5. Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Total interest expense	$ 23,317	$ 20,893	$ 68,641	$ 58,442
Securitization Trust Debt [Member]
Total interest expense	20,973	18,228	61,589	49,867
WarehouseLinesOfCreditMember
Total interest expense	1,994	2,111	6,081	6,777
Residual interest financing [Member]
Total interest expense	0	227	0	744
Subordinated renewable notes [Member]
Total interest expense	$ 350	$ 327	$ 971	$ 1,054