Revenue Recognition (Tables)

9 Months Ended

Sep. 30, 2019

Disaggregation Of Revenue [Abstract]

Disaggregation of Revenue

Disaggregation of Revenue

	Three Months Ended September 30,										Nine Months Ended September 30,
	2019					2018					2019					2018
	Dollars		Percent			Dollars		Percent			Dollars		Percent			Dollars		Percent
Client Markets:
Energy, environment, and infrastructure	$	172,217		46	%	$	147,914		44	%	$	492,509		46	%	$	404,870		42	%
Health, education, and social programs		138,699		37	%		126,424		38	%		394,288		36	%		381,063		40	%
Safety and security		29,682		8	%		29,478		9	%		88,913		8	%		82,444		8	%
Consumer and financial services		33,320		9	%		29,152		9	%		106,179		10	%		91,686		10	%
Total	$	373,918		100	%	$	332,968		100	%	$	1,081,889		100	%	$	960,063		100	%

	Three Months Ended										Nine Months Ended September 30,
	September 30, 2019					September 30, 2018					2019					2018
	Dollars		Percent			Dollars		Percent			Dollars		Percent			Dollars		Percent
Client Type:
U.S. federal government	$	148,181		40	%	$	140,276		42	%	$	421,287		39	%	$	413,599		43	%
U.S. state and local government		71,540		19	%		55,525		17	%		210,324		19	%		121,114		13	%
International government		28,020		7	%		26,559		8	%		86,885		8	%		89,950		9	%
Total Government		247,741		66	%		222,360		67	%		718,496		66	%		624,663		65	%
Commercial		126,177		34	%		110,608		33	%		363,393		34	%		335,400		35	%
Total	$	373,918		100	%	$	332,968		100	%	$	1,081,889		100	%	$	960,063		100	%

	Three Months Ended										Nine Months Ended September 30,
	September 30, 2019					September 30, 2018					2019					2018
	Dollars		Percent			Dollars		Percent			Dollars		Percent			Dollars		Percent
Contract Mix:
Time-and-materials	$	184,330		49	%	$	146,525		44	%	$	507,926		47	%	$	398,815		42	%
Fixed price		135,274		36	%		126,126		38	%		415,258		38	%		384,751		40	%
Cost-based		54,314		15	%		60,317		18	%		158,705		15	%		176,497		18	%
Total	$	373,918		100	%	$	332,968		100	%	$	1,081,889		100	%	$	960,063		100	%

Schedule of Contract Balances and Changes in Contract Balances

Contract Balances:

	September 30, 2019			December 31, 2018			$ Change		% Change
Contract assets	$	153,055		$	126,688		$	26,367		20.8	%
Contract liabilities		(32,086	)		(33,494	)		1,408		(4.2	%)
Net contract assets (liabilities)	$	120,969		$	93,194		$	27,775		29.8	%