Accounting for Variable Interest Entities - Narrative (Detail) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 26, 2011	Jun. 27, 2010	Jun. 26, 2011	Jun. 27, 2010	Mar. 27, 2011 BIBP Commodities, Inc. [Member]	Jun. 27, 2010 BIBP Commodities, Inc. [Member]	Jun. 27, 2010 BIBP Commodities, Inc. [Member]
Variable Interest Entity [Line Items]
Cost of cheese purchased					$ 25,100,000	$ 37,400,000	$ 76,500,000
Pre-tax income (loss)	19,067,000	21,663,000	45,847,000	48,592,000		2,700,000	6,200,000
Net income, including noncontrolling interests	$ 13,053,000	$ 14,103,000	$ 30,602,000	$ 32,067,000		$ 1,700,000	$ 3,900,000
Earnings per common share - assuming dilution (in dollars per share)	$ 0.47	$ 0.49	$ 1.11	$ 1.11		$ 0.06	$ 0.14
Percent of domestic franchisees who entered into cheese purchasing agreement, minimum	99.00%		99.00%