Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Revenue	$ 93,129	$ 90,260	$ 92,667	$ 82,713	$ 74,644	$ 74,039	$ 75,521	$ 77,006	$ 358,769	$ 301,210	$ 324,893
Direct costs	75,391	72,935	75,082	66,874	59,500	61,093	61,864	62,777	290,282	245,234	265,711
Gross profit	17,738	17,325	17,585	15,839	15,144	12,946	13,657	14,229	68,487	55,976
Selling, general, and administrative expenses	18,527	16,560	16,064	15,256	13,572	12,562	12,845	12,829	66,407	51,808	54,784
Operating income (loss)	(789)	765	1,521	583	1,572	384	812	1,400	2,080	4,168	(32,931)
Interest and other income (expense), net	(169)	630	(218)	(54)	259	(85)	(162)	(123)	189	(111)
Income (loss) before income taxes	(958)	1,395	1,303	529	1,831	299	650	1,277	2,269	4,057	(33,536)
Provision for income taxes	4,301	307	363	115	2,250	259	216	526	5,086	3,251	1,102
Net income (loss)	$ (5,259)	$ 1,088	$ 940	$ 414	$ (419)	$ 40	$ 434	$ 751	$ (2,817)	$ 806	$ (34,638)
Basic	$ (0.39)	$ 0.09	$ 0.07	$ 0.03	$ (0.03)	$ 0.00	$ 0.03	$ 0.05	$ (0.20)	$ 0.05	$ (2.22)
Diluted	$ (0.39)	$ 0.09	$ 0.07	$ 0.03	$ (0.03)	$ 0.00	$ 0.03	$ 0.05	$ (0.20)	$ 0.05	$ (2.22)