(5) Interest Income and Interest Expense (Details - Interest expense) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	$ 24,901	$ 27,940	$ 78,377	$ 82,933
Securitization Trust Debt [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	21,605	24,208	67,770	72,662
Warehouse Lines Of Credit [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	1,856	2,407	6,294	6,387
Residual interest financing [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	876	956	2,734	2,867
Subordinated renewable notes [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	$ 564	$ 369	$ 1,579	$ 1,017