Note 9 - Loans - Activity in the Allowance for Credit Losses (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Balance		$ 136,157	$ 166,538	$ 166,538
Provision/(reversal) for possible credit losses		9,339	(12,109)
Charge-offs		(221)	(9,138)
Recoveries		511	1,379
Net (charge-offs)/recoveries		290
Balance		145,786	145,110	136,157
Charge-offs		(221)	(9,138)
Recoveries		511	1,379
Net (charge-offs)/recoveries		290	(7,759)	(17,611)
Commitments to Extend Credit [Member]
Balance		7,100	5,880	5,880
Provision/(reversal) for possible credit losses		(696)	(1,449)
Balance		6,404	10,449	7,100
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance			(1,560)	(1,560)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
Balance	[1]		6,018	6,018
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			164,978	164,978
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commitments to Extend Credit [Member]
Balance			11,898	11,898
Commercial Portfolio Segment [Member]
Balance		43,394	68,742	68,742
Provision/(reversal) for possible credit losses		1,206	12,627
Charge-offs		(221)	(9,138)	(20,051)
Recoveries		359	1,269	1,706
Net (charge-offs)/recoveries		138
Balance		44,738	42,034	43,394
Charge-offs		(221)	(9,138)	(20,051)
Recoveries		359	1,269	1,706
Net (charge-offs)/recoveries		138	(7,869)	(18,345)
Commercial Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		3,725	4,802	4,802
Provision/(reversal) for possible credit losses		(548)	125
Balance		3,177	8,163	3,725
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance			(31,466)	(31,466)
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
Balance	[1]		3,236	3,236
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			37,276	37,276
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commitments to Extend Credit [Member]
Balance			8,038	8,038
Real Estate Construction Portfolio Segment [Member]
Balance		6,302	30,854	30,854
Provision/(reversal) for possible credit losses		1,128	446
Charge-offs		0	0	0
Recoveries		6	0	76
Net (charge-offs)/recoveries		6
Balance		7,436	6,993	6,302
Charge-offs		0	0	0
Recoveries		6	0	76
Net (charge-offs)/recoveries		6	0	76
Real Estate Construction Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		3,375	690	690
Provision/(reversal) for possible credit losses		(148)	(1,574)
Balance		3,227	2,251	3,375
Real Estate Construction Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance			(24,307)	(24,307)
Real Estate Construction Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
Balance	[1]		3,135	3,135
Real Estate Construction Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			6,547	6,547
Real Estate Construction Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commitments to Extend Credit [Member]
Balance			3,825	3,825
Commercial Real Estate Portfolio Segment [Member]
Balance		61,081	49,205	49,205
Provision/(reversal) for possible credit losses		2,702	(18,851)
Charge-offs		0	0	0
Recoveries		95	0
Net (charge-offs)/recoveries		95
Balance		63,878	65,347	61,081
Charge-offs		0	0	0
Recoveries		95	0
Net (charge-offs)/recoveries		95	0	379
Commercial Real Estate Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		0	101	101
Provision/(reversal) for possible credit losses		0	0
Balance		0	35	0
Commercial Real Estate Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance			34,993	34,993
Commercial Real Estate Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
Balance	[1]		(66)	(66)
Commercial Real Estate Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			84,198	84,198
Commercial Real Estate Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commitments to Extend Credit [Member]
Balance			35	35
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Balance		25,379	17,737	17,737
Provision/(reversal) for possible credit losses		4,200	(6,325)
Charge-offs		0	0
Recoveries		51	110
Net (charge-offs)/recoveries		51
Balance		29,630	30,733	25,379
Charge-offs		0	0
Recoveries		51	110
Net (charge-offs)/recoveries			110
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		0	284	284
Provision/(reversal) for possible credit losses		0	0
Balance		0	0	0
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance			19,211	19,211
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
Balance	[1]		(284)	(284)
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			36,948	36,948
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commitments to Extend Credit [Member]
Balance			0	0
Installment and Other Loans [Member ]
Balance		1	0	0
Provision/(reversal) for possible credit losses		103	(6)
Charge-offs		0	0	0
Recoveries		(0)	0	(0)
Net (charge-offs)/recoveries		0
Balance		104	3	1
Charge-offs		0	0	0
Recoveries		(0)	0	(0)
Net (charge-offs)/recoveries		0	0	0
Installment and Other Loans [Member ] | Commitments to Extend Credit [Member]
Balance		0	3	3
Provision/(reversal) for possible credit losses		0	0
Balance		$ 0	0	0
Installment and Other Loans [Member ] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member]
Balance			9	9
Installment and Other Loans [Member ] | Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
Balance	[1]		(3)	(3)
Installment and Other Loans [Member ] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Balance			9	9
Installment and Other Loans [Member ] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Commitments to Extend Credit [Member]
Balance			$ 0	$ 0

[1] Balance sheet amounts previously reported for the impact of the initial adoption of CECL on January 1, 2021 have been corrected. The correction decreased the allowance for loan losses by $2.2 million and increased the allowance for unfunded credit commitments by $5.5 million.