Leases Future Minimum Lease Rents (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Future Minimum Lease Rents Due [Abstract]
Asset Cost of Leased Property	$ 89.8	$ 94.0
Carrying Amount on Leased Property	69.5	75.1
Contingent Rent Expense on Leases	2.8	3.4	3.9
Minimum Rent Expense on Leases	81.8	87.2	86.6
2012	18.1
2013	18.2
2014	18.2
2015	18.0
2016	17.8
Thereafter	89.7
Total minimum rents receivable	180.0
2012	95.3
2013	95.7
2014	95.8
2015	96.2
2016	95.7
Thereafter	833.5
Total minimum rents receivable	$ 1,312.2