Note 13 - Regulatory Capital (Details Textual) $ in Millions	Dec. 31, 2020 USD ($)	Dec. 31, 2019
Amount Available for Dividend Distribution without Affecting Capital Adequacy Requirements	$ 55.7
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	0.0600	0.0600
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0800	0.0800
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	0.0400	0.0400
Capital Conservation Buffer		2.50%
Subsidiaries [Member]
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	0.0600	0.0600
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0800	0.0800
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	0.0400	0.0400