Note 2 - Accounting Policies - Impact of Adoption of ASU 2016-13 (Details) - USD ($) $ in Thousands	Jun. 30, 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	$ 16	0	$ 0
Allowance for credit losses for unfunded commitments		2,160
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	$ 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