Derivative Instruments (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest rate swap, Expired, TRIP Holdings warehouse loan
Derivative [Line Items]
Expected effect during next twelve months	$ 4.8
Interest expense | Designated as hedging instrument | Interest rate swap, Expired, 2006 secured railcar equipment notes
Derivative [Line Items]
Expired hedges	(0.3)	$ (0.3)	$ (0.3)
Expected effect during next twelve months	(0.2)
Interest expense | Designated as hedging instrument | Interest rate swap, Expired, Promissory notes
Derivative [Line Items]
Expired hedges	1.2	2.9	3.1
Expected effect during next twelve months	0.0
Interest expense | Designated as hedging instrument | Interest rate swap, Expired, TRIP Holdings warehouse loan
Derivative [Line Items]
Expired hedges	4.9	5.1	6.1
Expected effect during next twelve months	4.8
Interest expense | Designated as hedging instrument | Interest Rate Swap, Open, TRIP Master Funding secured railcar equipment notes
Derivative [Line Items]
Open hedges	1.3	1.5	1.8
Expected effect during next twelve months	0.8
Interest expense | Designated as hedging instrument | Interest Rate Swap, Open, Promissory notes
Derivative [Line Items]
Open hedges	5.3	$ 15.4	$ 15.8
Expected effect during next twelve months	$ 0.0