Goodwill - Summary of Changes in Carrying Value of Goodwill by Reporting Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Beginning Balance	$ 1,661,850	$ 1,412,690
Acquisitions	129,599	252,446
Foreign Exchange	1,216	(3,286)
Ending Balance	1,792,665	1,661,850
Federal Solutions
Goodwill [Line Items]
Beginning Balance	1,591,563	1,339,117
Acquisitions	95,338	252,446
Ending Balance	1,686,901	1,591,563
Critical Infrastructure
Goodwill [Line Items]
Beginning Balance	70,287	73,573
Acquisitions	34,261
Foreign Exchange	1,216	(3,286)
Ending Balance	$ 105,764	$ 70,287