Net Income Per Share - Computation of Basic and Diluted Net Income per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 24, 2014	Sep. 30, 2015	Sep. 24, 2014
Numerator:
Net income	$ 4,666	$ 25,849	$ 18,688	$ 37,888
Denominator:
Weighted-average shares outstanding—basic	38,275,317	34,221,829	37,837,610	30,549,979
Weighted-average shares outstanding—diluted	39,107,241	36,821,095	39,044,388	32,450,231
Net income per share—basic	$ 0.12	$ 0.76	$ 0.49	$ 1.24
Net income per share—diluted	$ 0.12	$ 0.70	$ 0.48	$ 1.17