Note 3 - Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	$ 455,134,000	$ 417,120,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	19,014,000	18,118,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	237,652,000	230,629,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	491,928,000	400,350,000
Originated Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	20,438,000	19,121,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	197,701,000	160,454,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	11,093,000	10,365,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	99,961,000	98,332,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	111,308,000	120,404,000
Originated Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	17,816,000	13,806,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	300,000	298,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	125,000	1,655,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	1,296,000	1,837,000
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	0	0
Originated Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	979,000	1,027,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	653,135,000	577,872,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	30,232,000	30,138,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	338,909,000	330,798,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	603,236,000	520,754,000
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	39,233,000	33,954,000
Originated Loan [Member] | Commercial Portfolio Segment [Member]
Loans	1,664,745,000	1,493,516,000	$ 1,322,388,000
Originated Loan [Member]
Loans	1,799,954,000	1,616,587,000	$ 1,429,623,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	50,716,000	67,978,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	2,322,000	3,095,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	41,217,000	45,807,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	70,569,000	71,197,000
Acquired Loan [Member] | Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	42,729,000	44,763,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	43,819,000	47,589,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	7,648,000	11,364,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	55,364,000	63,563,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	41,431,000	50,066,000
Acquired Loan [Member] | Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	30,692,000	35,288,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	2,466,000	2,864,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	327,000	523,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	3,308,000	5,751,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	1,694,000	2,334,000
Acquired Loan [Member] | Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	708,000	998,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	97,001,000	118,431,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	10,297,000	14,982,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	99,889,000	115,121,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	113,694,000	123,597,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	74,129,000	81,049,000
Acquired Loan [Member] | Commercial Portfolio Segment [Member]
Loans	395,010,000	453,180,000
Acquired Loan [Member]
Loans	579,986,000	661,140,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	750,136,000	696,303,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	40,529,000	45,120,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	438,798,000	445,919,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	716,930,000	644,351,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	113,362,000	115,003,000
Commercial Portfolio Segment [Member]
Loans	2,059,755,000	1,946,696,000
Loans	$ 2,379,940,000	$ 2,277,727,000