Note 4 - Loans and the Allowance for Credit Losses - Impairment Evaluation on Loans and Allowance for Credit Losses (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Individually evaluated		$ 8,479	$ 16,217
Collectively evaluated		77,955	58,358
Total		90,513	78,773	$ 79,226	$ 38,293
Individually evaluated		91,976	101,949
Collectively evaluated		8,006,720	6,722,164
Total		8,109,161	6,838,351
Financial Asset Acquired with Credit Deterioration [Member]
Individually evaluated		4,079	4,198
Individually evaluated		10,465	14,238
Commercial Portfolio Segment [Member]
Individually evaluated		7,426	15,131
Collectively evaluated		19,319	8,561
Total		28,903	25,969	28,443	8,349
Individually evaluated		30,994	33,726
Collectively evaluated		1,436,866	1,260,537
Total	[1]	1,472,734	1,299,428
Commercial Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Individually evaluated		2,158	2,277
Individually evaluated		4,874	5,165
Commercial Real Estate Portfolio Segment [Member]
Individually evaluated		1,003	955
Collectively evaluated		50,818	42,713
Total		53,742	45,589	39,330	20,853
Individually evaluated		46,886	49,310
Collectively evaluated		5,742,751	4,686,346
Total		5,795,228	4,741,590
Commercial Real Estate Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Individually evaluated		1,921	1,921
Individually evaluated		5,591	5,934
Commercial Construction Portfolio Segment [Member]
Individually evaluated		0	0
Collectively evaluated		3,718	3,580
Total		3,718	3,580	8,194	7,304
Individually evaluated		8,232	13,196
Collectively evaluated		565,907	526,982
Total		574,139	540,178
Commercial Construction Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Individually evaluated		0	0
Individually evaluated		0	0
Residential Portfolio Segment [Member]
Individually evaluated		50	131
Collectively evaluated		4,093	3,497
Total		4,143	3,628	2,687	1,685
Individually evaluated		5,864	5,717
Collectively evaluated		258,884	246,413
Total		264,748	255,269
Residential Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Individually evaluated		0	0
Individually evaluated		0	3,139
Consumer Portfolio Segment [Member]
Individually evaluated		0	0
Collectively evaluated		7	7
Total		7	7	$ 4	$ 3
Individually evaluated		0	0
Collectively evaluated		2,312	1,886
Total		2,312	1,886
Consumer Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Individually evaluated		0	0
Individually evaluated		$ 0	$ 0

[1] Included in commercial loans as of December 31, 2022 and December 31, 2021 were Paycheck Protection Program (“PPP”) loans of $11.4 million and $93.1 million, respectively. These loans are 100% federally guaranteed and currently not subject to any allocation of allowance for credit losses.