Note 4 - Loan Receivables and Allowance for Loan and Lease Losses - Non-accrual Loans (Details) - Business Activities Loans [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Non-accruing loans	$ 20,005	$ 18,049
Performing Financial Instruments [Member]
Performing (accruing) loans, past due	8,486	4,441
Performing (accruing) loans, current	701,689	789,674
Commercial Real Estate Portfolio Segment [Member]
Non-accruing loans	14,534	11,961
Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	363
Performing (accruing) loans, current	267,481	302,453
Residential Portfolio Segment [Member]
Non-accruing loans	3,854	3,228
Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	839	658
Performing (accruing) loans, current	149,158	171,603
Commercial Portfolio Segment [Member]
Non-accruing loans	700	2,094
Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	4,925	956
Performing (accruing) loans, current	138,672	170,825
Consumer Portfolio Segment [Member]
Non-accruing loans	917	766
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	8	2,827
Performing (accruing) loans, current	66,710	82,341
Non-Accrual Loans [Member]
Performing (accruing) loans, past due	9,420	5,381
Performing (accruing) loans, current	10,585	12,668
Substandard [Member]
Non-accruing loans	20,005
Substandard [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	1,079
Performing (accruing) loans, current	38,780
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-accruing loans	14,534	11,961
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	363
Performing (accruing) loans, current	10,999	6,086
Substandard [Member] | Residential Portfolio Segment [Member]
Non-accruing loans	3,854	3,228
Substandard [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Performing (accruing) loans, current		1,700
Substandard [Member] | Commercial Portfolio Segment [Member]
Non-accruing loans	700	2,094
Substandard [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	716
Performing (accruing) loans, current	27,660	7,942
Substandard [Member] | Consumer Portfolio Segment [Member]
Non-accruing loans	917	766
Substandard [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Performing (accruing) loans, current	121
Substandard [Member] | Non-Accrual Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Performing (accruing) loans, past due	5,723	1,636
Performing (accruing) loans, current	8,811	10,325
Substandard [Member] | Non-Accrual Loans [Member] | Residential Portfolio Segment [Member]
Performing (accruing) loans, past due	2,884	1,872
Performing (accruing) loans, current	970	1,356
Substandard [Member] | Non-Accrual Loans [Member] | Commercial Portfolio Segment [Member]
Performing (accruing) loans, past due	700	1,724
Performing (accruing) loans, current	0	370
Non-accruing loans		2,094
Substandard [Member] | Non-Accrual Loans [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due		0
Substandard [Member] | Non-Accrual Loans [Member] | Consumer Portfolio Segment [Member]
Performing (accruing) loans, past due	113	149
Performing (accruing) loans, current	804	617
Financial Asset, 30 to 59 Days Past Due [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	1,436	4,069
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	354
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	478	658
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	603	606
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	1	2,805
Financial Asset, 30 to 59 Days Past Due [Member] | Non-Accrual Loans [Member]
Performing (accruing) loans, past due	22	0
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	957
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	354
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	603
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Residential Portfolio Segment [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Commercial Portfolio Segment [Member]
Performing (accruing) loans, past due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Consumer Portfolio Segment [Member]
Performing (accruing) loans, past due	22	0
Financial Asset, 60 to 89 Days Past Due [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	7,034	353
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	361
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	4,322	350
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due		3
Financial Asset, 60 to 89 Days Past Due [Member] | Non-Accrual Loans [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	113
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	113
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Residential Portfolio Segment [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Commercial Portfolio Segment [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Consumer Portfolio Segment [Member]
Performing (accruing) loans, past due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	16	19
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	9
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	7	19
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Non-Accrual Loans [Member]
Performing (accruing) loans, past due	9,398	5,381
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	9
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due	9
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Commercial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Performing (accruing) loans, past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Performing (accruing) loans, past due	5,723	1,636
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Residential Portfolio Segment [Member]
Performing (accruing) loans, past due	2,884	1,872
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Commercial Portfolio Segment [Member]
Performing (accruing) loans, past due	700	1,724
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Substandard [Member] | Non-Accrual Loans [Member] | Consumer Portfolio Segment [Member]
Performing (accruing) loans, past due	$ 91	$ 149