Derivative Instruments (Details 1) (Designated as hedging instrument, USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 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	(0.3)		(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	2.2		2.4
Expected effect during next twelve months	1.9	[1]		1.9	[1]
Interest expense | Expired hedges | TRIP Holdings warehouse loan
Effect on interest expense - increase/(decrease)
Effect on interest expense	1.3		1.3	3.9		4.8
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		4.0	11.5		12.0
Expected effect during next twelve months	10.3	[1]		10.3	[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	1.2		1.3
Expected effect during next twelve months	$ 1.3	[1]		$ 1.3	[1]

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