Note 2 - Significant Accounting Policies and Consolidated Financial Statement Components - Components of Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue from contracts with customers		$ 7,312	$ 2,910	$ 11,891	$ 5,636
Credit and Debit Card [Member]
Revenue from contracts with customers	[1]	4,269	1,842	6,891	3,822
Servicing Income [Member]
Revenue from contracts with customers		648	488	1,361	1,092
Service Charges and Other Customer Related Fees [Member]
Revenue from contracts with customers		2,395	580	3,639	722
Credit and Other Investments [Member]
Revenue from contracts with customers		6,998	2,646	11,237	5,135
Credit and Other Investments [Member] | Credit and Debit Card [Member]
Revenue from contracts with customers	[1]	4,269	1,842	6,891	3,822
Credit and Other Investments [Member] | Servicing Income [Member]
Revenue from contracts with customers		349	240	737	624
Credit and Other Investments [Member] | Service Charges and Other Customer Related Fees [Member]
Revenue from contracts with customers		2,380	564	3,609	689
Auto Finance [Member]
Revenue from contracts with customers		314	264	654	501
Auto Finance [Member] | Credit and Debit Card [Member]
Revenue from contracts with customers	[1]	0	0	0	0
Auto Finance [Member] | Servicing Income [Member]
Revenue from contracts with customers		299	248	624	468
Auto Finance [Member] | Service Charges and Other Customer Related Fees [Member]
Revenue from contracts with customers		$ 15	$ 16	$ 30	$ 33

[1] Interchange revenue is presented net of customer reward expense.