Borrowings - Securitizations (Details) - USD ($) $ in Thousands	Jul. 30, 2015	Dec. 31, 2015
Securities Financing Transaction [Line Items]
Total bonds issued		$ 630,800
Total loan amount securitized at inception of the above on-balance sheet term securitization		$ 745,580
2015-B
Securities Financing Transaction [Line Items]
Total bonds issued	$ 630,800
Weighted Average Life	4 years 9 months 26 days
LIBOR | 2015-B
Securities Financing Transaction [Line Items]
Basis spread on variable rate	1.53%