5. Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Total interest expense	$ 23,236	$ 19,727	$ 45,324	$ 37,548
Securitization Trust Debt [Member]
Total interest expense	20,537	16,875	40,617	31,639
WarehouseLinesOfCreditMember
Total interest expense	2,379	2,244	4,087	4,666
Residual interest financing [Member]
Total interest expense	0	245	0	516
Subordinated renewable notes [Member]
Total interest expense	$ 320	$ 363	$ 620	$ 727