Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Revenue:
Total revenue	$ 73,840	$ 71,462	$ 222,222	$ 216,461
Cost of service:
Stock compensation expense	1,671	1,876	4,437	5,160
Total cost of service	48,869	47,817	146,753	144,827
Selling, general and administrative costs	15,690	14,877	46,738	45,612
Stock compensation expense	850	894	2,495	2,427
Acquisition-related contingent consideration liability	803		(3,750)
Restructuring				1,293
Total costs and operating expenses	66,212	63,588	192,236	194,159
Income from operations	7,628	7,874	29,986	22,302
Other expense:
Interest expense	(158)	(184)	(515)	(401)
Income from operations before income taxes	7,470	7,690	29,471	21,901
Income tax expense	2,313	2,401	5,426	3,988
Net income	$ 5,157	$ 5,289	$ 24,045	$ 17,913
Basic net income per common share:
Income per common share from operations	$ 0.17	$ 0.18	$ 0.82	$ 0.62
Weighted average common shares outstanding	29,478,243	28,764,661	29,332,508	28,891,301
Diluted net income per common share:
Income per common share from operations	$ 0.16	$ 0.17	$ 0.75	$ 0.56
Weighted average common and common equivalent shares outstanding	32,593,359	31,957,665	32,214,419	32,254,227
Revenue Before Reimbursements [Member]
Revenue:
Total revenue	$ 68,243	$ 65,947	$ 205,332	$ 198,742
Reimbursements [Member]
Revenue:
Total revenue	5,597	5,515	16,890	17,719
Cost of service:
Total cost of service	5,597	5,515	16,890	17,719
Cost Before Reimbursements [Member]
Cost of service:
Total cost of service	$ 41,601	$ 40,426	$ 125,426	$ 121,948