Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified			6 Months Ended				6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Joint Ventures	Jun. 30, 2013 Property Lease Guarantee Joint Venture One option	Jun. 30, 2013 Financial Guarantee Joint Venture Two	Dec. 31, 2012 Financial Guarantee Joint Venture Two	Jun. 30, 2013 Performance Guarantee	Jun. 30, 2013 Pending Litigation
Loss Contingencies [Line Items]
Letters of credit outstanding	$ 7.2	$ 7.2
Maximum range of possible loss contingency								10.0
Accrued loss contingency	7.9
Equity method investments ownership percentage			50.00%	50.00%	50.00%
Guarantee obligations, maximum exposure, percent				50.00%
Lease, initial term				10 years 7 months
Number of options for lease extension				2
Period available under options for lease extension				5 years
Base rent for the initial term per year				4.8
Maximum guarantee					3.0		5.0
Mortgage loan					32.0
Total borrowings on the loan					28.7	29.1
Guarantee obligation	$ 0.8	$ 0.8			$ 1.5	$ 1.5	$ 0.8
Franchise agreement, period							20 years
Shareholder agreements, portion of directors entitled to elect, percent			0.5
Partnership agreements, voting managing interest, percent			50.00%