Net Income Per Share - Summary of Reconciliation of Numerators and Denominators of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014	Dec. 28, 2014
Basic net income per share:
Net income	$ 31,986	$ 26,065	$ 100,775	$ 89,949	$ 107,692
Weighted average shares outstanding	153,585	150,241	153,071	149,227
Basic net income per share	$ 0.21	$ 0.17	$ 0.66	$ 0.60
Diluted net income per share:
Net income	$ 31,986	$ 26,065	$ 100,775	$ 89,949	$ 107,692
Weighted average shares outstanding	153,585	150,241	153,071	149,227
Dilutive effect of equity-based awards:
Assumed exercise of options to purchase shares	2,360	4,065	2,739	4,652
Weighted average shares and equivalent shares outstanding	155,952	154,306	155,841	153,879
Diluted net income per share	$ 0.21	$ 0.17	$ 0.65	$ 0.58
RSUs [Member]
Dilutive effect of equity-based awards:
Restricted stock units	7		31