Restatement of Previously Issued Financial Statements (Summary of Corrections by Financial Statement Line Item) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 23, 2012		Sep. 25, 2011	Sep. 23, 2012		Sep. 25, 2011		Dec. 25, 2011	Dec. 26, 2010
As Previously Reported [Member]
Consolidated Statement of Stockholders' Equity
Retained earnings	$ 343,471		$ 282,826	$ 343,471		$ 282,826		$ 298,807	$ 243,152
Noncontrolling interests in subsidiaries	9,430		8,245	9,430		8,245		8,569	8,506
Total stockholders' equity	217,806		212,554	217,806		212,554		218,222	207,200
Condensed Consolidated Balance Sheet
Noncurrent deferred income tax liabilities	10,508		7,110	10,508		7,110		9,147
Long-term accrued income taxes	4,220			4,220
Other long-term liabilities	24,611		11,542	24,611		11,542		25,611
Retained earnings	343,471		282,826	343,471		282,826		298,807	243,152
Noncontrolling interests in subsidiaries	9,430		8,245	9,430		8,245		8,569	8,506
Total stockholders' equity	217,806		212,554	217,806		212,554		218,222	207,200
Condensed Consolidated Statement of Comprehensive Income
Interest expense	284		282	854		1,183
Income before income taxes	21,057		16,846	72,435		62,693
Income tax expense	7,112		4,906	24,479		20,151
Net income, including noncontrolling interests	13,945		11,940	47,956		42,542
Net income, net of noncontrolling interests	13,151		11,123	44,664		39,674
Comprehensive income	15,192		11,687	48,963		43,048
Basic earnings per common share	$ 0.57		$ 0.45	$ 1.89		$ 1.57
Earnings per common share - assuming dilution	$ 0.55		$ 0.44	$ 1.85		$ 1.55
Consolidated Statement of Cash Flows
Net income, including noncontrolling interests	13,945		11,940	47,956		42,542
Deferred income taxes				647		5,219
Other				3,789		1,272
Net cash provided by operating activities				94,773		87,216
Scenario, Adjustment [Member]
Consolidated Statement of Stockholders' Equity
Retained earnings	(4,369)		(3,916)	(4,369)		(3,916)		(4,006)	(3,086)
Noncontrolling interests in subsidiaries	(9,430)		(8,245)	(9,430)		(8,245)		(8,569)	(8,506)
Total stockholders' equity	(13,799)		(12,161)	(13,799)		(12,161)		(12,575)	(11,592)
Condensed Consolidated Balance Sheet
Noncurrent deferred income tax liabilities	(2,678)		(2,400)	(2,678)		(2,400)		(2,455)
Other long-term liabilities	11,657		11,003	11,657		11,003		11,065
Redeemable noncontrolling interests	4,820		3,558	4,820		3,558		3,965
Retained earnings	(4,369)		(3,916)	(4,369)		(3,916)		(4,006)	(3,086)
Noncontrolling interests in subsidiaries	(9,430)		(8,245)	(9,430)		(8,245)		(8,569)	(8,506)
Total stockholders' equity	(13,799)		(12,161)	(13,799)		(12,161)		(12,575)	(11,592)
Condensed Consolidated Statement of Comprehensive Income
Interest expense	194		522	586		1,339
Income before income taxes	(194)		(522)	(586)		(1,339)
Income tax expense	(74)		(199)	(223)		(509)
Net income, including noncontrolling interests	(120)		(323)	(363)		(830)
Net income, net of noncontrolling interests	(120)		(323)	(363)		(830)
Comprehensive income	(120)		(323)	(363)		(830)
Basic earnings per common share	$ (0.01)		$ (0.02)	$ (0.02)		$ (0.03)
Earnings per common share - assuming dilution			$ (0.01)	$ (0.01)		$ (0.03)
Consolidated Statement of Cash Flows
Net income, including noncontrolling interests	(120)		(323)	(363)		(830)
Deferred income taxes				(223)		(509)
Other				586		1,339
As Restated [Member]
Consolidated Statement of Stockholders' Equity
Retained earnings	339,102		278,910	339,102		278,910		294,801	240,066
Total stockholders' equity	204,007		200,393	204,007		200,393		205,647	195,608
Condensed Consolidated Balance Sheet
Noncurrent deferred income tax liabilities	7,830		4,710	7,830		4,710		6,692
Other long-term liabilities	40,488		22,545	40,488		22,545		36,676
Redeemable noncontrolling interests	4,820		3,558	4,820		3,558		3,965
Retained earnings	339,102		278,910	339,102		278,910		294,801	240,066
Total stockholders' equity	204,007		200,393	204,007		200,393		205,647	195,608
Condensed Consolidated Statement of Comprehensive Income
Interest expense	478		804	1,440		2,522
Income before income taxes	20,863		16,324	71,849		61,354
Income tax expense	7,038		4,707	24,256		19,642
Net income, including noncontrolling interests	13,825		11,617	47,593		41,712
Net income, net of noncontrolling interests	13,031		10,800	44,301	[1]	38,844	[1]
Comprehensive income	15,072		11,364	48,600		42,218
Basic earnings per common share	$ 0.56		$ 0.43	$ 1.87		$ 1.54
Earnings per common share - assuming dilution	$ 0.55		$ 0.43	$ 1.84		$ 1.52
Consolidated Statement of Cash Flows
Net income, including noncontrolling interests	13,825		11,617	47,593		41,712
Deferred income taxes				424		4,710
Other				4,375		2,611
Net cash provided by operating activities				94,773		87,216
Reclassifications [Member]
Condensed Consolidated Balance Sheet
Long-term accrued income taxes	(4,220)	[2]		(4,220)	[2]
Other long-term liabilities	$ 4,220	[2]		$ 4,220	[2]

[1] Net income at September 23, 2012 and September 25, 2011 is net of $3,292 and $2,868, respectively, allocable to the redeemable noncontrolling interests for our joint venture arrangements.

[2] Amounts have been reclassified from the originally filed presentation in order to conform to the presentation included in the Form 10-K for the fiscal year ended December 30, 2012, and are not associated with the restatement adjustments.