Note 6 - Fair Value Measurements - Level 3 Fair Value Measurements (Details) - Valuation, Market Approach [Member]	Dec. 31, 2020
Measurement Input, Discount Rate [Member] | Minimum [Member]
Impaired loans	0.0550	[1]
OREO	0.0000	[2]
Measurement Input, Discount Rate [Member] | Maximum [Member]
Impaired loans	0.0650	[1]
OREO	0.0766	[2]
Measurement Input, Discount Rate [Member] | Weighted Average [Member]
Impaired loans	0.0578	[1]
Measurement Input, Cost to Sell [Member] | Minimum [Member]
OREO	0.0400	[2]
Measurement Input, Cost to Sell [Member] | Maximum [Member]
OREO	0.0923	[2]

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

[2] Discounts were weighted by the relative appraised value of the OREO properties.