Commercial Commitments (Details) (USD $) In Millions, unless otherwise specified	Apr. 30, 2013		Mar. 31, 2013		Dec. 31, 2012
Guarantor Obligations [Line Items]
Total commercial commitments			$ 96.7	[1]	$ 104.5	[1]
Affiliate guarantees [Member]
Guarantor Obligations [Line Items]
Total commercial commitments	42.0	[2]	42.0	[2]	42.0	[2]
Asset residual value guarantees [Member]
Guarantor Obligations [Line Items]
Total commercial commitments			5.1		11.2
Lease payment guarantees [Member]
Guarantor Obligations [Line Items]
Total commercial commitments			39.3		41.0
Performance bonds [Member]
Guarantor Obligations [Line Items]
Total commercial commitments			0.5		0.6
Standby letters of credit [Member]
Guarantor Obligations [Line Items]
Total commercial commitments			$ 9.8		$ 9.7

[1] The carrying values of liabilities on the balance sheet for our commercial commitments were $6.2 million at March 31, 2013 and $6.4 million at December 31, 2012. The expiration dates for our commitments range from 2013–2022. We are not aware of any event that would require us to satisfy any of our commitments.

[2] Excludes one of our guarantees because it does not state a maximum potential future payment and because we believe the likelihood we will be required to perform under that guarantee is remote.