Note 12 - Regulatory Matters - Actual Capital Levels and Minimum Levels (Details) $ in Thousands	Mar. 31, 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	$ 587,976	$ 565,143
Total capital, ratio	0.141	0.140
Total capital minimum required for capital adequacy, amount	$ 333,754	$ 324,101
Total capital minimum required for capital adequacy, ratio	0.080	0.080
Tier 1 capital, amount	$ 464,396	$ 456,133
Tier 1 capital, ratio	0.111	0.113
Tier 1 capital minimum required for capital adequacy, amount	$ 250,315	$ 243,076
Tier 1 capital minimum required for capital adequacy, ratio	0.060	0.060
Common equity tier 1, amount	$ 418,055	$ 409,963
Common equity tier 1, ratio	0.100	0.101
Common equity tier 1 minimum required for capital adequacy, amount	$ 187,737	$ 182,307
Common equity tier 1 capital minimum required for capital adequacy, ratio	0.045	0.045
Tier 1 capital to average assets, amount	$ 464,396	$ 456,133
Tier 1 capital to average assets, ratio	0.090	0.092
Tier 1 capital to average assets, minimum required for capital adequacy, amount	$ 205,492	$ 198,574
Tier 1 capital to average assets minimum required for capital adequacy, ratio	0.040	0.040
Bank [Member]
Total capital, amount	$ 574,013	$ 551,760
Total capital, ratio	0.138	0.136
Total capital minimum required for capital adequacy, amount	$ 333,587	$ 323,928
Total capital minimum required for capital adequacy, ratio	0.080	0.080
Total capital to be well capitalized, amount	$ 416,984	$ 404,910
Total capital to be well capitalized, ratio	0.100	0.100
Tier 1 capital, amount	$ 538,860	$ 516,397
Tier 1 capital, ratio	0.129	0.128
Tier 1 capital minimum required for capital adequacy, amount	$ 250,191	$ 242,946
Tier 1 capital minimum required for capital adequacy, ratio	0.060	0.060
Tier 1 capital to be well capitalized, amount	$ 333,587	$ 323,928
Tier 1 capital to be well capitalized, ratio	0.080	0.080
Common equity tier 1, amount	$ 538,860	$ 516,397
Common equity tier 1, ratio	0.129	0.128
Common equity tier 1 minimum required for capital adequacy, amount	$ 187,643	$ 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	$ 271,040	$ 263,192
Common equity tier 1 capital to be well capitalized, ratio	0.065	0.065
Tier 1 capital to average assets, amount	$ 538,860	$ 516,397
Tier 1 capital to average assets, ratio	0.105	0.104
Tier 1 capital to average assets, minimum required for capital adequacy, amount	$ 205,409	$ 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	$ 256,761	$ 248,137
Tier 1 capital to average assets to be well capitalized, ratio	0.050	0.050