Note 6 - Fair Values of Assets and Liabilities - Summary of Other Relevant Data (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Loans, interest and fees receivable, at fair value	$ 417,098	$ 4,386
Loans and Fees Receivable at Fair Value [Member]
Aggregate unpaid gross balance of loans, interest and fees receivable that are reported at fair value	630	713
Aggregate unpaid principal balance included within loans, interest and fees receivable that are reported at fair value	589	644
Loans, interest and fees receivable, at fair value	540	466
Aggregate fair value of receivables carried at fair value that are 90 days or more past due (which also coincides with finance charge and fee non-accrual policies)	1	1
Unpaid principal balance of receivables within loans, interest and fees receivable that are reported at fair value and are 90 days or more past due (which also coincides with finance charge and fee non-accrual policies) over the fair value of such loans, interest and fees receivable	4	28
Structured Financing Notes Payable [Member]
Aggregate unpaid principal balance included within loans, interest and fees receivable that are reported at fair value	101,314	101,314
Aggregate fair value of notes payable	2,919	3,920
Loans and Fees Receivable Pledged as Collateral, Fair Value [Member]
Aggregate unpaid gross balance of loans, interest and fees receivable that are reported at fair value	515,434	5,691
Aggregate unpaid principal balance included within loans, interest and fees receivable that are reported at fair value	487,779	5,280
Loans, interest and fees receivable, at fair value	416,558	3,920
Aggregate fair value of receivables carried at fair value that are 90 days or more past due (which also coincides with finance charge and fee non-accrual policies)	1,847	8
Unpaid principal balance of receivables within loans, interest and fees receivable that are reported at fair value and are 90 days or more past due (which also coincides with finance charge and fee non-accrual policies) over the fair value of such loans, interest and fees receivable	$ 12,972	$ 185