Derivative Instruments (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)		$ 29.3
Interest Rate Locks, 2005 to 2006 [Member]
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)	(0.4)	(0.4)	(0.4)
Expected effect during next twelve months	(0.3)
Interest Rate Locks, 2006 to 2007 [Member]
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)	3.5	3.8	4.0
Expected effect during next twelve months	3.4
Interest Rate Locks, TRIP Holdings [Member]
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)	17.4
Expected effect during next twelve months	6.0
Interest Rate Swap, TILC Warehouse [Member]
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)		0.5	2.9
Interest Rate Swap TRIP Rail Master Funding Secured Railcar Equipment Notes [Member]
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)	1.1
Expected effect during next twelve months	1.7
Interest Rate Swap, 2008 Debt Issuance [Member]
Interest rate hedges effect on interest expense - increase/(decrease)
Effect on interest expense - increase/(decrease)	19.6	19.7	21.6
Expected effect during next twelve months	$ 17.0