Note 1 - Business and Accounting Policies - Impact of Adoption of ASU 2016-13 (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Allowance for credit losses (loans)			$ 19,484
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Ending Balance	$ 7	$ 9	0	$ 0
Allowance for credit losses for unfunded commitments			2,160
Cumulative Effect, Period of Adoption, Adjustment [Member]
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Ending Balance		0		16
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			2,017
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Ending Balance			16
Allowance for credit losses for unfunded commitments			(2,107)
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			21,501
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Ending Balance		$ 9	16	$ 16
Allowance for credit losses for unfunded commitments			53
Commercial Portfolio Segment [Member]
Allowance for credit losses (loans)			4,959
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			3,385
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			8,344
Commercial Real Estate Portfolio Segment [Member]
Allowance for credit losses (loans)			4,064
Commercial Real Estate Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			618
Commercial Real Estate Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			4,682
Construction Portfolio Segment [Member]
Allowance for credit losses (loans)			109
Construction Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			(31)
Construction Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			78
Residential Portfolio Segment [Member]
Allowance for credit losses (loans)			206
Residential Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			(132)
Residential Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			74
Consumer Portfolio Segment [Member]
Allowance for credit losses (loans)			6,445
Consumer Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			1,878
Consumer Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			8,323
Unallocated Financing Receivables [Member]
Allowance for credit losses (loans)			3,701
Unallocated Financing Receivables [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses (loans)			(3,701)
Unallocated Financing Receivables [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Allowance for credit losses (loans)			$ 0