Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015
Change in Accounting Estimate [Line Items]
Operating income	$ 58,461	$ 63,980	$ 159,486	$ 179,058
Net income	$ 36,278	$ 39,348	$ 97,776	$ 109,834
Earnings per share	$ 0.86	$ 0.91	$ 2.32	$ 2.50
Diluted earnings per share	$ 0.86	$ 0.90	$ 2.31	$ 2.49
Development of Prior Year Self Insured Claims Estimates
Change in Accounting Estimate [Line Items]
Operating income	$ (2,118)	$ 47	$ 698	$ 5,521
Net income	$ (1,309)	$ 29	$ 431	$ 3,412
Earnings per share	$ (0.03)	$ 0.00	$ 0.01	$ 0.08
Diluted earnings per share	$ (0.03)	$ 0.00	$ 0.01	$ 0.08