(5) Interest Income and Interest Expense (Details - Interest expense) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	$ 26,485	$ 27,703	$ 53,476	$ 54,993
Securitization Trust Debt [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	22,367	24,466	46,165	48,454
Warehouse Lines Of Credit [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	2,675	1,960	4,437	3,980
Residual interest financing [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	920	955	1,857	1,911
Subordinated renewable notes [Member]
Obligation with Joint and Several Liability Arrangement [Line Items]
Total interest expense	$ 523	$ 322	$ 1,017	$ 648