Variable Interest Entities (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	$ 151.6	$ 136.0
Maximum Exposure to Loss	151.6	136.0
Investments in affiliates [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	72.2	60.9
Maximum Exposure to Loss	72.2	60.9
Leveraged leases [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	78.5	74.1
Maximum Exposure to Loss	78.5	74.1
Other investment [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	0.9	1.0
Maximum Exposure to Loss	$ 0.9	$ 1.0