Note 4 - Loans and Allowance for Loan Losses - Components of Loan Portfolio (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans	$ 2,378,620,000	$ 2,277,727,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	4.40%
Commercial Portfolio Segment [Member]
Loans	$ 2,065,347,000	$ 1,946,696,000
Percent of portfolio	86.80%	85.50%
Period increase (decrease)	6.10%
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	$ 713,903,000	$ 696,303,000
Percent of portfolio	30.00%	30.60%
Period increase (decrease)	2.50%
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	$ 34,828,000	$ 45,120,000
Percent of portfolio	1.50%	2.00%
Period increase (decrease)	(22.80%)
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	$ 450,464,000	$ 445,919,000
Percent of portfolio	18.90%	19.60%
Period increase (decrease)	1.00%
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	$ 748,269,000	$ 644,351,000
Percent of portfolio	31.50%	28.30%
Period increase (decrease)	16.10%
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	$ 117,883,000	$ 115,003,000
Percent of portfolio	4.90%	5.00%
Period increase (decrease)	2.50%
Retail Portfolio Segment [Member]
Loans	$ 313,273,000	$ 331,031,000
Percent of portfolio	13.20%	14.50%
Period increase (decrease)	(5.40%)
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Loans	$ 118,047,000	$ 140,646,000
Percent of portfolio	5.00%	6.20%
Period increase (decrease)	(16.10%)
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Loans	$ 195,226,000	$ 190,385,000
Percent of portfolio	8.20%	8.30%
Period increase (decrease)	2.50%
Originated Loan [Member]
Loans	$ 1,884,548,000	$ 1,616,587,000	$ 1,246,116,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	16.60%
Originated Loan [Member] | Commercial Portfolio Segment [Member]
Loans	$ 1,728,898,000	$ 1,493,516,000	1,153,189,000
Percent of portfolio	91.70%	92.40%
Period increase (decrease)	15.80%
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	$ 636,771,000	$ 577,872,000
Percent of portfolio	33.80%	35.70%
Period increase (decrease)	10.20%
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	$ 26,519,000	$ 30,138,000
Percent of portfolio	1.40%	1.90%
Period increase (decrease)	(12.00%)
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	$ 363,509,000	$ 330,798,000
Percent of portfolio	19.30%	20.50%
Period increase (decrease)	9.90%
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	$ 652,054,000	$ 520,754,000
Percent of portfolio	34.60%	32.20%
Period increase (decrease)	25.20%
Originated Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	$ 50,045,000	$ 33,954,000
Percent of portfolio	2.60%	2.10%
Period increase (decrease)	47.40%
Originated Loan [Member] | Retail Portfolio Segment [Member]
Loans	$ 155,650,000	$ 123,071,000	$ 92,927,000
Percent of portfolio	8.30%	7.60%
Period increase (decrease)	26.50%
Originated Loan [Member] | Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Loans	$ 69,831,000	$ 67,816,000
Percent of portfolio	3.70%	4.20%
Period increase (decrease)	3.00%
Originated Loan [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Loans	$ 85,819,000	$ 55,255,000
Percent of portfolio	4.60%	3.40%
Period increase (decrease)	55.30%
Acquired Loan [Member]
Loans	$ 494,072,000	$ 661,140,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	(25.30%)
Acquired Loan [Member] | Commercial Portfolio Segment [Member]
Loans	$ 336,449,000	$ 453,180,000
Percent of portfolio	68.10%	68.60%
Period increase (decrease)	(25.80%)
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Loans	$ 77,132,000	$ 118,431,000
Percent of portfolio	15.60%	17.90%
Period increase (decrease)	(34.90%)
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Loans	$ 8,309,000	$ 14,982,000
Percent of portfolio	1.70%	2.30%
Period increase (decrease)	(44.50%)
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Loans	$ 86,955,000	$ 115,121,000
Percent of portfolio	17.60%	17.40%
Period increase (decrease)	(24.50%)
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Loans	$ 96,215,000	$ 123,597,000
Percent of portfolio	19.50%	18.70%
Period increase (decrease)	(22.20%)
Acquired Loan [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member]
Loans	$ 67,838,000	$ 81,049,000
Percent of portfolio	13.70%	12.30%
Period increase (decrease)	(16.30%)
Acquired Loan [Member] | Retail Portfolio Segment [Member]
Loans	$ 157,623,000	$ 207,960,000
Percent of portfolio	31.90%	31.40%
Period increase (decrease)	(24.20%)
Acquired Loan [Member] | Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Loans	$ 48,216,000	$ 72,830,000
Percent of portfolio	9.80%	11.00%
Period increase (decrease)	(33.80%)
Acquired Loan [Member] | Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Loans	$ 109,407,000	$ 135,130,000
Percent of portfolio	22.10%	20.40%
Period increase (decrease)	(19.00%)