Note 2 - Significant Accounting Policies and Consolidated Financial Statement Components - Summary of Troubled Debt Restructurings (Details) $ in Thousands		12 Months Ended
		Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Point-of-Sale [Member]
Number of TDRs		13,990		12,394
Amount of TDRs on non-accrual status (in thousands)		$ 16,245		$ 14,537
Carrying value of TDRs (in thousands)		$ 10,720		9,583
Number of accounts		2,502	3,820
Loan balance at time of charge off (in thousands)		$ 3,420	$ 5,333
Point-of-Sale [Member] | Performing Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	8,643		7,420
Point-of-Sale [Member] | Nonperforming Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	$ 2,077		$ 2,163
Point-of-Sale [Member] | Extended Maturity [Member]
Number of TDRs		1,222		2,788
Amount of TDRs on non-accrual status (in thousands)		$ 1,779		$ 4,662
Direct-to-Consumer [Member]
Number of TDRs		35,026		37,784
Amount of TDRs on non-accrual status (in thousands)		$ 23,060		$ 26,989
Carrying value of TDRs (in thousands)		$ 14,649		14,287
Number of accounts		5,624	7,986
Loan balance at time of charge off (in thousands)		$ 4,489	$ 7,055
Direct-to-Consumer [Member] | Performing Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	12,933		11,855
Direct-to-Consumer [Member] | Nonperforming Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	$ 1,716		$ 2,432
Direct-to-Consumer [Member] | Extended Maturity [Member]
Number of TDRs		3,032		7,846
Amount of TDRs on non-accrual status (in thousands)		$ 2,295		$ 6,890

[1] "TDRs - Performing" include accounts that are current on all amounts owed, while "TDRs - Nonperforming" include all accounts with past due amounts owed.