Railcar Leasing and Management Services Group (Details Textual) (USD $) In Millions, unless otherwise specified	6 Months Ended		1 Months Ended	6 Months Ended		1 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jul. 31, 2011 TRIP Holdings [Member]	Jun. 30, 2012 Leasing Group [Member]	Jun. 30, 2012 Leasing Group [Member] Wholly Owned Subsidiaries [Member]	Jul. 31, 2011 Leasing Group [Member] TRIP Holdings [Member]
Railcar Leasing and Management Services Group (Textual) [Abstract]
Period of lease contracts with third parties, range minimum (in years)				1 year
Period of lease contracts with third parties, range maximum (in years)				20 years
Net book value of equipment pledged as collateral for leasing group debt					$ 2,430.8
Equipment net pledged as collateral for securing capital lease obligations					1,134.0
New debt issued to repay outstanding borrowings of TRIP Warehouse Loan			1,032.0			1,032.0
Period of railcars leased from the Trusts under operating leases					22 years
Total assets	6,197.5	6,121.0			211.2
Cash					83.3
Railcars					95.2
Railcar Leasing and Management Services Group (Additional Textual) [Abstract]
Operating lease obligations guaranteed	28.2
Net book value of equipment securing capital lease obligations	50.3
Net book value of unpledged equipment	$ 621.9