Note 4 - Loans, Allowance for Loan Losses and Other Real Estate Owned - Loans by Delinquency and Nonaccrual Status (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current and accruing	$ 1,150,349	$ 1,193,853
Nonaccrual	3,847	4,868
Total	1,161,712	1,207,202
Financial Asset, 30 to 59 Days Past Due [Member]
Past due and accruing	6,446	5,595
Financial Asset, 60 to 89 Days Past Due [Member]
Past due and accruing	821	2,335
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due and accruing	249	551
Commercial Portfolio Segment [Member]
Current and accruing	243,187	274,045
Nonaccrual	100	0
Total	243,577	275,080
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due and accruing	290	781
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due and accruing	0	254
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Commercial Real Estate Portfolio Segment [Member]
Current and accruing	570,463	574,853
Nonaccrual	3,670	4,225
Total	577,665	580,480
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due and accruing	3,472	617
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due and accruing	60	785
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Construction Portfolio Segment [Member]
Current and accruing	5,482	3,982
Nonaccrual	0	0
Total	5,482	3,982
Construction Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due and accruing	0	0
Construction Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due and accruing	0	0
Construction Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Residential Portfolio Segment [Member]
Current and accruing	37,533	43,372
Nonaccrual	0	516
Total	37,813	44,866
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due and accruing	280	789
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due and accruing	0	189
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Consumer Portfolio Segment [Member]
Current and accruing	293,684	297,601
Nonaccrual	77	127
Total	297,175	302,794
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Past due and accruing	2,404	3,408
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Past due and accruing	761	1,107
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past due and accruing	$ 249	$ 551