Summary of Significant Accounting Policies - Weighted Average Number of Shares Outstanding Used to Compute Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Accounting Policies [Abstract]
Net earnings (loss)	$ 1,782	$ 6,619	$ (191)	$ 11,778
Weighted-average number of common shares outstanding
Basic weighted-average common shares outstanding	11,062	10,871	11,012	10,864
Dilutive potential common shares	214	174	0	258
Diluted weighted-average common shares outstanding	11,276	11,045	11,012	11,122
Earnings (loss) per share
Basic (in dollars per share)	$ 0.16	$ 0.61	$ (0.02)	$ 1.08
Diluted (in dollars per share)	$ 0.16	$ 0.60	$ (0.02)	$ 1.06