Note 6 - Fair Value Measurements and Fair Value of Financial Instruments - Significant Unobservable Inputs for Assets Measured on Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] $ in Thousands	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Commercial Portfolio Segment [Member]
Collateral dependent loans, fair value	$ 14,657	$ 13,399
Commercial Real Estate Portfolio Segment [Member]
Collateral dependent loans, fair value	15,630	20,185
Residential Portfolio Segment [Member]
Collateral dependent loans, fair value	1,365	2,794
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member]
Collateral dependent loans, fair value	14,657	13,399
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Valuation, Market Approach [Member] | Average Transfer Price as Price to Unpaid Principal Balance [Member]
Collateral dependent loans, fair value	$ 14,006	$ 12,193
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Valuation, Market Approach [Member] | Average Transfer Price as Price to Unpaid Principal Balance [Member] | Minimum [Member]
Collateral dependent loans, rate	0.58	0.48
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Valuation, Market Approach [Member] | Average Transfer Price as Price to Unpaid Principal Balance [Member] | Maximum [Member]
Collateral dependent loans, rate	0.88	0.73
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Valuation, Market Approach [Member] | Average Transfer Price as Price to Unpaid Principal Balance [Member] | Weighted Average [Member]
Collateral dependent loans, rate	0.60	0.49
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member]
Collateral dependent loans, fair value	$ 651	$ 1,206
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Minimum [Member]
Collateral dependent loans, rate	(0.10)	(0.10)
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Maximum [Member]
Collateral dependent loans, rate	0.35	0.35
Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Weighted Average [Member]
Collateral dependent loans, rate	0.08	0.06
Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Portfolio Segment [Member]
Collateral dependent loans, fair value	$ 15,630	$ 20,185
Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member]
Collateral dependent loans, fair value	$ 15,630	$ 20,185
Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Minimum [Member]
Collateral dependent loans, rate	(0.25)	(0.20)
Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Maximum [Member]
Collateral dependent loans, rate	0.10	0.15
Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Weighted Average [Member]
Collateral dependent loans, rate	(0.14)	(0.06)
Fair Value, Inputs, Level 3 [Member] | Residential Portfolio Segment [Member]
Collateral dependent loans, fair value	$ 1,365	$ 2,794
Fair Value, Inputs, Level 3 [Member] | Residential Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member]
Collateral dependent loans, fair value	$ 1,365	$ 2,794
Fair Value, Inputs, Level 3 [Member] | Residential Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Minimum [Member]
Collateral dependent loans, rate	0.21	(0.15)
Fair Value, Inputs, Level 3 [Member] | Residential Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Maximum [Member]
Collateral dependent loans, rate	0.39	0.39
Fair Value, Inputs, Level 3 [Member] | Residential Portfolio Segment [Member] | Appraisals of Collateral Value [Member] | Measurement Input, Comparability Adjustment [Member] | Weighted Average [Member]
Collateral dependent loans, rate	0.22	0.05