(3) Finance Receivables (Details - Amortized Cost Basis) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	$ 491,307	$ 895,566
Vintage Pool 2012 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	608	2,432
Vintage Pool 2013 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	4,483	15,489
Vintage Pool 2014 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	23,115	61,290
Vintage Pool 2015 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	78,457	162,242
Vintage Pool 2016 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	163,677	292,360
Vintage Pool 2017 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	$ 220,967	$ 361,753