Note 4 - Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans	$ 2,378,620,000	$ 2,277,727,000
Originated Loan [Member]
Loans	1,884,548,000	1,616,587,000	$ 1,246,116,000
Acquired Loan [Member]
Loans	494,072,000	661,140,000
Commercial Portfolio Segment [Member]
Loans	2,065,347,000	1,946,696,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Loans	1,728,898,000	1,493,516,000	$ 1,153,189,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Loans	336,449,000	453,180,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	713,903,000	696,303,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	636,771,000	577,872,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	77,132,000	118,431,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	34,828,000	45,120,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	26,519,000	30,138,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	8,309,000	14,982,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	450,464,000	445,919,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	363,509,000	330,798,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	86,955,000	115,121,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	748,269,000	644,351,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	652,054,000	520,754,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	96,215,000	123,597,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	117,883,000	115,003,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Originated Loan [Member]
Loans	50,045,000	33,954,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Acquired Loan [Member]
Loans	67,838,000	81,049,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	440,219,000	417,120,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	40,911,000	67,978,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	16,378,000	18,118,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	1,887,000	3,095,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	238,890,000	230,629,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	36,246,000	45,807,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	542,294,000	400,350,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	57,671,000	71,197,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Originated Loan [Member]
Loans	29,793,000	19,121,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Acquired Loan [Member]
Loans	39,574,000	44,763,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	190,170,000	160,454,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	35,233,000	47,589,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	10,046,000	10,365,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	6,164,000	11,364,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	123,517,000	98,332,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	49,255,000	63,563,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	109,304,000	120,404,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	37,040,000	50,066,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Originated Loan [Member]
Loans	19,082,000	13,806,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Acquired Loan [Member]
Loans	28,015,000	35,288,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	6,382,000	298,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	988,000	2,864,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	95,000	1,655,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	258,000	523,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	1,102,000	1,837,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	1,454,000	5,751,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	456,000	0
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	1,504,000	2,334,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Originated Loan [Member]
Loans	1,170,000	1,027,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Acquired Loan [Member]
Loans	$ 249,000	$ 998,000