Railcar Leasing and Management Services Group (Details 2) (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
Wholly-owned subsidiaries
Future contractual minimum rental revenues on leases
Remaining nine months of 2013	228.6
2014	252.7
2015	207.1
2016	160.7
2017	116.5
Thereafter	246.1
Total	1,211.7
Partially-owned subsidiary
Future contractual minimum rental revenues on leases
Remaining nine months of 2013	74.4
2014	77.4
2015	64.5
2016	53.1
2017	38.8
Thereafter	48.8
Total	$ 357.0