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Note 4 - Loans and Allowance for Loan Losses (Details) - Components of Loan Portfolio - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 2,277,727,000	$ 2,089,277,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	9.00%
Originated Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 1,616,587,000	$ 1,246,116,000	$ 1,053,243,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	29.70%
Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 661,140,000	$ 843,161,000
Percent of portfolio	100.00%	100.00%
Period increase (decrease)	(21.60%)
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 1,946,696,000	$ 1,715,303,000
Percent of portfolio	85.50%	82.10%
Period increase (decrease)	13.50%
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 696,303,000	$ 550,607,000
Percent of portfolio	30.60%	26.40%
Period increase (decrease)	26.50%
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)	$ 45,120,000	$ 51,974,000
Percent of portfolio	2.00%	2.50%
Period increase (decrease)	(13.20%)
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 445,919,000	$ 430,388,000
Percent of portfolio	19.60%	20.50%
Period increase (decrease)	3.60%
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)	$ 644,351,000	$ 559,574,000
Percent of portfolio	28.30%	26.80%
Period increase (decrease)	15.20%
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)	$ 115,003,000	$ 122,760,000
Percent of portfolio	5.00%	5.90%
Period increase (decrease)	(6.30%)
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 1,493,516,000	$ 1,153,189,000	986,696,000
Percent of portfolio	92.40%	92.50%
Period increase (decrease)	29.50%
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)	$ 577,872,000	$ 384,570,000
Percent of portfolio	35.70%	30.80%
Period increase (decrease)	50.30%
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)	$ 30,138,000	$ 29,826,000
Percent of portfolio	1.90%	2.40%
Period increase (decrease)	1.00%
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)	$ 330,798,000	$ 291,758,000
Percent of portfolio	20.50%	23.40%
Period increase (decrease)	13.40%
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)	$ 520,754,000	$ 410,977,000
Percent of portfolio	32.20%	33.00%
Period increase (decrease)	26.70%
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)	$ 33,954,000	$ 36,058,000
Percent of portfolio	2.10%	2.90%
Period increase (decrease)	(5.80%)
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 453,180,000	$ 562,114,000
Percent of portfolio	68.60%	66.60%
Period increase (decrease)	(19.40%)
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)	$ 118,431,000	$ 166,037,000
Percent of portfolio	17.90%	19.70%
Period increase (decrease)	(28.70%)
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)	$ 14,982,000	$ 22,148,000
Percent of portfolio	2.30%	2.60%
Period increase (decrease)	(32.40%)
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)	$ 115,121,000	$ 138,630,000
Percent of portfolio	17.40%	16.40%
Period increase (decrease)	(17.00%)
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)	$ 123,597,000	$ 148,597,000
Percent of portfolio	18.70%	17.60%
Period increase (decrease)	(16.80%)
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)	$ 81,049,000	$ 86,702,000
Percent of portfolio	12.30%	10.30%
Period increase (decrease)	(6.50%)
Retail Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 331,031,000	$ 373,974,000
Percent of portfolio	14.50%	17.90%
Period increase (decrease)	(11.50%)
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 140,646,000	$ 159,278,000
Percent of portfolio	6.20%	7.60%
Period increase (decrease)	(11.70%)
Retail Portfolio Segment [Member] | 1-4 Family Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 190,385,000	$ 214,696,000
Percent of portfolio	8.30%	10.30%
Period increase (decrease)	(11.30%)
Retail Portfolio Segment [Member] | Originated Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 123,071,000	$ 92,927,000	$ 66,547,000
Percent of portfolio	7.60%	7.50%
Period increase (decrease)	32.40%
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)	$ 67,816,000	$ 50,059,000
Percent of portfolio	4.20%	4.00%
Period increase (decrease)	35.50%
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)	$ 55,255,000	$ 42,868,000
Percent of portfolio	3.40%	3.50%
Period increase (decrease)	28.90%
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance of loans outstanding (in Dollars)	$ 207,960,000	$ 281,047,000
Percent of portfolio	31.40%	33.40%
Period increase (decrease)	(26.00%)
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)	$ 72,830,000	$ 109,219,000
Percent of portfolio	11.00%	13.00%
Period increase (decrease)	(33.30%)
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)	$ 135,130,000	$ 171,828,000
Percent of portfolio	20.40%	20.40%
Period increase (decrease)	(21.40%)

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5074-111524

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