Number of Unvested Restricted Stock Unit Awards Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 28, 2018	Dec. 29, 2017	Dec. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value, awards granted		$ 40.61	$ 29.50	$ 24.14
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, awards balance	[1]	1,185,184
Number of shares outstanding, awards granted	[1]	421,463
Number of shares outstanding, awards vested	[1]	(571,257)
Number of shares outstanding, awards forfeited	[1]	(851)
Number of shares outstanding, awards balance	[1]	1,034,539	1,185,184
Weighted-average grant date fair value, awards balance	[1]	$ 22.96
Weighted-average grant date fair value, awards granted	[1]	40.61
Weighted-average grant date fair value, awards vested	[1]	27.28
Weighted-average grant date fair value, awards forfeited	[1]	24.60
Weighted-average grant date fair value, awards balance	[1]	$ 27.76	$ 22.96
Weighted average remaining contractual term, Balance	[1]	1 year 7 months 6 days
Aggregate intrinsic value, Balance	[1],[2]	$ 51,644

[1] Does not include employee stock purchase plans or stock option plans.

[2] The intrinsic value is calculated as the market value as of the end of the fiscal period. As reported by the NASDAQ Global Select Market, the market value as of December 28, 2018 was $49.92.