Summary of Significant Accounting Policies - Weighted Average Number of Shares Outstanding Used to Compute Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Accounting Policies [Abstract]
Net earnings	$ 6,472	$ 5,504	$ 11,101	$ 9,211
Weighted-average number of common shares outstanding
Basic weighted-average common shares outstanding	10,871	10,648	10,864	10,624
Dilutive potential common shares	174	142	258	107
Diluted weighted-average common shares outstanding	11,045	10,790	11,122	10,731
Earnings Per Share
Basic (in dollars per share)	$ 0.60	$ 0.52	$ 1.02	$ 0.87
Diluted (in dollars per share)	$ 0.59	$ 0.51	$ 1.00	$ 0.86