Note 2 - Investment Securities (Details Textual) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Restricted Investments	$ 2,209		$ 2,209		$ 2,416
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	32		32
Percentage of Debt Securities with Unrealized Losses Depreciated	1.80%		1.80%
Proceeds from Sale of Debt Securities, Available-for-sale	$ 8,620	$ 2,940	$ 8,619	$ 10,739
Proceeds from Calls of Debt Securities, Available-for-sale			500	$ 1,290
Deposit Liabilities, Collateral Issued, Financial Instruments	$ 23,200		$ 23,200		$ 14,100