Note 3 - Loans and Allowance for Loan Losses (Details) - Components of Loan Portfolio - USD ($)	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 2,295,668,000	$ 2,277,727,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	0.80%
Originated Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 1,687,476,000	$ 1,616,587,000	$ 1,328,713,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	4.40%
Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 608,192,000	$ 661,140,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	(8.00%)
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 1,974,450,000	$ 1,946,696,000
Percent of portfolio	86.00%	85.50%
Period increase (decrease)	1.40%
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 714,612,000	$ 696,303,000
Percent of portfolio	31.10%	30.60%
Period increase (decrease)	2.60%
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 39,630,000	$ 45,120,000
Percent of portfolio	1.70%	2.00%
Period increase (decrease)	(12.20%)
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 441,662,000	$ 445,919,000
Percent of portfolio	19.30%	19.60%
Period increase (decrease)	(1.00%)
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 666,013,000	$ 644,351,000
Percent of portfolio	29.00%	28.30%
Period increase (decrease)	3.40%
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 112,533,000	$ 115,003,000
Percent of portfolio	4.90%	5.00%
Period increase (decrease)	(2.10%)
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 1,562,777,000	$ 1,493,516,000	1,230,841,000
Percent of portfolio	92.60%	92.40%
Period increase (decrease)	4.60%
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 613,570,000	$ 577,872,000
Percent of portfolio	36.40%	35.70%
Period increase (decrease)	6.20%
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 28,451,000	$ 30,138,000
Percent of portfolio	1.70%	1.90%
Period increase (decrease)	(5.60%)
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 334,948,000	$ 330,798,000
Percent of portfolio	19.80%	20.50%
Period increase (decrease)	1.30%
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 549,226,000	$ 520,754,000
Percent of portfolio	32.50%	32.20%
Period increase (decrease)	5.50%
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 36,582,000	$ 33,954,000
Percent of portfolio	2.20%	2.10%
Period increase (decrease)	7.70%
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 411,673,000	$ 453,180,000
Percent of portfolio	67.70%	68.60%
Period increase (decrease)	(9.20%)
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 101,042,000	$ 118,431,000
Percent of portfolio	16.60%	17.90%
Period increase (decrease)	(14.70%)
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 11,179,000	$ 14,982,000
Percent of portfolio	1.90%	2.30%
Period increase (decrease)	(25.40%)
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 106,714,000	$ 115,121,000
Percent of portfolio	17.50%	17.40%
Period increase (decrease)	(7.30%)
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 116,787,000	$ 123,597,000
Percent of portfolio	19.20%	18.70%
Period increase (decrease)	(5.50%)
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 75,951,000	$ 81,049,000
Percent of portfolio	12.50%	12.30%
Period increase (decrease)	(6.30%)
Retail Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 321,218,000	$ 331,031,000
Percent of portfolio	14.00%	14.50%
Period increase (decrease)	(3.00%)
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 135,683,000	$ 140,646,000
Percent of portfolio	5.90%	6.20%
Period increase (decrease)	(3.50%)
Retail Portfolio Segment [Member] | 1-4 Family Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 185,535,000	$ 190,385,000
Percent of portfolio	8.10%	8.30%
Period increase (decrease)	(2.50%)
Retail Portfolio Segment [Member] | Originated Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 124,699,000	$ 123,071,000	$ 97,872,000
Percent of portfolio	7.40%	7.60%
Period increase (decrease)	1.30%
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 68,342,000	$ 67,816,000
Percent of portfolio	4.10%	4.20%
Period increase (decrease)	0.80%
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 56,357,000	$ 55,255,000
Percent of portfolio	3.30%	3.40%
Period increase (decrease)	2.00%
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 196,519,000	$ 207,960,000
Percent of portfolio	32.30%	31.40%
Period increase (decrease)	(5.50%)
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 67,341,000	$ 72,830,000
Percent of portfolio	11.10%	11.00%
Period increase (decrease)	(7.50%)
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 129,178,000	$ 135,130,000
Percent of portfolio	21.20%	20.40%
Period increase (decrease)	(4.40%)