Basis of Presentation (Details)	3 Months Ended
	Mar. 26, 2013 restaurant	Mar. 27, 2012 restaurant
Basis of Presentation
Threshold percentage of ownership for consolidated subsidiaries	50.00%	50.00%
Percentage of ownership interest in unconsolidated affiliate franchise restaurants, low end of range	5.00%	5.00%
Percentage of ownership interest in unconsolidated affiliate franchise restaurants, high end of range	10.00%	10.00%
Number of unconsolidated affiliate franchise restaurants	23	22