Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 25, 2012 item	Dec. 27, 2011
Commitments and Contingencies
Estimated cost to complete capital project commitments (in dollars)	$ 73.2	$ 58.6
Ownership percentage	5.00%
Number of suppliers providing most of the company's beef	4
Minimum age specified in age discrimination allegation against entity	40 years
Number of motions filed by the entity in response to a complaint filed by the EEOC	2
Number of motions filed by the entity to dismiss a case filed by the EEOC	1
Number of motions filed by the entity to transfer a case filed by the EEOC	1
Settlement expense	$ 5.0