Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 01, 2017	Mar. 26, 2016
Change in Accounting Estimate [Line Items]
Operating income	$ 52,334	$ 47,932
Net income	$ 32,383	$ 29,184
Earnings per share	$ 0.77	$ 0.69
Diluted earnings per share	$ 0.77	$ 0.69
Development of Prior Year Self Insured Claims Estimates
Change in Accounting Estimate [Line Items]
Operating income	$ (104)	$ 2,078
Net income	$ (64)	$ 1,284
Earnings per share		$ 0.03
Diluted earnings per share		$ 0.03