Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Sep. 24, 2016		Jun. 25, 2016		Mar. 26, 2016		Dec. 26, 2015		Sep. 26, 2015		Jun. 27, 2015		Mar. 28, 2015		Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Change in Accounting Estimate [Line Items]
Operating income	$ 63,765		$ 58,461		$ 53,093		$ 47,932		$ 62,648		$ 63,980		$ 66,033		$ 49,045		$ 223,251	$ 241,706	$ 224,372
Net income	$ 39,574		$ 36,278		$ 32,314		$ 29,184		$ 37,855		$ 39,348		$ 40,471		$ 30,015		$ 137,350	$ 147,689	$ 138,809
Earnings per share	$ 0.95	[1]	$ 0.86	[1]	$ 0.77	[1]	$ 0.69	[1]	$ 0.89	[1]	$ 0.91	[1]	$ 0.92	[1]	$ 0.67	[1]	$ 3.26	$ 3.38	$ 3.09
Diluted earnings per share	$ 0.94	[1]	$ 0.86	[1]	$ 0.76	[1]	$ 0.69	[1]	$ 0.88	[1]	$ 0.90	[1]	$ 0.92	[1]	$ 0.67	[1]	$ 3.25	$ 3.37	$ 3.07
Development of Prior Year Self Insured Claims Estimates
Change in Accounting Estimate [Line Items]
Operating income																	$ 1,079	$ 4,852	$ 6,664
Net income																	$ 667	$ 2,999	$ 4,118
Earnings per share																	$ 0.02	$ 0.07	$ 0.09
Diluted earnings per share																	$ 0.02	$ 0.07	$ 0.09

[1] Due to the changes in the number of average common shares and common stock equivalents outstanding during the year, the sum of earnings per share amounts for each quarter do not necessarily sum in the aggregate to the earnings per share amounts for the full year.