v3.26.3
Investments in and Advances to Joint Ventures - Summary of Financial Information for Consolidated Joint Ventures (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Schedule Of Equity Method Investments [Line Items]          
Current assets $ 2,579,109   $ 2,579,109   $ 2,683,543
Total assets 5,985,237   5,985,237   5,769,534
Current liabilities 1,617,116   1,617,116   1,531,664
Total liabilities 3,237,080   3,237,080   3,001,862
Total joint venture equity 2,637,648   2,637,648   2,642,020
Revenue 1,650,548 $ 1,621,748 4,717,591 $ 4,760,431  
Costs 1,268,481 1,261,893 3,682,866 3,698,240  
Net income attributable to Parsons Corporation 54,153 64,123 91,860 185,556  
Net income attributable to noncontrolling interests 13,258 17,671 40,297 48,514  
Consolidated Joint Ventures          
Schedule Of Equity Method Investments [Line Items]          
Current assets 480,003   480,003   542,877
Noncurrent assets 6,305   6,305   7,961
Total assets 486,308   486,308   550,838
Current liabilities 269,649   269,649   301,891
Noncurrent liabilities 3,076   3,076   3,417
Total liabilities 272,725   272,725   305,308
Total joint venture equity 213,583   213,583   $ 245,530
Revenue 198,691 213,752 577,638 602,905  
Costs 172,046 178,123 496,643 505,145  
Net income attributable to Parsons Corporation 26,645 35,629 80,995 97,760  
Net income attributable to noncontrolling interests $ 13,258 $ 17,671 $ 40,297 $ 48,514