Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 27, 2011 Supplier Year Restaurant	Dec. 28, 2010
Commitments and Contingencies
Estimated cost to complete capital project commitments (in dollars)	$ 77.6	$ 52.8
Number of suppliers providing most of the company's beef	3
Minimum age specified in age discrimination allegation against entity (in years)	40
Number of restaurants operated in Massachusetts	9