Note 9 - Loans - Activity in the Allowance for Credit Losses (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Balance		$ 148,772	$ 131,256	$ 136,157	$ 166,538	$ 166,538
Provision/(reversal) for possible credit losses		602	3,000	12,709	(15,710)
Charge-offs		(2,228)	(2,652)	(2,500)	(19,502)
Recoveries		1,671	341	2,451	2,179
Net (charge-offs)/recoveries		(557)	(2,311)	(49)	(17,323)	(17,611)
Balance		148,817	131,945	148,817	131,945	136,157
Charge-offs		(2,228)	(2,652)	(2,500)	(19,502)
Recoveries		1,671	341	2,451	2,179
Commitments to Extend Credit [Member]
Balance		6,136	8,050	7,100	5,880	5,880
Provision/(reversal) for possible credit losses		1,398	50	434	(3,798)
Balance		7,534	8,100	7,534	8,100	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		49,069	40,067	43,394	68,742	68,742
Provision/(reversal) for possible credit losses		1,845	674	7,258	18,891
Charge-offs		(2,091)	(2,649)	(2,362)	(19,499)	(20,051)
Recoveries		1,576	121	2,109	1,545	1,706
Net (charge-offs)/recoveries		(515)	(2,528)	(253)	(17,954)	(18,345)
Balance		50,399	38,213	50,399	38,213	43,394
Charge-offs		(2,091)	(2,649)	(2,362)	(19,499)	(20,051)
Recoveries		1,576	121	2,109	1,545	1,706
Commercial Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		2,804	4,388	3,725	4,802	4,802
Provision/(reversal) for possible credit losses		1,576	329	655	(3,321)
Balance		4,380	4,717	4,380	4,717	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		7,276	6,119	6,302	30,854	30,854
Provision/(reversal) for possible credit losses		(1,065)	149	(97)	(279)
Charge-offs		0	0	0	0	0
Recoveries		0	76	6	76	76
Net (charge-offs)/recoveries		0	76	6	76	76
Balance		6,211	6,344	6,211	6,344	6,302
Charge-offs		0	0	0	0	0
Recoveries		0	76	6	76	76
Real Estate Construction Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		3,306	3,581	3,375	690	690
Provision/(reversal) for possible credit losses		(152)	(396)	(221)	(640)
Balance		3,154	3,185	3,154	3,185	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		68,600	58,026	61,081	49,205	49,205
Provision/(reversal) for possible credit losses		1,362	2,786	8,699	(23,526)
Charge-offs		0	0	0	0	0
Recoveries		88	144	270	284	379
Net (charge-offs)/recoveries		88	144	270	284	379
Balance		70,050	60,956	70,050	60,956	61,081
Charge-offs		0	0	0	0	0
Recoveries		88	144	270	284	379
Commercial Real Estate Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		26	81	0	101	101
Provision/(reversal) for possible credit losses		(26)	117	0	163
Balance		0	198	0	198	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		23,692	27,043	25,379	17,737	17,737
Provision/(reversal) for possible credit losses		(1,612)	(609)	(3,357)	(10,788)
Charge-offs		(58)	(3)	(58)	(3)
Recoveries		7	0	65	274
Net (charge-offs)/recoveries		(51)	(3)	7	271
Balance		22,029	26,431	22,029	26,431	25,379
Charge-offs		(58)	(3)	(58)	(3)
Recoveries		7	0	65	274
Residential Mortgage and Equity Lines Portfolio Segment [Member] | Commitments to Extend Credit [Member]
Balance		0	0	0	284	284
Provision/(reversal) for possible credit losses		0	0	0	0
Balance		0	0	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		135	1	1	0	0
Provision/(reversal) for possible credit losses		72	0	206	(8)
Charge-offs		(79)	0	(80)	0	0
Recoveries		0	0	1	0	(0)
Net (charge-offs)/recoveries		(79)	0	(79)	0	0
Balance		128	1	128	1	1
Charge-offs		(79)	0	(80)	0	0
Recoveries		0	0	1	0	(0)
Installment and Other Loans [Member ] | Commitments to Extend Credit [Member]
Balance		0	0	0	3	3
Provision/(reversal) for possible credit losses		0	0	0	0
Balance		$ 0	$ 0	$ 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.