Summary of Information Regarding Stock Options (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 30, 2019 USD ($) $ / shares shares
Number of Options
Beginning Balance, number of options | shares	89,114
Exercised, number of options | shares	(16,400)
Ending Balance, number of options | shares	72,714
Weighted Average Exercise Price per Share
Beginning Balance, Weighted Average Exercise Price per Share | $ / shares	$ 50.44
Exercised, Weighted Average Exercise Price per Share | $ / shares	49.34
Ending Balance, Weighted Average Exercise Price per Share | $ / shares	$ 50.68
Options Exercisable, Number of Options
Options exercisable at the ending, Number of Options | shares	72,714
Options Exercisable, Weighted Average Exercise Price per Share
Options exercisable at the ending, Weighted Average Exercise Price per Share | $ / shares	$ 50.68
Weighted Average Remaining Contractual Term (years)
Options outstanding at March 30, 2019	2 years 10 months 24 days
Options exercisable at March 30, 2019	2 years 10 months 24 days
Aggregate Intrinsic Value
Options outstanding at March 30, 2019 | $	$ 4,269
Options exercisable at March 30, 2019 | $	$ 4,269