Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jul. 01, 2016	Apr. 01, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Data [Abstract]
Revenue	$ 74,644	$ 74,039	$ 75,521	$ 77,006	$ 77,492	$ 78,065	$ 83,486	$ 85,850	$ 301,210	$ 324,893	$ 369,478
Direct costs	59,476	61,010	61,864	62,777	62,639	64,193	67,574	71,305	245,127	265,711	302,318
Gross profit	15,168	13,029	13,657	14,229	14,853	13,872	15,912	14,545	56,083	59,182
Selling, general, and administrative expenses	13,657	12,619	12,940	12,923	13,140	14,567	14,026	13,467	52,139	55,200	56,523
Goodwill impairment charges						15,785		21,544		37,329
Operating income (loss)	1,511	410	717	1,306	1,713	(16,480)	1,886	(20,466)	3,944	(33,347)	10,637
Interest and other income (expense), net	320	(111)	(67)	(29)	(107)	77	(97)	(62)	113	(189)
Income (loss) before income taxes	1,831	299	650	1,277	1,606	(16,403)	1,789	(20,528)	4,057	(33,536)	10,729
Provision for income taxes	2,250	259	216	526	463	(220)	530	329	3,251	1,102	4,219
Net income (loss)	$ (419)	$ 40	$ 434	$ 751	$ 1,143	$ (16,183)	$ 1,259	$ (20,857)	$ 806	$ (34,638)	$ 6,510
Basic	$ (0.03)	$ 0.00	$ 0.03	$ 0.05	$ 0.07	$ (1.03)	$ 0.08	$ (1.34)	$ 0.05	$ (2.22)	$ 0.42
Diluted	$ (0.03)	$ 0.00	$ 0.03	$ 0.05	$ 0.07	(1.03)	0.08	(1.34)	$ 0.05	(2.22)	0.41
Cash dividend declared per share						$ 0.06	$ 0.06	$ 0.06		$ 0.18	$ 0.24