Derivative Instruments (Details 1) (Designated as hedging instrument, USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013
Expired hedges | TRIP Holdings warehouse loan
Effect on interest expense - increase/(decrease)
Expected effect during next twelve months	$ 5.0			$ 5.0
Interest expense | Expired hedges | 2006 secured railcar equipment notes
Effect on interest expense - increase/(decrease)
Effect on interest expense	(0.1)		(0.1)	(0.2)		(0.2)
Expected effect during next twelve months	(0.3)	[1]		(0.3)	[1]
Interest expense | Expired hedges | Promissory notes
Effect on interest expense - increase/(decrease)
Effect on interest expense	0.7		0.8	1.5		1.6
Expected effect during next twelve months	2.6	[1]		2.6	[1]
Interest expense | Expired hedges | TRIP Holdings warehouse loan
Effect on interest expense - increase/(decrease)
Effect on interest expense	1.3		1.5	2.6		3.5
Expected effect during next twelve months	5.0	[1]		5.0	[1]
Interest expense | Open hedges | Promissory notes
Effect on interest expense - increase/(decrease)
Effect on interest expense	3.8		4.1	7.7		8.0
Expected effect during next twelve months	14.2	[1]		14.2	[1]
Interest expense | Open hedges | TRIP Master Funding secured railcar equipment notes
Effect on interest expense - increase/(decrease)
Effect on interest expense	0.4		0.4	0.8		0.9
Expected effect during next twelve months	$ 1.4	[1]		$ 1.4	[1]

[1] Based on the fair value of open hedges as of June 30, 2014