Note 21 - Regulatory Matters - Risk Based Capital Amounts and Ratios (Details) $ in Thousands	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Total risk-based capital, actual amount	$ 894,490	$ 849,836
Total risk-based capital, actual ratio	0.1262	0.1256
Total risk-based capital, minimum for adequately capitalized amount	$ 567,068	$ 541,370
Total risk-based capital, minimum for adequately capitalized ratio	0.08	0.08
Common Equity Tier 1 risk-based capital, actual amount	$ 784,392	$ 747,376
Common Equity Tier 1 risk-based capital, actual ratio	0.1107	0.1104
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount	$ 318,976	$ 304,521
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized ratio	0.045	0.045
Tier 1 risk-based capital, actual amount	$ 810,392	$ 773,376
Tier 1 risk-based capita, actual ratio	0.1143	0.1143
Tier 1 risk-based capital, minimum for adequately capitalized amount	$ 425,301	$ 406,027
Tier 1 risk-based capital, minimum for adequately capitalized ratio	0.06	0.06
Leverage, actual amount		$ 773,376
Leverage, actual ratio	0.0995	0.0962
Leverage, minimum for adequately capitalized amount	$ 325,800	$ 321,713
Leverage, minimum for adequately capitalized ratio	0.04	0.04
Subsidiaries [Member]
Total risk-based capital, actual amount	$ 872,627	$ 823,275
Total risk-based capital, actual ratio	0.1235	0.1221
Total risk-based capital, minimum for adequately capitalized amount	$ 565,310	$ 539,609
Total risk-based capital, minimum for adequately capitalized ratio	0.08	0.08
Total risk-based capital, minimum for well capitalized amount	$ 706,637	$ 674,511
Total risk-based capital, minimum for well capitalized ratio	0.10	0.10
Common Equity Tier 1 risk-based capital, actual amount	$ 788,529	$ 746,815
Common Equity Tier 1 risk-based capital, actual ratio	0.1116	0.1107
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount	$ 317,987	$ 303,530
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized ratio	0.045	0.045
Common Equity Tier 1 risk-based capital, minimum for well capitalized amount	$ 459,314	$ 438,432
Common Equity Tier 1 risk-based capital, minimum for well capitalized ratio	0.065	0.065
Tier 1 risk-based capital, actual amount	$ 788,529	$ 746,815
Tier 1 risk-based capita, actual ratio	0.1116	0.1107
Tier 1 risk-based capital, minimum for adequately capitalized amount	$ 423,982	$ 404,707
Tier 1 risk-based capital, minimum for adequately capitalized ratio	0.06	0.06
Tier 1 risk-based capital, minimum for well capitalized amount	$ 565,310	$ 539,609
Tier 1 risk-based capital, minimum for well capitalized ratio	0.08	0.08
Leverage, actual amount	$ 788,529	$ 746,815
Leverage, actual ratio	0.0969	0.093
Leverage, minimum for adequately capitalized amount	$ 325,623	$ 321,323
Leverage, minimum for adequately capitalized ratio	0.04	0.04
Leverage, minimum for well capitalized amount	$ 407,029	$ 401,654
Leverage, minimum for well capitalized ratio	0.05	0.05