Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jun. 25, 2016	Jul. 01, 2017	Jun. 25, 2016
Change in Accounting Estimate [Line Items]
Operating income	$ 61,018	$ 53,093	$ 113,352	$ 101,025
Net income	$ 37,510	$ 32,314	$ 69,893	$ 61,498
Earnings per share	$ 0.89	$ 0.77	$ 1.67	$ 1.45
Diluted earnings per share	$ 0.89	$ 0.76	$ 1.66	$ 1.45
Development of Prior Year Self Insured Claims Estimates
Change in Accounting Estimate [Line Items]
Operating income	$ 307	$ 738	$ 203	$ 2,816
Net income	$ 189	$ 456	$ 125	$ 1,740
Earnings per share		$ 0.01		$ 0.04
Diluted earnings per share		$ 0.01		$ 0.04