Leases (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Capital Leases
2012, Capital Leases	$ 3.8
2013, Capital Leases	3.1
2014, Capital Leases	3.1
2015, Capital Leases	3.1
2016, Capital Leases	2.7
Years thereafter, Capital Leases	1.1
Capital Leases, Future Minimum Payments Due, Total	16.9
Less: amounts representing interest	(2.6)
Present value of future minimum capital lease payments	14.3	41.9
Recourse Operating Leases [Member]
Operating Leases
2012, Operating Lease	112.3
2013, Operating Lease	104.6
2014, Operating Lease	108.4
2015, Operating Lease	126.0
2016, Operating Lease	88.5
Years thereafter, Operating Leases	427.0
Total, Operating Leases	966.8
Nonrecourse Operating Leases [Member]
Operating Leases
2012, Operating Lease	27.9
2013, Operating Lease	28.3
2014, Operating Lease	27.7
2015, Operating Lease	26.3
2016, Operating Lease	22.1
Years thereafter, Operating Leases	98.9
Total, Operating Leases	$ 231.2