Note 22 - Regulatory Matters - Risk Based Capital Amounts and Ratios (Details) $ in Thousands		Mar. 31, 2023 USD ($)		Dec. 31, 2022 USD ($)
Total risk-based capital, actual amount	[1]	$ 786,853		$ 762,956
Total risk-based capital, actual ratio	[1]	0.1291		0.1254
Total risk-based capital, minimum for adequately capitalized amount	[1]	$ 487,733		$ 486,841
Total risk-based capital, minimum for adequately capitalized ratio	[1]	0.0800		0.0800
Common Equity Tier 1 risk-based capital, actual amount		$ 689,044	[1]	$ 672,045
Common Equity Tier 1 risk-based capital, actual ratio		0.1130	[1]	0.1104
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount		$ 274,350	[1]	$ 273,848
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized ratio		0.0450	[1]	0.0450
Tier 1 risk-based capital, actual amount	[1]	$ 715,044		$ 698,045
Tier 1 risk-based capita, actual ratio	[1]	0.1173		0.1147
Tier 1 risk-based capital, minimum for adequately capitalized amount	[1]	$ 365,800		$ 365,131
Tier 1 risk-based capital, minimum for adequately capitalized ratio	[1]	0.0600		0.0600
Tier 1 risk-based capital, actual amount	[1]	$ 715,044		$ 698,045
Leverage, actual ratio		0.0956		0.0933
Leverage, minimum for adequately capitalized amount		$ 299,234		$ 299,329
Leverage, minimum for adequately capitalized ratio		0.0400	[1]	0.0400
Leverage, actual amount				$ 698,045
Subsidiaries [Member]
Total risk-based capital, actual amount	[1]	$ 763,743		$ 732,688
Total risk-based capital, actual ratio	[1]	0.1257		0.1208
Total risk-based capital, minimum for adequately capitalized amount	[1]	$ 486,086		$ 485,314
Total risk-based capital, minimum for adequately capitalized ratio	[1]	0.0800		0.0800
Total risk-based capital, minimum for well capitalized amount	[1]	$ 607,608		$ 606,643
Total risk-based capital, minimum for well capitalized ratio	[1]	0.100		0.1000
Common Equity Tier 1 risk-based capital, actual amount		$ 691,934	[1]	$ 667,777
Common Equity Tier 1 risk-based capital, actual ratio		0.1139	[1]	0.1101
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount		$ 273,423	[1]	$ 272,989
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized ratio		0.0450	[1]	0.0450
Common Equity Tier 1 risk-based capital, minimum for well capitalized amount		$ 394,945	[1]	$ 394,318
Common Equity Tier 1 risk-based capital, minimum for well capitalized ratio		0.065	[1]	0.0650
Tier 1 risk-based capital, actual amount	[1]	$ 691,934		$ 667,777
Tier 1 risk-based capita, actual ratio	[1]	0.1139		0.1101
Tier 1 risk-based capital, minimum for adequately capitalized amount	[1]	$ 364,565		$ 363,986
Tier 1 risk-based capital, minimum for adequately capitalized ratio	[1]	0.0600		0.0600
Tier 1 risk-based capital, minimum for well capitalized amount	[1]	$ 486,086		$ 485,314
Tier 1 risk-based capital, minimum for well capitalized ratio	[1]	0.080		0.0800
Tier 1 risk-based capital, actual amount	[1]	$ 691,934		$ 667,777
Leverage, actual ratio		0.0923		0.0895
Leverage, minimum for adequately capitalized amount		$ 298,876		$ 298,600
Leverage, minimum for adequately capitalized ratio		0.0400		0.0400
Leverage, actual amount		$ 691,934		$ 667,777
Leverage, minimum for well capitalized amount		$ 373,595		$ 373,250
Leverage, minimum for well capitalized ratio		0.050		0.0500

[1] Ratio is computed in relation to risk-weighted assets.