Summary of Information Regarding Stock Options (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 26, 2015 USD ($) $ / shares shares
Number of Options
Beginning Balance, number of options | shares	773,839
Exercised, number of options | shares	(111,105)
Forfeited, number of options | shares	(1,900)
Ending Balance, number of options | shares	660,834
Options exercisable at the ending, Number of Options | shares	436,434
Weighted Average Exercise Price per Share
Beginning Balance, Weighted Average Exercise Price per Share	$ 46.92
Exercised, Weighted Average Exercise Price per Share	45.60
Forfeited, Weighted Average Exercise Price per Share	53.17
Ending Balance, Weighted Average Exercise Price per Share	47.13
Options exercisable at September 26, 2015	$ 45.01
Weighted Average Remaining Contractual Term (years)
Options outstanding at September 26, 2015	5 years 1 month 6 days
Options exercisable at September 26, 2015	4 years 6 months
Aggregate Intrinsic Value
Options outstanding at September 26, 2015 | $	$ 13,385
Options exercisable at September 26, 2015 | $	$ 9,762