Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income including noncontrolling interests	$ 290,665	$ 207,915	$ 126,565
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment, net of tax	(11,546)	2,375	(7,752)
Pension adjustments, net of tax	(131)	568	(547)
Comprehensive income including noncontrolling interests, net of tax	278,988	210,858	118,266
Comprehensive income attributable to noncontrolling interests, net of tax	(55,621)	(46,768)	(29,883)
Comprehensive income attributable to Parsons Corporation, net of tax	$ 223,367	$ 164,090	$ 88,383