Revenue Recognition (Tables)

6 Months Ended

Jun. 30, 2019

Disaggregation Of Revenue [Abstract]

Disaggregation of Revenue

Disaggregation of Revenue

	Three Months Ended June 30,										Six Months Ended June 30,
	2019					2018					2019					2018
	Dollars		Percent			Dollars		Percent			Dollars		Percent			Dollars		Percent
Client Markets:
Energy, environment, and infrastructure	$	166,998		46	%	$	133,276		41	%	$	320,988		46	%	$	257,526		41	%
Health, education, and social programs		133,919		36	%		131,141		41	%		255,057		36	%		254,069		41	%
Safety and security		29,818		8	%		27,491		8	%		59,047		8	%		52,966		8	%
Consumer and financial services		35,982		10	%		32,407		10	%		72,879		10	%		62,534		10	%
Total	$	366,717		100	%	$	324,315		100	%	$	707,971		100	%	$	627,095		100	%

	Three Months Ended										Six Months Ended June 30,
	June 30, 2019					June 30, 2018					2019					2018
	Dollars		Percent			Dollars		Percent			Dollars		Percent			Dollars		Percent
Client Type:
U.S. federal government	$	141,193		38	%	$	139,517		43	%	$	273,363		39	%	$	273,750		44	%
U.S. state and local government		72,893		20	%		34,532		11	%		138,400		19	%		65,889		10	%
International government		31,652		9	%		34,615		11	%		58,865		8	%		63,383		10	%
Total Government		245,738		67	%		208,664		65	%		470,628		66	%		403,022		64	%
Commercial		120,979		33	%		115,651		35	%		237,343		34	%		224,073		36	%
Total	$	366,717		100	%	$	324,315		100	%	$	707,971		100	%	$	627,095		100	%

	Three Months Ended										Six Months Ended June 30,
	June 30, 2019					June 30, 2018					2019					2018
	Dollars		Percent			Dollars		Percent			Dollars		Percent			Dollars		Percent
Contract Mix:
Time-and-materials	$	167,457		46	%	$	128,103		39	%	$	323,459		46	%	$	252,290		40	%
Fixed price		146,516		40	%		136,220		42	%		280,119		40	%		258,609		41	%
Cost-based		52,744		14	%		59,992		19	%		104,393		14	%		116,196		19	%
Total	$	366,717		100	%	$	324,315		100	%	$	707,971		100	%	$	627,095		100	%

Schedule of Contract Balances and Changes in Contract Balances

Contract Balances:

	June 30, 2019			December 31, 2018			$ Change		% Change
Contract assets	$	141,960		$	126,688		$	15,272		12.1	%
Contract liabilities		(33,435	)		(33,494	)		59		(0.2	%)
Net contract assets (liabilities)	$	108,525		$	93,194		$	15,331		16.5	%