Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Revenue:
Total revenue	$ 75,649	$ 73,570	$ 148,382	$ 144,999
Cost of service:
Stock compensation expense	923	1,842	2,766	3,284
Total cost of service	49,747	49,056	97,884	97,010
Selling, general and administrative costs	15,613	15,883	31,047	30,735
Stock compensation expense	804	874	1,646	1,533
Acquisition-related contingent consideration liability	(4,553)		(4,553)
Restructuring		1,293		1,293
Total costs and operating expenses	61,611	67,106	126,024	130,571
Income from operations	14,038	6,464	22,358	14,428
Other expense:
Interest expense	(178)	(127)	(357)	(217)
Income from operations before income taxes	13,860	6,337	22,001	14,211
Income tax expense	2,339	1,587	3,113	1,587
Net income	$ 11,521	$ 4,750	$ 18,888	$ 12,624
Basic net income per common share:
Income per common share from operations	$ 0.39	$ 0.16	$ 0.65	$ 0.44
Weighted average common shares outstanding	29,429,925	29,041,291	29,259,641	28,954,621
Diluted net income per common share:
Income per common share from operations	$ 0.36	$ 0.15	$ 0.59	$ 0.39
Weighted average common and common equivalent shares outstanding	32,235,085	32,512,601	32,024,949	32,402,508
Revenue Before Reimbursements [Member]
Revenue:
Total revenue	$ 69,614	$ 67,726	$ 137,089	$ 132,795
Reimbursements [Member]
Revenue:
Total revenue	6,035	5,844	11,293	12,204
Cost of service:
Total cost of service	6,035	5,844	11,293	12,204
Cost Before Reimbursements [Member]
Cost of service:
Total cost of service	$ 42,789	$ 41,370	$ 83,825	$ 81,522