Impairment Of Long-Lived Assets And Other Lease Charges (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Impaired Long-Lived Assets Held and Used [Line Items]
Other lease charges	$ 1.0	$ 1.6
Other lease charges, number of restaurants		4
Asset impairment charges, number of restaurants	9	19
Underperforming Restaurants [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges	2.6	2.8	1.0
Previously Impaired [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges	1.1	0.9
Initial Impairments [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges	$ 1.4	$ 1.9