Revenue Recognition (Tables)

3 Months Ended

Mar. 31, 2023

Revenue From Contract With Customer [Abstract]

Disaggregation of Revenue

	Three Months Ended March 31,
	2023					2022
	Dollars		Percent			Dollars		Percent
Client Markets:
Energy, environment, infrastructure, and disaster recovery	$	187,396		39	%	$	169,028		41	%
Health and social programs		203,698		42	%		156,057		38	%
Security and other civilian & commercial		92,188		19	%		88,383		21	%
Total	$	483,282		100	%	$	413,468		100	%

	Three Months Ended March 31,
	2023					2022
	Dollars		Percent			Dollars		Percent
Client Type:
U.S. federal government	$	267,742		55	%	$	219,044		53	%
U.S. state and local government		74,933		16	%		66,117		16	%
International government		20,669		4	%		27,377		7	%
Total Government		363,344		75	%		312,538		76	%
Commercial		119,938		25	%		100,930		24	%
Total	$	483,282		100	%	$	413,468		100	%

	Three Months Ended March 31,
	2023					2022
	Dollars		Percent			Dollars		Percent
Contract Mix:
Time-and-materials	$	200,990		42	%	$	164,968		40	%
Fixed price		219,016		45	%		184,012		44	%
Cost-based		63,276		13	%		64,488		16	%
Total	$	483,282		100	%	$	413,468		100	%

Schedule of Contract Balances and Changes in Contract Balances

Contract Balances:

Contract assets consist primarily of unbilled amounts resulting from long-term contracts when revenue recognized exceeds the amount billed often due to billing schedule timing. Contract liabilities result from advance payments received on a contract or from billings in excess of revenue recognized on long-term contracts due to billing schedule timing.

The following table summarizes the contract balances as of March 31, 2023 and December 31, 2022:

	March 31, 2023			December 31, 2022
Contract assets	$	188,093		$	169,088
Contract liabilities		(25,771	)		(25,773	)
Net contract assets (liabilities)	$	162,322		$	143,315