Consolidated Statements of Shareholder's Equity (Unaudited) - USD ($) $ in Thousands	Total	Revision of Prior Period, Accounting Standards Update, Adjustment	Common Stock	Treasury Stock	Additional Paid-in Capital	Additional Paid-in Capital Revision of Prior Period, Accounting Standards Update, Adjustment	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Revision of Prior Period, Accounting Standards Update, Adjustment	Accumulated Other Comprehensive Income (Loss)	Total Parsons Equity	Total Parsons Equity Revision of Prior Period, Accounting Standards Update, Adjustment	Noncontrolling Interest
Beginning balance at Dec. 31, 2020	$ 1,861,417		$ 146,609	$ (899,328)	$ 2,700,925		$ (120,569)		$ (13,865)	$ 1,813,772		$ 47,645
Beginning balance (ASU 2020-06) at Dec. 31, 2020		$ (37,220)				$ (40,002)		$ 2,782			$ (37,220)
Comprehensive income
Net income	14,014						9,039			9,039		4,975
Foreign currency translation gain (loss), net	4,914								4,909	4,909		5
Pension adjustments, net	19								19	19
Contributions	7											7
Distributions	(8,989)											(8,989)
Issuance of equity securities, net of retirements	(926)		45		(999)		28			(926)
Stock-based compensation	7,206				7,206					7,206
Ending Balance at Mar. 31, 2021	1,840,442		146,654	(899,328)	2,667,130		(108,720)		(8,937)	1,796,799		43,643
Beginning balance at Dec. 31, 2021	1,937,112		146,277	(867,391)	2,684,979		(53,529)		(9,568)	1,900,768		36,344
Comprehensive income
Net income	23,843						20,667			20,667		3,176
Foreign currency translation gain (loss), net	2,874								2,873	2,873		1
Pension adjustments, net	22								22	22
Contributions	1,226											1,226
Distributions	(8,309)											(8,309)
Issuance of equity securities, net of retirements	(4,493)		222		(4,719)		4			(4,493)
Repurchases of common stock	(5,548)		(151)		(5,397)					(5,548)
Stock-based compensation	3,898				3,898					3,898
Ending Balance at Mar. 31, 2022	$ 1,950,625		$ 146,348	$ (867,391)	$ 2,678,761		$ (32,858)		$ (6,673)	$ 1,918,187		$ 32,438