Computation of EPS, Basic and Diluted (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Earnings Per Share [Line Items]
Net income	$ 33,257	$ 32,304
Basic weighted average common shares outstanding	17,365	17,784
Potential common shares for restricted stock	102	65
Diluted weighted average common shares outstanding	17,467	17,849
Earnings per share:
Basic	$ 1.92	$ 1.82
Diluted	$ 1.90	$ 1.81