(2) Finance Receivables (Details - Amortized Cost Basis) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	$ 668,449	$ 895,566
Vintage Pool 2012 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	1,312	2,432
Vintage Pool 2013 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	9,057	15,489
Vintage Pool 2014 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	41,225	61,290
Vintage Pool 2015 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	122,363	162,242
Vintage Pool 2016 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	228,234	292,360
Vintage Pool 2017 [Member]
Financing Receivable, Nonaccrual [Line Items]
Amortized cost basis	$ 266,258	$ 361,753