Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net income including noncontrolling interests	$ 23,843	$ 14,014
Other comprehensive income, net of tax
Foreign currency translation adjustment, net of tax	2,874	4,914
Pension adjustments, net of tax	22	19
Comprehensive income including noncontrolling interests, net of tax	26,739	18,947
Comprehensive income attributable to noncontrolling interests, net of tax	(3,177)	(4,980)
Comprehensive income attributable to Parsons Corporation, net of tax	$ 23,562	$ 13,967