Variable Interest Entities (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	$ 106.9	$ 151.6
Maximum Exposure to Loss	106.9	151.6
Investments in affiliates [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	69.0	72.2
Maximum Exposure to Loss	69.0	72.2
Leveraged leases [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	37.0	78.5
Maximum Exposure to Loss	37.0	78.5
Other investment [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	0.9	0.9
Maximum Exposure to Loss	$ 0.9	$ 0.9