Summary of Stock Option Activity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 27, 2014
Options Outstanding
Outstanding, beginning balance	814,291
Granted	242,386
Forfeited	(28,209)
Exercised	(72,092)
Outstanding, ending balance	956,376
Options exercisable at end of period	499,833
Weighted-Average Exercise Price
Outstanding, beginning balance	$ 39.56
Granted	$ 57.07
Forfeited	$ 46.05
Exercised	$ 34.95
Outstanding, ending balance	$ 44.01
Options exercisable at end of period	$ 36.72
Weighted-Average Remaining Contractual Term
Outstanding at end of period	4 years 6 months
Options exercisable at end of period	3 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding at end of period	$ 10,167
Options exercisable at end of period	$ 8,560