Earnings Per Share - Summary of Basic and Diluted Weighted-Average Shares Outstanding (Detail) shares in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015 shares	Jun. 28, 2014 shares	Jul. 04, 2015 shares	Jun. 28, 2014 shares
Earnings Per Share [Abstract]
Weighted average shares - Basic (in shares)	22,100	21,684	22,055	21,616
Net effect of dilutive stock options (in shares)	736	954	765	1,032
Weighted average shares - Diluted (in shares)	22,836	22,638	22,820	22,648
Earnings Per Share
Date of payment of dividend to shareholders			Sep. 05, 2014
Convertible Class B Stock
Earnings Per Share
Stock distribution			0.20