Borrowings - Securitizations (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Jul. 31, 2015
Securities Financing Transaction [Line Items]
Total bonds issued	$ 630,800
Weighted Average Life	4 years 8 months 55 days
Total loan amount securitized in 2015	$ 745,580
2015-B
Securities Financing Transaction [Line Items]
Total bonds issued		$ 630,800
LIBOR | 2015-B
Securities Financing Transaction [Line Items]
Basis spread on variable rate		1.53%