(9) Fair Value Measurements (Details - Level 3 Fair Value Measurements) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Finance receivables measured at fair value	$ 1,533,723	$ 1,523,726	$ 1,559,697	$ 1,444,038
Portion at Fair Value Measurement [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Finance receivables measured at fair value	1,533,723	1,523,726
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Finance receivables measured at fair value	$ 1,533,723	$ 1,523,726
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Measurement Input, Discount Rate [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Inputs	11.00%	10.40%
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Measurement Input, Discount Rate [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Inputs	11.30%	11.10%
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Measurement Input Cumulative Net Lossese [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Inputs	15.40%	15.30%
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Measurement Input Cumulative Net Lossese [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unobservable Inputs	18.40%	18.40%