Note 13 - Fair Value Measurements - Quantitative Information About Level 3 Fair Value Measurements (Details) - Fair Value, Inputs, Level 3 [Member]	Mar. 31, 2021	[1]
Valuation Technique, Discounted Appraisal Value [Member] | Measurement Input, Cost to Sell [Member]
Impaired loans	0.0800
Other real estate owned, net	0.0800
Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member] | Minimum [Member]
Impaired loans	0.0413
Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member] | Maximum [Member]
Impaired loans	0.072
Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member] | Weighted Average [Member]
Impaired loans	0.0520

[1] Unobservable inputs were weighted by the relative fair value of the impaired loans.