Note 3 - Loans - Aging of the Recorded Investment in Loans (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Commercial and Industrial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due	$ 587,000	$ 238,000
Commercial and Industrial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due	96,000	327,000
Commercial and Industrial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due	1,794,000	3,643,000
Commercial and Industrial Portfolio Segment [Member]
Past due	2,477,000	4,208,000
Current	719,479,000	640,190,000
Loans	721,956,000	644,398,000
Recorded investment greater than 90 days and accruing
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Past due
Current	136,029,000	134,482,000
Loans	136,029,000	134,482,000
Recorded investment greater than 90 days and accruing
Undevelopment Land Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due
Undevelopment Land Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due
Undevelopment Land Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due
Undevelopment Land Portfolio Segment [Member]
Past due
Current	20,342,000	21,185,000
Loans	20,342,000	21,185,000
Recorded investment greater than 90 days and accruing
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Investment [Member]
Past due		290,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Commercial [Member]
Past due	1,367,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | One to Four Family Residential [Member]
Past due	1,428,000	1,147,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity First Lien [Member]
Past due	78,000	35,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity Junior Lien [Member]
Past due	79,000	285,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due	2,952,000	1,757,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Investment [Member]
Past due	200,000	140,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Commercial [Member]
Past due	734,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | One to Four Family Residential [Member]
Past due	227,000	94,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity First Lien [Member]
Past due	25,000	51,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity Junior Lien [Member]
Past due	259,000	173,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due	1,445,000	458,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Investment [Member]
Past due	420,000	278,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Owner Occupied Commercial [Member]
Past due	1,836,000	2,761,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | One to Four Family Residential [Member]
Past due	1,046,000	1,082,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity First Lien [Member]
Past due		13,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity Junior Lien [Member]
Past due	253,000	92,000
Real Estate Mortgage Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due	3,555,000	4,226,000
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Past due	620,000	708,000
Current	571,818,000	527,582,000
Loans	572,438,000	528,290,000
Recorded investment greater than 90 days and accruing	140,000
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Past due	3,937,000	2,761,000
Current	329,925,000	326,604,000
Loans	333,862,000	329,365,000
Recorded investment greater than 90 days and accruing	201,000
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Past due	2,701,000	2,323,000
Current	238,069,000	224,252,000
Loans	240,770,000	226,575,000
Recorded investment greater than 90 days and accruing	69,000	176,000
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Past due	103,000	99,000
Current	52,257,000	50,016,000
Loans	52,360,000	50,115,000
Recorded investment greater than 90 days and accruing
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Past due	591,000	550,000
Current	65,408,000	62,516,000
Loans	65,999,000	63,066,000
Recorded investment greater than 90 days and accruing
Real Estate Mortgage Portfolio Segment [Member]
Past due	7,952,000	6,441,000
Current	1,257,477,000	1,190,970,000
Loans	1,265,429,000	1,197,411,000
Recorded investment greater than 90 days and accruing	410,000	176,000
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due		343,000
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due		8,000
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due	31,000
Consumer Portfolio Segment [Member]
Past due	31,000	351,000
Current	31,764,000	35,180,000
Loans	31,795,000	35,531,000
Recorded investment greater than 90 days and accruing
Financing Receivables, 30 to 59 Days Past Due [Member]
Past due	3,539,000	2,338,000
Financing Receivables, 60 to 89 Days Past Due [Member]
Past due	1,541,000	793,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due	5,380,000	7,869,000
Past due	10,460,000	11,000,000
Current	2,165,091,000	2,022,007,000
Loans	2,175,551,000	2,033,007,000
Recorded investment greater than 90 days and accruing	$ 410,000	$ 176,000