Note 15 - Fair Value Measurements - Level 3 Fair Value Measurements (Details)		Dec. 31, 2019	Dec. 31, 2018
Measurement Input, Discount Rate [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Discount rate		0.055	0.055
Measurement Input, Discount Rate [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Discount rate		0.065	0.0725
Measurement Input, Discount Rate [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Discount rate		0.0577	0.0605
Measurement Input, Cost to Sell [Member] | Minimum [Member] | Discounted Appraised Value [Member]
Level 3 Fair Value Measurements	[1]	0	0
Measurement Input, Cost to Sell [Member] | Maximum [Member] | Discounted Appraised Value [Member]
Level 3 Fair Value Measurements		0.06	0.06
Measurement Input, Cost to Sell [Member] | Weighted Average [Member] | Discounted Appraised Value [Member]
Level 3 Fair Value Measurements		0.0068	0.0012
Measurement Input, Discount for Lack of Marketability and Age of Appraisal [Member] | Minimum [Member] | Discounted Appraised Value [Member]
Level 3 Fair Value Measurements		0	0
Measurement Input, Discount for Lack of Marketability and Age of Appraisal [Member] | Maximum [Member] | Discounted Appraised Value [Member]
Level 3 Fair Value Measurements		0.4517	0.5005
Measurement Input, Discount for Lack of Marketability and Age of Appraisal [Member] | Weighted Average [Member] | Discounted Appraised Value [Member]
Level 3 Fair Value Measurements		0.0128	0.0145

[1] The Company markets OREO both independently and with local realtors. Properties marketed by realtors are discounted by selling costs. Properties that the Company markets independently are not discounted by selling costs.