Equity - Schedule of Changes in Stockholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Beginning balance	$ 78,586	$ 78,107	$ 82,663	$ 73,266
Cumulative effect of accounting change	(1,634)		(1,634)
Common stock issued under employee plans	1,076	889	2,380	356
Grant of RSUs to settle accrued bonus				605
Equity-based compensation expense	852	1,148	2,454	2,910
Net income	(1,099)	1,230	(6,402)	4,159
Other comprehensive income (loss)	(73)	44	(119)	122
Ending balance	79,342	81,418	79,342	81,418
Common Stock and Additional Paid-in Capital [Member]
Beginning balance	180,449	174,267	177,543	171,335
Cumulative effect of accounting change		1,098		1,098
Common stock issued under employee plans	1,076	889	2,380	356
Grant of RSUs to settle accrued bonus				605
Equity-based compensation expense	852	1,148	2,454	2,910
Ending balance	182,377	176,304	182,377	176,304
Treasury Stock
Beginning balance	(28,489)	(28,489)	(28,489)	(28,489)
Ending balance	(28,489)	(28,489)	(28,489)	(28,489)
Accumulated Other Comprehensive Income
Beginning balance	444	399	490	321
Other comprehensive income (loss)	(73)	44	(119)	122
Ending balance	371	443	371	443
Accumulated Deficit
Beginning balance	(73,818)	(68,070)	(66,881)	(69,901)
Cumulative effect of accounting change	(1,634)	(1,098)	(1,634)	(1,098)
Net income	(1,099)	1,230	(6,402)	4,159
Ending balance	$ (74,917)	$ (66,840)	$ (74,917)	$ (66,840)