Note 5 - Loans and the Allowance for Credit Losses - Loans by Origination and Risk Designation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Originated Current Fiscal Year	$ 511,688	$ 444,378
Originated One Year Prior	443,185	1,873,427
Originated Two Years Prior	1,724,765	1,891,130
Originated Three Years Prior	1,782,673	419,300
Originated Four Years Prior	397,679	389,442
Originated Five or More Years Prior	1,685,185	1,497,749
Revolving Loans	1,735,307	1,836,415
Gross loans	8,280,482	8,351,841
Gross write-off, current year	0	54
Gross write-off, one year prior	0	3,397
Gross write-off, two years prior	1,003	0
Gross write-off, three years prior	49	0
Gross write-off, four years prior	0	280
Gross write-off, five years prior	10,732	13,236
Gross write-off, revolving	1,918	82
Gross write-off	13,702	17,049	$ 5,443
Pass [Member]
Originated Current Fiscal Year	509,780	444,128
Originated One Year Prior	440,166	1,862,368
Originated Two Years Prior	1,660,146	1,888,446
Originated Three Years Prior	1,778,072	419,299
Originated Four Years Prior	393,127	387,013
Originated Five or More Years Prior	1,566,356	1,435,499
Revolving Loans	1,711,061	1,802,411
Gross loans	8,058,708	8,239,164
Special Mention [Member]
Originated Current Fiscal Year	1,908	0
Originated One Year Prior	0	10,620
Originated Two Years Prior	56,459	0
Originated Three Years Prior	2,538	0
Originated Four Years Prior	1,643	562
Originated Five or More Years Prior	66,563	28,270
Revolving Loans	20,264	14,716
Gross loans	149,375	54,168
Substandard [Member]
Originated Current Fiscal Year	0	250
Originated One Year Prior	3,019	439
Originated Two Years Prior	8,160	2,684
Originated Three Years Prior	2,063	1
Originated Four Years Prior	2,909	1,867
Originated Five or More Years Prior	52,266	33,980
Revolving Loans	3,982	19,288
Gross loans	72,399	58,509
Doubtful [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Commercial Portfolio Segment [Member]
Originated Current Fiscal Year	69,206	178,832
Originated One Year Prior	160,086	263,210
Originated Two Years Prior	201,124	265,946
Originated Three Years Prior	239,820	38,910
Originated Four Years Prior	31,360	14,900
Originated Five or More Years Prior	133,894	127,257
Revolving Loans	697,240	689,675
Gross loans	1,532,730	1,578,730
Gross write-off, current year	0	54
Gross write-off, one year prior	0	3,397
Gross write-off, two years prior	1,003	0
Gross write-off, three years prior	49	0
Gross write-off, four years prior	0	280
Gross write-off, five years prior	316	11,094
Gross write-off, revolving	1,918	63
Gross write-off	3,286	14,888	2,612
Commercial Portfolio Segment [Member] | Pass [Member]
Originated Current Fiscal Year	67,298	178,582
Originated One Year Prior	157,067	252,151
Originated Two Years Prior	194,602	265,705
Originated Three Years Prior	237,065	38,909
Originated Four Years Prior	29,717	13,726
Originated Five or More Years Prior	111,841	112,145
Revolving Loans	678,206	684,779
Gross loans	1,475,796	1,545,997
Commercial Portfolio Segment [Member] | Special Mention [Member]
Originated Current Fiscal Year	1,908	0
Originated One Year Prior	0	10,620
Originated Two Years Prior	2,817	0
Originated Three Years Prior	2,538	0
Originated Four Years Prior	1,643	562
Originated Five or More Years Prior	6,209	3,417
Revolving Loans	17,491	3,199
Gross loans	32,606	17,798
Commercial Portfolio Segment [Member] | Substandard [Member]
Originated Current Fiscal Year	0	250
Originated One Year Prior	3,019	439
Originated Two Years Prior	3,705	241
Originated Three Years Prior	217	1
Originated Four Years Prior	0	612
Originated Five or More Years Prior	15,844	11,695
Revolving Loans	1,543	1,697
Gross loans	24,328	14,935
Commercial Portfolio Segment [Member] | Doubtful [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Originated Current Fiscal Year	408,314	248,660
Originated One Year Prior	268,533	1,561,841
Originated Two Years Prior	1,481,673	1,586,997
Originated Three Years Prior	1,511,933	352,445
Originated Four Years Prior	341,305	354,646
Originated Five or More Years Prior	1,453,635	1,276,583
Revolving Loans	415,286	514,373
Gross loans	5,880,679	5,895,545
Gross write-off, current year	0	0
Gross write-off, one year prior	0	0
Gross write-off, two years prior	0	0
Gross write-off, three years prior	0	0
Gross write-off, four years prior	0	0
Gross write-off, five years prior	10,416	2,142
Gross write-off, revolving	0	0
Gross write-off	10,416	2,142	2,819
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Originated Current Fiscal Year	408,314	248,660
Originated One Year Prior	268,533	1,561,841
Originated Two Years Prior	1,424,209	1,585,109
Originated Three Years Prior	1,510,087	352,445
Originated Four Years Prior	339,553	353,391
Originated Five or More Years Prior	1,357,858	1,232,240
Revolving Loans	415,286	497,588
Gross loans	5,723,840	5,831,274
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	53,642	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	59,719	24,202
Revolving Loans	0	0
Gross loans	113,361	24,202
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	3,822	1,888
Originated Three Years Prior	1,846	0
Originated Four Years Prior	1,752	1,255
Originated Five or More Years Prior	36,058	20,141
Revolving Loans	0	16,785
Gross loans	43,478	40,069
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Commercial Construction Portfolio Segment [Member]
Originated Current Fiscal Year	15,390	582
Originated One Year Prior	0	5,463
Originated Two Years Prior	2,137	15,645
Originated Three Years Prior	8,995	6,236
Originated Four Years Prior	6,518	0
Originated Five or More Years Prior	0	0
Revolving Loans	583,206	592,570
Gross loans	616,246	620,496
Gross write-off, current year	0	0
Gross write-off, one year prior	0	0
Gross write-off, two years prior	0	0
Gross write-off, three years prior	0	0
Gross write-off, four years prior	0	0
Gross write-off, five years prior	0	0
Gross write-off, revolving	0	0
Gross write-off	0	0	(0)
Commercial Construction Portfolio Segment [Member] | Pass [Member]
Originated Current Fiscal Year	15,390	582
Originated One Year Prior	0	5,463
Originated Two Years Prior	2,137	15,645
Originated Three Years Prior	8,995	6,236
Originated Four Years Prior	6,518	0
Originated Five or More Years Prior	0	0
Revolving Loans	581,002	583,870
Gross loans	614,042	611,796
Commercial Construction Portfolio Segment [Member] | Special Mention [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	8,700
Gross loans	0	8,700
Commercial Construction Portfolio Segment [Member] | Substandard [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	2,204	0
Gross loans	2,204	0
Commercial Construction Portfolio Segment [Member] | Doubtful [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Residential Portfolio Segment [Member]
Originated Current Fiscal Year	17,763	15,455
Originated One Year Prior	14,542	42,830
Originated Two Years Prior	39,830	22,542
Originated Three Years Prior	21,925	21,704
Originated Four Years Prior	18,496	19,896
Originated Five or More Years Prior	97,656	93,909
Revolving Loans	39,479	39,705
Gross loans	249,691	256,041
Gross write-off, current year	0	0
Gross write-off, one year prior	0	0
Gross write-off, two years prior	0	0
Gross write-off, three years prior	0	0
Gross write-off, four years prior	0	0
Gross write-off, five years prior	0	0
Gross write-off, revolving	0	18
Gross write-off	0	18	9
Residential Portfolio Segment [Member] | Pass [Member]
Originated Current Fiscal Year	17,763	15,455
Originated One Year Prior	14,542	42,830
Originated Two Years Prior	39,197	21,987
Originated Three Years Prior	21,925	21,704
Originated Four Years Prior	17,339	19,896
Originated Five or More Years Prior	96,657	91,114
Revolving Loans	36,471	36,082
Gross loans	243,894	249,068
Residential Portfolio Segment [Member] | Special Mention [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	635	651
Revolving Loans	2,773	2,817
Gross loans	3,408	3,468
Residential Portfolio Segment [Member] | Substandard [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	633	555
Originated Three Years Prior	0	0
Originated Four Years Prior	1,157	0
Originated Five or More Years Prior	364	2,144
Revolving Loans	235	806
Gross loans	2,389	3,505
Residential Portfolio Segment [Member] | Doubtful [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Consumer Portfolio Segment [Member]
Originated Current Fiscal Year	1,015	849
Originated One Year Prior	24	83
Originated Two Years Prior	1	0
Originated Three Years Prior	0	5
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	96	92
Gross loans	1,136	1,029
Gross write-off, current year	0	0
Gross write-off, one year prior	0	0
Gross write-off, two years prior	0	0
Gross write-off, three years prior	0	0
Gross write-off, four years prior	0	0
Gross write-off, five years prior	0	0
Gross write-off, revolving	0	1
Gross write-off	0	1	$ 3
Consumer Portfolio Segment [Member] | Pass [Member]
Originated Current Fiscal Year	1,015	849
Originated One Year Prior	24	83
Originated Two Years Prior	1	0
Originated Three Years Prior	0	5
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	96	92
Gross loans	1,136	1,029
Consumer Portfolio Segment [Member] | Special Mention [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Consumer Portfolio Segment [Member] | Substandard [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	0	0
Consumer Portfolio Segment [Member] | Doubtful [Member]
Originated Current Fiscal Year	0	0
Originated One Year Prior	0	0
Originated Two Years Prior	0	0
Originated Three Years Prior	0	0
Originated Four Years Prior	0	0
Originated Five or More Years Prior	0	0
Revolving Loans	0	0
Gross loans	$ 0	$ 0