Investments in and Advances to Joint Ventures - Summary of Financial Information for Consolidated Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 1,801,343		$ 1,719,783
Total assets	4,255,806		4,198,142
Current liabilities	1,140,071		1,108,119
Total liabilities	2,130,276		2,102,207
Total joint venture equity	2,063,879		2,043,570
Revenue	1,173,466	$ 949,069
Costs	917,188	733,900
Net income attributable to Parsons Corporation	25,553	20,667
Net income attributable to noncontrolling interests	9,723	3,176
Consolidated Joint Ventures
Schedule Of Equity Method Investments [Line Items]
Current assets	331,742		289,837
Noncurrent assets	10,693		9,961
Total assets	342,435		299,798
Current liabilities	216,682		194,701
Noncurrent liabilities	3,871		3,763
Total liabilities	220,553		198,464
Total joint venture equity	121,882		$ 101,334
Revenue	161,484	95,534
Costs	141,598	88,842
Net income attributable to Parsons Corporation	19,886	6,692
Net income attributable to noncontrolling interests	$ 9,723	$ 3,176