Variable Interest Entities (Details 1) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	$ 121.9	$ 111.4
Carrying amounts and maximum exposure to loss with respect to VIEs
Maximum Exposure to Loss	121.9	111.4
Investments in affiliates [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	121.3	110.7
Carrying amounts and maximum exposure to loss with respect to VIEs
Maximum Exposure to Loss	121.3	110.7
Other investment [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0.6	0.7
Carrying amounts and maximum exposure to loss with respect to VIEs
Maximum Exposure to Loss	$ 0.6	$ 0.7