Note 7 - Fair Value Measurements - Level 3 Fair Value Measurements (Details) - Valuation, Market Approach [Member]		Jun. 30, 2020	Dec. 31, 2019
Measurement Input, Discount Rate [Member] | Minimum [Member]
Discount rate	[1]	0.0550	0.0550
Measurement Input, Discount Rate [Member] | Maximum [Member]
Discount rate	[1]	0.0650	0.0650
Measurement Input, Discount Rate [Member] | Weighted Average [Member]
Discount rate	[1]	(0.0594)	(0.0577)
Measurement Input, Cost to Sell [Member] | Maximum [Member]
Level 3 Fair Value Measurements	[2]	0.0554	0.0600
Measurement Input, Cost to Sell [Member] | Weighted Average [Member]
Level 3 Fair Value Measurements	[2]	(0.0046)	(0.0068)
Measurement Input, Discount for Lack of Marketability and Age of Appraisal [Member] | Minimum [Member]
Level 3 Fair Value Measurements	[2]	0.0000	0.0000
Measurement Input, Discount for Lack of Marketability and Age of Appraisal [Member] | Maximum [Member]
Level 3 Fair Value Measurements	[2]	0.1135	0.4517
Measurement Input, Discount for Lack of Marketability and Age of Appraisal [Member] | Weighted Average [Member]
Level 3 Fair Value Measurements	[2]	(0.0095)	(0.0128)

[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.