Earnings Per Share - Schedule of Computation of Basic Earnings per Share and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014
Numerator:
Net income	$ 26,060	$ 24,536	$ 70,542	$ 71,331
Denominator:
Weighted average basic shares outstanding	35,514	35,898	35,535	36,217
Effect of stock-based compensation awards	61	126	76	155
Weighted average diluted shares outstanding	35,575	36,024	35,611	36,372
Earnings Per Share:
Basic	$ 0.73	$ 0.68	$ 1.99	$ 1.97
Diluted	$ 0.73	$ 0.68	$ 1.98	$ 1.96