Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015	Jun. 25, 2016	Jun. 27, 2015
Change in Accounting Estimate [Line Items]
Operating income	$ 53,093	$ 66,033	$ 101,025	$ 115,078
Net income	$ 32,314	$ 40,471	$ 61,498	$ 70,486
Earnings per share	$ 0.77	$ 0.92	$ 1.45	$ 1.59
Diluted earnings per share	$ 0.76	$ 0.92	$ 1.45	$ 1.59
Development of Prior Year Self Insured Claims Estimates
Change in Accounting Estimate [Line Items]
Operating income	$ 738	$ 833	$ 2,816	$ 5,474
Net income	$ 456	$ 515	$ 1,740	$ 3,383
Earnings per share	$ 0.01	$ 0.01	$ 0.04	$ 0.08
Diluted earnings per share	$ 0.01	$ 0.01	$ 0.04	$ 0.08