Note 12 - Regulatory Matters - Actual Capital Levels and Minimum Levels (Details) $ in Thousands	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Total capital minimum required for capital adequacy, ratio	0.105
Tier 1 capital minimum required for capital adequacy, ratio	0.085
Common equity tier 1 capital minimum required for capital adequacy, ratio	0.070
Consolidated Entities [Member]
Total capital, amount	$ 597,495	$ 565,143
Total capital, ratio	0.138	0.140
Total capital minimum required for capital adequacy, amount	$ 346,868	$ 324,101
Total capital minimum required for capital adequacy, ratio	0.080	0.080
Tier 1 capital, amount	$ 473,065	$ 456,133
Tier 1 capital, ratio	0.109	0.113
Tier 1 capital minimum required for capital adequacy, amount	$ 260,151	$ 243,076
Tier 1 capital minimum required for capital adequacy, ratio	0.060	0.060
Common equity tier 1, amount	$ 426,553	$ 409,963
Common equity tier 1, ratio	0.098	0.101
Common equity tier 1 minimum required for capital adequacy, amount	$ 195,114	$ 182,307
Common equity tier 1 capital minimum required for capital adequacy, ratio	0.045	0.045
Tier 1 capital to average assets, amount	$ 473,065	$ 456,133
Tier 1 capital to average assets, ratio	0.093	0.092
Tier 1 capital to average assets, minimum required for capital adequacy, amount	$ 203,286	$ 198,574
Tier 1 capital to average assets minimum required for capital adequacy, ratio	0.040	0.040
Bank [Member]
Total capital, amount	$ 582,487	$ 551,760
Total capital, ratio	0.134	0.136
Total capital minimum required for capital adequacy, amount	$ 346,698	$ 323,928
Total capital minimum required for capital adequacy, ratio	0.080	0.080
Total capital to be well capitalized, amount	$ 433,372	$ 404,910
Total capital to be well capitalized, ratio	0.100	0.100
Tier 1 capital, amount	$ 546,513	$ 516,397
Tier 1 capital, ratio	0.126	0.128
Tier 1 capital minimum required for capital adequacy, amount	$ 260,023	$ 242,946
Tier 1 capital minimum required for capital adequacy, ratio	0.060	0.060
Tier 1 capital to be well capitalized, amount	$ 346,698	$ 323,928
Tier 1 capital to be well capitalized, ratio	0.080	0.080
Common equity tier 1, amount	$ 546,513	$ 516,397
Common equity tier 1, ratio	0.126	0.128
Common equity tier 1 minimum required for capital adequacy, amount	$ 195,018	$ 182,210
Common equity tier 1 capital minimum required for capital adequacy, ratio	0.045	0.045
Common equity tier 1 capital to be well capitalized, amount	$ 281,692	$ 263,192
Common equity tier 1 capital to be well capitalized, ratio	0.065	0.065
Tier 1 capital to average assets, amount	$ 546,513	$ 516,397
Tier 1 capital to average assets, ratio	0.108	0.104
Tier 1 capital to average assets, minimum required for capital adequacy, amount	$ 203,201	$ 198,510
Tier 1 capital to average assets minimum required for capital adequacy, ratio	0.040	0.040
Tier 1 capital to average assets to be well capitalized, amount	$ 254,001	$ 248,137
Tier 1 capital to average assets to be well capitalized, ratio	0.050	0.050