Note 3 - Loans (Details) - Aging of the Recorded Investment in Loans - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 12,839	$ 15,589
Current	1,941,586	1,852,961
Loans	1,954,425	1,868,550
Recorded investment greater than 90 days and accruing	544	329
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,650	8,508
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,071	1,553
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	10,118	5,528
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	5,820	5,245
Current	605,057	566,509
Loans	610,877	571,754
Recorded investment greater than 90 days and accruing	0	1
Commercial and Industrial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	26	3,860
Commercial and Industrial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	25	3
Commercial and Industrial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	5,769	1,382
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	26	826
Current	109,844	94,907
Loans	109,870	95,733
Recorded investment greater than 90 days and accruing	0	241
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	69
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	26	757
Undevelopment Land Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Current	18,950	21,268
Loans	18,950	21,268
Recorded investment greater than 90 days and accruing	0	0
Undevelopment Land Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Undevelopment Land Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Undevelopment Land Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Real Estate Mortgage Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	6,942	9,457
Current	1,176,660	1,140,942
Loans	1,183,602	1,150,399
Recorded investment greater than 90 days and accruing	544	87
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,588	4,536
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,046	1,532
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	4,308	3,389
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	712	1,477
Current	490,459	486,345
Loans	491,171	487,822
Recorded investment greater than 90 days and accruing	0	0
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	427	993
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	249
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	285	235
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	3,417	4,273
Current	354,211	336,709
Loans	357,628	340,982
Recorded investment greater than 90 days and accruing	0	0
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	268	1,272
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	114	920
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	3,035	2,081
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,408	3,109
Current	220,235	208,439
Loans	222,643	211,548
Recorded investment greater than 90 days and accruing	544	73
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	814	1,801
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	734	285
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	860	1,023
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	180	14
Current	49,757	43,765
Loans	49,937	43,779
Recorded investment greater than 90 days and accruing	0	14
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	17	0
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	72	0
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	91	14
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	225	584
Current	61,998	65,684
Loans	62,223	66,268
Recorded investment greater than 90 days and accruing	0
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	62	470
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	126	78
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	37	36
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	51	61
Current	31,075	29,335
Loans	31,126	29,396
Recorded investment greater than 90 days and accruing	0	0
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	36	43
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	18
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 15	$ 0