Railcar Leasing and Management Services Group (Details 4) (Leasing Group, USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Future contractual minimum rental revenues on leases
Remaining nine months of 2013	$ 303.0
2014	330.1
2015	271.6
2016	213.8
2017	155.3
Thereafter	294.9
Total	1,568.7
Future operating lease obligations of railcars other than those owned by the Trusts
Future contractual minimum rental obligations on leases
Remaining nine months of 2013	9.7
2014	12.8
2015	12.8
2016	12.7
2017	12.1
Thereafter	50.3
Total	110.4
Future contractual minimum rental revenues of railcars other than those owned by the Trusts
Future contractual minimum rental revenues on leases
Remaining nine months of 2013	12.4
2014	16.0
2015	12.3
2016	11.4
2017	8.8
Thereafter	14.2
Total	$ 75.1