Note 3 - Loans and Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Loans	$ 2,441,314,000	$ 2,378,620,000
Originated Loan [Member]
Loans	1,973,739,000	1,884,548,000
Acquired Loan [Member]
Loans	467,575,000	494,072,000
Commercial Portfolio Segment [Member]
Loans	2,123,348,000	2,065,347,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Loans	1,803,409,000	1,728,898,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Loans	319,939,000	336,449,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	757,220,000	713,903,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	685,227,000	636,771,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	71,993,000	77,132,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	31,924,000	34,828,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	23,841,000	26,519,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	8,083,000	8,309,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	452,382,000	450,464,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	368,910,000	363,509,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	83,472,000	86,955,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	768,565,000	748,269,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	678,359,000	652,054,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	90,206,000	96,215,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Loans	113,257,000	117,883,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member]
Loans	47,072,000	50,045,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member]
Loans	66,185,000	67,838,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	471,570,000	440,219,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	37,236,000	40,911,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	14,994,000	16,378,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	1,756,000	1,887,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	266,147,000	238,890,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	34,189,000	36,246,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	553,441,000	542,294,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	52,796,000	57,671,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member]
Loans	29,421,000	29,793,000
Grades 1-4 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member]
Loans	38,612,000	39,574,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	206,434,000	190,170,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	33,417,000	35,233,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	8,767,000	10,046,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	6,002,000	6,164,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	100,967,000	123,517,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	47,471,000	49,255,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	124,918,000	109,304,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	36,001,000	37,040,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member]
Loans	16,925,000	19,082,000
Grades 5-7 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member]
Loans	27,274,000	28,015,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
Loans	7,223,000	6,382,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
Loans	1,340,000	988,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
Loans	80,000	95,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
Loans	325,000	258,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	1,796,000	1,102,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	1,812,000	1,454,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
Loans	0	456,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
Loans	1,409,000	1,504,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member]
Loans	726,000	1,170,000
Grades 8-9 [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member]
Loans	$ 299,000	$ 249,000