Derivatives (Details) (USD $) In Thousands, unless otherwise specified					9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Interest rate derivatives designated as cash flow hedges Securitization No. 1 London Interbank Offered Rate (LIBOR)	Sep. 30, 2014 Not Designated as Hedging Instrument Securitization No. 1 London Interbank Offered Rate (LIBOR)	Sep. 30, 2014 Cash Flow Hedging Interest Rate Contract Interest rate derivatives designated as cash flow hedges Securitization No. 2	Sep. 30, 2014 Cash Flow Hedging Interest Rate Contract Interest rate derivatives designated as cash flow hedges Securitization No. 2 Minimum	Sep. 30, 2014 Cash Flow Hedging Interest Rate Contract Interest rate derivatives designated as cash flow hedges Securitization No. 2 Maximum	Sep. 30, 2014 Cash Flow Hedging Interest Rate Contract Interest rate derivatives designated as cash flow hedges Derivative Liabilities Securitization No. 2
Derivatives, Fair Value [Line Items]
Current Notional Amount					$ 389,484
Future Maximum Notional Amount					389,484
Floating Rate					1M LIBOR
Fixed Rate						1.26%	1.28%
Derivative liabilities	$ 3,090	$ 39,992						$ 3,090
Derivative, Basis Spread on Variable Rate