Variable Interest Entities (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	$ 110.9	$ 111.4
Maximum Exposure to Loss	110.9	111.4
Investments in affiliates [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	110.2	110.7
Maximum Exposure to Loss	110.2	110.7
Other investment [Member]
Carrying amounts and maximum exposure to loss with respect to VIEs
Net Carrying Amount	0.7	0.7
Maximum Exposure to Loss	$ 0.7	$ 0.7