Railcar Leasing and Management Services Group (Details 4) (Leasing Group [Member], USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Future operating lease obligations related to these leases
Remaining six months of 2012	$ 188.5
2013	315.4
2014	241.8
2015	190.5
2016	147.8
Thereafter	283.8
Total	1,367.8
Future operating lease obligations other than leases with trusts [Member]
Future operating lease obligations related to these leases
Remaining six months of 2012	4.5
2013	8.9
2014	8.8
2015	8.8
2016	8.6
Thereafter	38.0
Total	77.6
Future contractual minimum rental revenues from other than leases with trusts [Member]
Future operating lease obligations related to these leases
Remaining six months of 2012	5.3
2013	10.2
2014	9.3
2015	6.0
2016	5.0
Thereafter	7.6
Total	$ 43.4