Note 21 - Regulatory Matters - Risk Based Capital Amounts and Ratios (Details) $ in Thousands		Mar. 31, 2022 USD ($)		Dec. 31, 2021 USD ($)
Total risk-based capital, actual amount	[1]	$ 681,421		$ 596,411
Total risk-based capital, actual ratio	[1]	0.1214		0.1279
Total risk-based capital, minimum for adequately capitalized amount	[1]	$ 448,875		$ 372,929
Total risk-based capital, minimum for adequately capitalized ratio	[1]	0.0800		0.0800
Common Equity Tier 1 risk-based capital, actual amount		$ 597,949	[1]	$ 556,590
Common Equity Tier 1 risk-based capital, actual ratio		0.1066	[1]	0.1194
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount		$ 252,492	[1]	$ 209,772
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]	$ 623,949	[2]	$ 556,590
Tier 1 risk-based capita, actual ratio	[1]	0.1112		0.1194
Tier 1 risk-based capital, minimum for adequately capitalized amount	[1]	$ 336,656		$ 279,696
Tier 1 risk-based capital, minimum for adequately capitalized ratio	[1]	0.0600		0.0600
Tier 1 risk-based capital, actual amount	[1]	$ 623,949	[2]	$ 556,590
Leverage, actual ratio	[2]	0.0934		0.0886
Leverage, minimum for adequately capitalized amount	[2]	$ 267,229		$ 251,348
Leverage, minimum for adequately capitalized ratio		0.0400	[1]	0.0400	[2]
Leverage, actual amount	[2]			$ 556,590
Subsidiaries [Member]
Total risk-based capital, actual amount	[1]	$ 634,467		$ 577,078
Total risk-based capital, actual ratio	[1]	0.1134		0.1242
Total risk-based capital, minimum for adequately capitalized amount	[1]	$ 447,501		$ 371,809
Total risk-based capital, minimum for adequately capitalized ratio	[1]	0.0800		0.0800
Total risk-based capital, minimum for well capitalized amount	[1]	$ 559,337		$ 464,761
Total risk-based capital, minimum for well capitalized ratio	[1]	0.100		0.1000
Common Equity Tier 1 risk-based capital, actual amount		$ 576,995	[1]	$ 537,257
Common Equity Tier 1 risk-based capital, actual ratio		0.1031	[1]	0.1156
Common Equity Tier 1 risk-based capital, minimum for adequately capitalized amount		$ 251,719	[1]	$ 209,142
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		$ 363,595	[1]	$ 302,095
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]	$ 576,995		$ 537,257
Tier 1 risk-based capita, actual ratio	[1]	0.1031		0.1156
Tier 1 risk-based capital, minimum for adequately capitalized amount	[1]	$ 335,626		$ 278,857
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]	$ 447,501		$ 371,809
Tier 1 risk-based capital, minimum for well capitalized ratio	[1]	0.080		0.0800
Tier 1 risk-based capital, actual amount	[1]	$ 576,995		$ 537,257
Leverage, actual ratio	[2]	0.0865		0.0857
Leverage, minimum for adequately capitalized amount	[2]	$ 266,683		$ 250,871
Leverage, minimum for adequately capitalized ratio	[2]	0.0400		0.0400
Leverage, actual amount	[2]	$ 576,995		$ 537,257
Leverage, minimum for well capitalized amount	[2]	$ 333,354		$ 313,588
Leverage, minimum for well capitalized ratio	[2]	0.050		0.0500

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

[2] Ratio is computed in relation to average assets.