	$ 294,767
Accumulated Amortization	(136,119)	(115,249)
Net Carrying Amount	250,948	179,518
Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	108,454	80,754
Accumulated Amortization	(65,636)	(58,295)
Net Carrying Amount	$ 42,818	22,459
Amortization Period (in years)	3 years
Customer Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 178,729	121,629
Accumulated Amortization	(45,839)	(38,974)
Net Carrying Amount	$ 132,890	82,655
Amortization Period (in years)	7 years
Leases
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 670	670
Accumulated Amortization	(566)	(561)
Net Carrying Amount	$ 104	109
Amortization Period (in years)	5 years
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 89,139	87,839
Accumulated Amortization	(20,736)	(15,174)
Net Carrying Amount	$ 68,403	72,665
Amortization Period (in years)	4 years
Trade Name
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 7,400	3,600
Accumulated Amortization	(2,992)	(2,100)
Net Carrying Amount	$ 4,408	1,500
Amortization Period (in years)	1 year
Non compete Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,400	0
Accumulated Amortization	(200)	0
Net Carrying Amount	$ 2,200	0
Amortization Period (in years)	2 years
Other Intangibles
Acquired Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 275	275
Accumulated Amortization	(150)	(145)
Net Carrying Amount	$ 125	$ 130
Amortization Period (in years)	10 years

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 1.8	$ 20.9

Intangible Assets - Schedule _2

Intangible Assets - Schedule of Estimated Amortization Expense (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
2019 (remaining)	$ 61,883
2020	72,542
2021	68,401
2022	25,808
2023	15,999
Thereafter	6,315
Net Carrying Amount	$ 250,948	$ 179,518

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 30, 2018
Property Plant And Equipment [Line Items]
Accumulated depreciation	$ (214,896)	$ (204,533)
Property and equipment, net	97,298	91,849	$ 91,849
Buildings and Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 61,631	54,348
Buildings and Leasehold Improvements | Minimum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	1 year
Buildings and Leasehold Improvements | Maximum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	15 years
Furniture and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 86,174	81,705
Furniture and Equipment | Minimum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	3 years
Furniture and Equipment | Maximum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	10 years
Computer Systems and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 152,558	148,255
Computer Systems and Equipment | Minimum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	3 years
Computer Systems and Equipment | Maximum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	10 years
Construction Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 11,832	$ 12,074
Construction Equipment | Minimum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	5 years
Construction Equipment | Maximum [Member]
Property Plant And Equipment [Line Items]
Useful lives (years)	7 years

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Property Plant And Equipment [Abstract]
Depreciation expense	$ 9.7	$ 7.2

Sale-Leasebacks - Additional In

Sale-Leasebacks - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2019USD ($)	Mar. 31, 2019USD ($)	Mar. 30, 2018USD ($)	Dec. 31, 2011USD ($)building	Dec. 31, 2018USD ($)
Sale Leaseback Transaction [Line Items]
Sale leaseback transaction, description		During fiscal 2011, the Company consummated two sale-leaseback transactions associated with the sale of two office buildings
Number of sale leaseback transaction associated with sale | building				2
Gain recognized to the sale leaseback transaction				$ 106,700
Deferred gain resulting from sale-leaseback transactions		$ 0		$ 107,800	$ 46,004
Amortization of deferred gain		0	$ 1,800
Accounting Standards Update 2016-02
Sale Leaseback Transaction [Line Items]
Deferred gain balance recognized					$ 53,300
Cumulative effect adjustment to retained earnings		52,608
Accounting Standards Update 2016-02 | Deferred Tax Asset
Sale Leaseback Transaction [Line Items]
Cumulative effect adjustment to retained earnings	$ 700	$ 700

Debt and Credit Facilities - Sc

Debt and Credit Facilities - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-Term Debt issuance costs	$ (789)	$ (836)
Long-term debt	509,211	429,164
Term Loan	150,000	0
Short-Term Debt issuance costs	(214)	0
Total Short-Term	149,786	0
Total Debt	658,997	429,164
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	260,000	180,000
Senior Notes
Debt Instrument [Line Items]
Long-term debt	$ 250,000	$ 250,000

Debt and Credit Facilities - Ad

Debt and Credit Facilities - Additional Information (Details) - USD ($)	May 10, 2019	Jul. 01, 2014	Jan. 31, 2019	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Debt issuance costs incurred				$ 500,000
Letters of credit outstanding amount				227,700,000		$ 223,000,000
Amortization of debt issue costs				244,000	$ 149,000
Term Loan
Debt Instrument [Line Items]
Interest expense				1,400,000
Debt Amount			$ 150,000,000		0
Term Loan | Subsequent Event
Debt Instrument [Line Items]
Repayment of outstanding balance	$ 150,000,000
Accrued Expenses and Other Current Liabilities
Debt Instrument [Line Items]
Interest payable				2,600,000		5,700,000
Senior Notes
Debt Instrument [Line Items]
Interest expense				3,100,000	3,100,000
Interest payments				6,200,000	6,200,000
Private Placement
Debt Instrument [Line Items]
Debt issuance costs incurred				$ 1,100,000
Repayment of outstanding balance		$ 250,000,000
Base Rate | Term Loan
Debt Instrument [Line Items]
Interest rate			0.25%
Debt instrument, interest rate terms			The Base Rate Loans bear interest at a rate per annum of the sum of (a) the highest of (1) the administrative agent’s reference rate; (2) the rate equal to 1.50% per annum above the Offshore Rate; and (3) the rate equal to 0.50% per annum above the latest federal funds rate, plus (b) 0.25%.
Debt instrument interest rate above the offshore rate			1.50
Debt instrument interest above the latest federal funds rate			0.50
Offshore Rate | Term Loan
Debt Instrument [Line Items]
Margin interest rate			1.25%
Debt instrument, interest rate terms			The Offshore Rate Loans bear interest at a rate per annum of LIBOR, divided by 1.00 minus the Eurodollar Reserve Percentage, plus 1.25%.
Credit Agreement
Debt Instrument [Line Items]
Amended and restated credit agreement date				Nov. 30, 2017
Debt issuance costs incurred				$ 2,000,000
Revolving credit facility				500,000,000
Increase in revolving credit facility				$ 550,000,000
Credit agreement extended date				Nov. 30, 2022
Letters of credit outstanding amount				$ 49,800,000	$ 0	$ 48,800,000
Interest expense				$ 3,400,000
Credit Agreement | Minimum
Debt Instrument [Line Items]
Interest rate				4.253%
Credit Agreement | Maximum
Debt Instrument [Line Items]
Interest rate						4.267%
Credit Agreement | Base Rate | Minimum
Debt Instrument [Line Items]
Margin interest rate				0.125%
Credit Agreement | Base Rate | Maximum
Debt Instrument [Line Items]
Margin interest rate				1.00%
Credit Agreement | LIBOR | Minimum
Debt Instrument [Line Items]
Margin interest rate				1.125%
Credit Agreement | LIBOR | Maximum
Debt Instrument [Line Items]
Margin interest rate				2.00%

Debt and Credit Facilities - _2

Debt and Credit Facilities - Schedule of Aggregate Amount Debt Repayable (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Senior Note, Series A
Debt Instrument [Line Items]
Debt Amount	$ 50,000
Maturity Date	Jul. 15, 2021
Interest Rates	4.44%
Senior Note, Series B
Debt Instrument [Line Items]
Debt Amount	$ 100,000
Maturity Date	Jul. 15, 2024
Interest Rates	4.98%
Senior Note, Series C
Debt Instrument [Line Items]
Debt Amount	$ 60,000
Maturity Date	Jul. 15, 2026
Interest Rates	5.13%
Senior Note, Series D
Debt Instrument [Line Items]
Debt Amount	$ 40,000
Maturity Date	Jul. 15, 2029
Interest Rates	5.38%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 30, 2018	Dec. 29, 2017	Dec. 31, 2018
Income Taxes [Line Items]
Effective S Corporation tax rate percentage	12.35%	15.54%
U.S. corporate tax rate	21.00%		35.00%
Deferred tax assets valuation allowance	$ 6.7
Liability for income taxes associated with uncertain tax positions	10.7			$ 9.9
Minimum [Member]
Income Taxes [Line Items]
Estimated effects of change in tax status based upon forecasted temporary differences	55
Maximum [Member]
Income Taxes [Line Items]
Estimated effects of change in tax status based upon forecasted temporary differences	$ 61
California Franchise Tax Board
Income Taxes [Line Items]
S Corporation franchise tax rate on income	1.50%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Mar. 01, 2017USD ($)	Mar. 31, 2019Claim
Legal Proceedings [Line Items]
Number of claims outstanding | Claim		0
Minimum
Legal Proceedings [Line Items]
Loss contingency damages value | $	$ 100,000,000

Retirement and Other Benefit _2

Retirement and Other Benefit Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares fully vested, Description	Shares allocated to a participant’s account are fully vested after six years of credited service, or in the event(s) of reaching age 65, death or disability while an active employee of the Company.
Shares fully vested after credited service	6 years
Company's stock held by ESOP	78,138,831		78,172,809
ESOP shares aggregate redemption, value	$ 1,900		$ 1,900
Dividends declared	$ 0		$ 0
Contribution to 401 (k) plan	$ 4.7	$ 9.2
Other Noncurrent Assets
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Defined benefit pension plan, net assets position	1.7		$ 1.7
Direct Costs of Contracts and Indirect, General and Administrative Expense
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
ESOP contribution expense	$ 12.2	$ 11.2

Investments in and Advances t_3

Investments in and Advances to Joint Ventures - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Schedule Of Equity Method Investments [Line Items]
Letters of credit outstanding amount	$ 227,700		$ 223,000
Net distributions from unconsolidated joint ventures	10,794	$ 15,406
Unconsolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Net distributions from unconsolidated joint ventures	8,100	$ 12,300
Consolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Letters of credit outstanding amount	$ 77,200		$ 76,800

Investments in and Advances t_4

Investments in and Advances to Joint Ventures - Summary of Financial Information for Consolidated Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 1,431,161		$ 1,488,807
Total assets	3,032,998		2,612,578
Current liabilities	1,188,885		1,006,161
Total liabilities	2,028,306		1,657,345
Total joint venture equity	(902,468)		(967,537)
Revenues	904,405	$ 754,679
Costs	714,237	602,972
Net income attributable to Parsons Corporation	9,741	25,287
Net income attributable to noncontrolling interests	3,645	3,815
Consolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Current assets	269,856		287,227
Noncurrent assets	2,285		2,689
Total assets	272,141		289,916
Current liabilities	209,909		199,833
Total liabilities	209,909		199,833
Total joint venture equity	62,232		$ 90,083
Revenues	115,104	112,121
Costs	107,206	106,166
Net income attributable to Parsons Corporation	7,898	5,955
Net income attributable to noncontrolling interests	$ 3,645	$ 3,815

Investments in and Advances t_5

Investments in and Advances to Joint Ventures - Summary of Financial Information for Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 1,431,161		$ 1,488,807
Total assets	3,032,998		2,612,578
Current liabilities	1,188,885		1,006,161
Total liabilities	2,028,306		1,657,345
Total joint venture equity	(902,468)		(967,537)
Investments in and advances to unconsolidated joint ventures	67,202		63,560
Revenues	904,405	$ 754,679
Costs	714,237	602,972
Net income attributable to Parsons Corporation	9,741	25,287
Equity in earnings of unconsolidated joint ventures	10,397	11,031
Unconsolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Current assets	675,030		707,457
Noncurrent assets	894,191		876,385
Total assets	1,569,221		1,583,842
Current liabilities	487,933		560,306
Noncurrent liabilities	848,105		813,269
Total liabilities	1,336,038		1,373,575
Total joint venture equity	233,183		210,267
Investments in and advances to unconsolidated joint ventures	67,202		$ 63,560
Revenues	229,466	281,078
Costs	216,780	253,664
Net income attributable to Parsons Corporation	12,686	27,414
Equity in earnings of unconsolidated joint ventures	$ 10,397	$ 11,031

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - Unconsolidated joint ventures - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Related Party Transaction [Line Items]
Revenues	$ 33,600	$ 33,700
Reimbursable cost incurred	$ 27,200	$ 25,900

Related Party Transactions - Sc

Related Party Transactions - Schedule of Consolidated Balance Sheet Related to Services Provided to Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Contract assets	$ 571,755	$ 515,319
Contract liabilities	225,017	208,576
Unconsolidated Joint Ventures
Related Party Transaction [Line Items]
Accounts receivable	30,263	38,742
Contract assets	3,527	2,648
Contract liabilities	$ 9,603	$ 10,861

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Assets Associated with Pension Plan (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	$ 13,667	$ 13,068
Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,979	2,900
Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	10,689	10,168
Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Mutual Funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,715	2,539
Mutual Funds | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	2,715	2,539
Mutual Funds | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Mutual Funds | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Fixed Income
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	10,689	10,168
Fixed Income | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Fixed Income | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	10,689	10,168
Fixed Income | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Cash and Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	264	361
Cash and Cash Equivalents | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	264	361
Cash and Cash Equivalents | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	0	0
Cash and Cash Equivalents | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value disclosure	$ 0	$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Summary of Redeemable Common Stock Associated with ESOP (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable common stock	$ 1,875,332	$ 1,876,309
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable common stock	0	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable common stock	0	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Redeemable common stock	$ 1,875,332	$ 1,876,309

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Billions	Mar. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Shares held by ESOP	78,138,831	78,172,809
Shares held by ESOP, redemption values		$ 1.9

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Schedule of Reconciliation Fair Value Measurements Using Significant Unobservable Inputs (Details) - Level 3 $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2018	$ 1,876,309
Purchases of treasury stock	(813)
Share price adjustment	(164)
Balance at March 31, 2019	$ 1,875,332

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Earnings Per Share [Abstract]
Dilutive securities outstanding	0	0

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Weighted Average Number of Shares Used To Compute Basic and Diluted EPS (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Earnings Per Share [Abstract]
Basic weighted average number of shares outstanding	78,161,484	81,846,305
Dilutive common share equivalents	0	0
Diluted weighted average number of shares outstanding	78,161,484	81,846,305

Segments Information - Addition

Segments Information - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)segment	Mar. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Revenues	$ 904,405	$ 754,679
Property and equipment, net	97,298	91,849	$ 91,849
United States
Segment Reporting Information [Line Items]
Revenues	669,200	$ 540,500
Property and equipment, net	$ 86,200		$ 79,900

Segments Information - Summary

Segments Information - Summary of Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Segment Reporting Information [Line Items]
Total revenue	$ 904,405	$ 754,679
Federal Solution Segment
Segment Reporting Information [Line Items]
Total revenue	422,812	291,335
Critical Infrastructure
Segment Reporting Information [Line Items]
Total revenue	$ 481,593	$ 463,344

Segments Information - Summar_2

Segments Information - Summary of Adjusted EBITDA Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Adjusted EBITDA attributable to Parsons Corporation
Adjusted EBITDA attributable to Parsons Corporation	$ 64,425	$ 43,810
Adjusted EBITDA attributable to noncontrolling interests	3,749	3,920
Depreciation and amortization	(30,591)	(9,009)
Interest expense, net	(7,815)	(3,258)
Income tax provision	(1,886)	(5,353)
Litigation related expenses		(2,330)
Amortization of deferred gain resulting from sale-leaseback transactions		1,813
Transaction related costs	(9,355)	(125)
Restructuring	(2,218)
HCM software implementation costs	(2,912)
Other	(11)	(366)
Net income including noncontrolling interests	13,386	29,102
Net income attributable to noncontrolling interests	3,645	3,815
Net income attributable to Parsons Corporation	9,741	25,287
Federal Solution Segment
Adjusted EBITDA attributable to Parsons Corporation
Adjusted EBITDA attributable to Parsons Corporation	38,866	20,154
Critical Infrastructure
Adjusted EBITDA attributable to Parsons Corporation
Adjusted EBITDA attributable to Parsons Corporation	$ 25,559	$ 23,656

Segments Information - Summar_3

Segments Information - Summary of Revenues and Property and Equipment, Net by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 904,405	$ 754,679
Property and Equipment, Net	97,298	91,849	$ 91,849
North America
Segment Reporting Information [Line Items]
Revenues	731,030	587,307
Property and Equipment, Net	92,262	86,847
Middle East
Segment Reporting Information [Line Items]
Revenues	167,952	162,406
Property and Equipment, Net	5,036	5,002
Rest of World
Segment Reporting Information [Line Items]
Revenues	$ 5,423	$ 4,966

Segments Information - Summar_4

Segments Information - Summary of Revenues by Business Lines (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 904,405	$ 754,679
Federal Solution Segment
Segment Reporting Information [Line Items]
Revenues	422,812	291,335
Federal Solution Segment | Cyber & Intelligence
Segment Reporting Information [Line Items]
Revenues	76,110	44,367
Federal Solution Segment | Defense
Segment Reporting Information [Line Items]
Revenues	134,990	73,540
Federal Solution Segment | Mission Solutions
Segment Reporting Information [Line Items]
Revenues	68,090	74,149
Federal Solution Segment | Engineered Systems
Segment Reporting Information [Line Items]
Revenues	114,666	99,279
Federal Solution Segment | Geospatial
Segment Reporting Information [Line Items]
Revenues	28,956	0
Critical Infrastructure
Segment Reporting Information [Line Items]
Revenues	481,593	463,344
Critical Infrastructure | Connect Communities
Segment Reporting Information [Line Items]
Revenues	156,876	160,913
Critical Infrastructure | Mobility Solutions
Segment Reporting Information [Line Items]
Revenues	269,114	255,679
Critical Infrastructure | Industrial
Segment Reporting Information [Line Items]
Revenues	$ 55,603	$ 46,752

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event - USD ($) $ / shares in Units, $ in Millions	Apr. 15, 2019	Apr. 15, 2019	Apr. 03, 2019
Subsequent Event [Line Items]
Dividends payment, date	May 8, 2019
Board of Directors
Subsequent Event [Line Items]
Common stock dividend ratio			2
Common stock dividend date			May 7, 2019
Initial public offering date			May 8, 2019
Common stock dividend payment date			May 8, 2019
IPO | Board of Directors
Subsequent Event [Line Items]
Dividends payable, amount per share	$ 2	$ 2
Dividends payable	$ 52.1	$ 52.1
Dividends payment, date		May 10, 2019