Note 20 - Regulatory Matters - Actual Capital Levels and Minimum Levels (Details) $ in Thousands	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
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	$ 468,113	$ 429,038
Total capital, ratio	0.138	0.131
Total capital minimum required for capital adequacy, amount	$ 271,325	$ 262,141
Total capital minimum required for capital adequacy, ratio	0.080	0.080
Tier 1 capital, amount	$ 430,146	$ 405,148
Tier 1 capital, ratio	0.127	0.124
Tier 1 capital minimum required for capital adequacy, amount	$ 203,494	$ 196,606
Tier 1 capital minimum required for capital adequacy, ratio	0.060	0.060
Common equity tier 1, amount	$ 384,658	$ 360,342
Common equity tier 1, ratio	0.113	0.110
Common equity tier 1 minimum required for capital adequacy, amount	$ 152,621	$ 147,454
Common equity tier 1 capital minimum required for capital adequacy, ratio	0.045	0.045
Tier 1 capital to average assets, amount	$ 430,146	$ 405,148
Tier 1 capital to average assets, ratio	0.098	0.113
Tier 1 capital to average assets, minimum required for capital adequacy, amount	$ 176,053	$ 143,689
Tier 1 capital to average assets minimum required for capital adequacy, ratio	0.040	0.040
Bank [Member]
Total capital, amount	$ 457,203	$ 424,917
Total capital, ratio	0.135	0.130
Total capital minimum required for capital adequacy, amount	$ 271,196	$ 262,088
Total capital minimum required for capital adequacy, ratio	0.080	0.080
Total capital to be well capitalized, amount	$ 338,995	$ 327,610
Total capital to be well capitalized, ratio	0.100	0.100
Tier 1 capital, amount	$ 419,236	$ 401,027
Tier 1 capital, ratio	0.124	0.122
Tier 1 capital minimum required for capital adequacy, amount	$ 203,397	$ 196,566
Tier 1 capital minimum required for capital adequacy, ratio	0.060	0.060
Tier 1 capital to be well capitalized, amount	$ 271,196	$ 262,088
Tier 1 capital to be well capitalized, ratio	0.080	0.080
Common equity tier 1, amount	$ 419,236	$ 401,027
Common equity tier 1, ratio	0.124	0.122
Common equity tier 1 minimum required for capital adequacy, amount	$ 152,548	$ 147,425
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	$ 220,347	$ 212,947
Common equity tier 1 capital to be well capitalized, ratio	0.065	0.065
Tier 1 capital to average assets, amount	$ 419,236	$ 401,027
Tier 1 capital to average assets, ratio	0.095	0.112
Tier 1 capital to average assets, minimum required for capital adequacy, amount	$ 175,999	$ 143,670
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	$ 219,999	$ 179,588
Tier 1 capital to average assets to be well capitalized, ratio	0.050	0.050