Note 2 - Significant Accounting Policies and Consolidated Financial Statement Components - Summary of Troubled Debt Restructurings (Details) $ in Thousands		12 Months Ended
		Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Amount of TDRs on non-accrual status (in thousands)		$ 55,300	$ 29,200
Point-of-Sale [Member]
Number of TDRs		12,277		10,682
Amount of TDRs on non-accrual status (in thousands)		$ 16,367		$ 14,468
Carrying value of TDRs (in thousands)		$ 10,399		8,864
Number of accounts		3,310	2,279
Loan balance at time of charge off (in thousands)		$ 4,965	$ 3,607
Point-of-Sale [Member] | Performing Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	8,377		6,754
Point-of-Sale [Member] | Nonperforming Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	$ 2,022		$ 2,110
Point-of-Sale [Member] | Extended Maturity [Member]
Number of TDRs		2,753		2,788
Amount of TDRs on non-accrual status (in thousands)		$ 5,068		$ 5,118
Direct-to-Consumer [Member]
Number of TDRs		23,139		14,553
Amount of TDRs on non-accrual status (in thousands)		$ 19,365		$ 13,037
Carrying value of TDRs (in thousands)		$ 11,365		7,312
Number of accounts		4,740	1,985
Loan balance at time of charge off (in thousands)		$ 4,695	$ 2,168
Direct-to-Consumer [Member] | Performing Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	9,945		6,106
Direct-to-Consumer [Member] | Nonperforming Financial Instruments [Member]
Carrying value of TDRs (in thousands)	[1]	$ 1,420		$ 1,206
Direct-to-Consumer [Member] | Extended Maturity [Member]
Number of TDRs		3,878		2,854
Amount of TDRs on non-accrual status (in thousands)		$ 3,967		$ 3,104

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