Summary of Information Regarding Stock Options (Detail) - $ / shares	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Number of Options
Beginning Balance, number of options	372,561	637,221	773,839
Exercised, number of options	(180,321)	(257,460)	(133,518)
Forfeited, number of options	(3,200)	(7,200)	(3,100)
Ending Balance, number of options	189,040	372,561	637,221
Weighted Average Exercise Price per Share
Beginning Balance, Weighted Average Exercise Price per Share	$ 48.24	$ 47.24	$ 46.92
Exercised, Weighted Average Exercise Price per Share	47.01	45.63	45.25
Forfeited, Weighted Average Exercise Price per Share	52.47	53.63	52.91
Ending Balance, Weighted Average Exercise Price per Share	$ 49.34	$ 48.24	$ 47.24
Options Exercisable, Number of Options
Options exercisable at the beginning, Number of Options	282,461	415,121	379,389
Options exercisable at the ending, Number of Options	169,240	282,461	415,121
Options Exercisable, Weighted Average Exercise Price per Share
Options exercisable at the beginning, Weighted Average Exercise Price per Share	$ 46.39	$ 45.12	$ 44.61
Options exercisable at the ending, Weighted Average Exercise Price per Share	$ 48.50	$ 46.39	$ 45.12