Quarterly Financial Data (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
Schedule Of Quarterly Financial Data [Line Items]
Revenue	$ 892,829		$ 787,938		$ 775,223		$ 711,644		$ 848,602		$ 841,726		$ 868,383		$ 762,380		$ 3,167,634	$ 3,321,091	$ 3,184,790
Operating income	63,765		58,461		53,093		47,932		62,648		63,980		66,033		49,045		223,251	241,706	224,372
Income before income taxes	62,696		57,513		52,205		47,043		61,907		63,266		65,320		48,264		219,457	238,757	221,195
Income taxes	23,122		21,235		19,891		17,859		24,052		23,918		24,849		18,249		82,107	91,068	82,386
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 common 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
Dividends per common share	$ 0.09		$ 0.09		$ 0.08		$ 0.08		$ 0.08		$ 0.08		$ 0.07		$ 0.07		$ 0.34	$ 0.30	$ 1.26

[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.