Note 5 - Allowances for Loan Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans receivable, total past due	$ 13,050	$ 15,958
Loans receivable, current	1,423,564	1,146,091
Loans receivable	1,436,614	1,162,049
Loans receivable greater than 90 days and accruing
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	1,135	1,113
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	1,574
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due	10,341	14,845
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, total past due	5,891	8,963
Loans receivable, current	509,847	424,341
Loans receivable	515,738	433,304
Loans receivable greater than 90 days and accruing
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	339
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	921
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due	4,631	8,963
Construction and Land Development Portfolio Segment [Member]
Loans receivable, total past due
Loans receivable, current	121,042	104,617
Loans receivable	121,042	104,617
Loans receivable greater than 90 days and accruing
Construction and Land Development Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due
Construction and Land Development Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due
Construction and Land Development Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due
Commercial Portfolio Segment [Member]
Loans receivable, total past due	3,941	3,864
Loans receivable, current	196,482	169,479
Loans receivable	200,423	173,343
Loans receivable greater than 90 days and accruing
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	280	969
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due	3,661	2,895
Owner Occupied Real Estate [Member]
Loans receivable, total past due	1,841	2,136
Loans receivable, current	366,054	307,702
Loans receivable	367,895	309,838
Loans receivable greater than 90 days and accruing
Owner Occupied Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due
Owner Occupied Real Estate [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due	653
Owner Occupied Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due	1,188	2,136
Consumer Portfolio Segment [Member]
Loans receivable, total past due	1,075	995
Loans receivable, current	90,077	75,188
Loans receivable	91,152	76,183
Loans receivable greater than 90 days and accruing
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	214	144
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due	861	851
Residential Portfolio Segment [Member]
Loans receivable, total past due	302
Loans receivable, current	140,062	64,764
Loans receivable	140,364	64,764
Loans receivable greater than 90 days and accruing
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, total past due	302
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, total past due
Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, total past due