Summary of Information Regarding Stock Options (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 28, 2019 USD ($) $ / shares shares
Number of Options
Beginning Balance, number of options | shares	89,114
Exercised, number of options | shares	(32,300)
Ending Balance, number of options | shares	56,814
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	49.30
Ending Balance, Weighted Average Exercise Price per Share | $ / shares	$ 51.08
Options Exercisable, Number of Options
Options exercisable at the ending, Number of Options | shares	56,814
Options Exercisable, Weighted Average Exercise Price per Share
Options exercisable at the ending, Weighted Average Exercise Price per Share | $ / shares	$ 51.08
Weighted Average Remaining Contractual Term (years)
Options outstanding at September 28, 2019	2 years 6 months
Options exercisable at September 28, 2019	2 years 6 months
Aggregate Intrinsic Value
Options outstanding at September 28, 2019 | $	$ 3,487
Options exercisable at September 28, 2019 | $	$ 3,487