Note 5 - Allowances for Loan Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Loans receivable, total past due	$ 14,348	$ 13,050
Loans receivable, current	1,733,748	1,423,564
Loans receivable	1,748,096	1,436,614
Loans receivable greater than 90 days and accruing
Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	112	1,135
Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	1,823	1,574
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due	12,413	10,341
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, total past due	4,472	5,891
Loans receivable, current	609,159	509,847
Loans receivable	613,631	515,738
Loans receivable greater than 90 days and accruing
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due		339
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	313	921
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due	4,159	4,631
Construction and Land Development Portfolio Segment [Member]
Loans receivable, total past due
Loans receivable, current	121,395	121,042
Loans receivable	121,395	121,042
Loans receivable greater than 90 days and accruing
Construction and Land Development Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due
Construction and Land Development Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due
Construction and Land Development Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due
Commercial Portfolio Segment [Member]
Loans receivable, total past due	3,137	3,941
Loans receivable, current	220,769	196,482
Loans receivable	223,906	200,423
Loans receivable greater than 90 days and accruing
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due		280
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	50
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due	3,087	3,661
Owner Occupied Real Estate [Member]
Loans receivable, total past due	4,556	1,841
Loans receivable, current	419,844	366,054
Loans receivable	424,400	367,895
Loans receivable greater than 90 days and accruing
Owner Occupied Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due
Owner Occupied Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	1,219	653
Owner Occupied Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due	3,337	1,188
Consumer Portfolio Segment [Member]
Loans receivable, total past due	1,415	1,075
Loans receivable, current	99,905	90,077
Loans receivable	101,320	91,152
Loans receivable greater than 90 days and accruing
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	112	214
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	241
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due	1,062	861
Residential Portfolio Segment [Member]
Loans receivable, total past due	768	302
Loans receivable, current	262,676	140,062
Loans receivable	263,444	140,364
Loans receivable greater than 90 days and accruing
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, total past due		302
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, total past due
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, total past due	$ 768