Note 3 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Originated Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	4	9	6
Loans modified, pre-modification recorded principal balance	$ 0	$ 22,781,000	$ 1,876,000	$ 23,923,000
Loans modified, post-modification recorded principal balance	$ 0	$ 22,881,000	$ 1,901,000	$ 24,023,000
Acquired Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	1	0	11	0
Loans modified, pre-modification recorded principal balance	$ 237,000	$ 0	$ 1,209,000	$ 0
Loans modified, post-modification recorded principal balance	$ 237,000	$ 0	$ 1,209,000	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	4	9	6
Loans modified, pre-modification recorded principal balance	$ 0	$ 22,781,000	$ 1,876,000	$ 23,923,000
Loans modified, post-modification recorded principal balance	$ 0	$ 22,881,000	$ 1,901,000	$ 24,023,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	2	9	2
Loans modified, pre-modification recorded principal balance	$ 0	$ 5,994,000	$ 1,876,000	$ 5,994,000
Loans modified, post-modification recorded principal balance	$ 0	$ 6,094,000	$ 1,901,000	$ 6,094,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	2	0	3
Loans modified, pre-modification recorded principal balance	$ 0	$ 16,787,000	$ 0	$ 17,783,000
Loans modified, post-modification recorded principal balance	$ 0	$ 16,787,000	$ 0	$ 17,783,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	1
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 146,000
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 146,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	1	0	11	0
Loans modified, pre-modification recorded principal balance	$ 237,000	$ 0	$ 1,209,000	$ 0
Loans modified, post-modification recorded principal balance	$ 237,000	$ 0	$ 1,209,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	2	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 286,000	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 286,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	3	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 66,000	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 66,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	1	0	4	0
Loans modified, pre-modification recorded principal balance	$ 237,000	$ 0	$ 655,000	$ 0
Loans modified, post-modification recorded principal balance	$ 237,000	$ 0	$ 655,000	$ 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	2	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 202,000	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 202,000	$ 0
Retail Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Loans modified, number of contracts	0	0	0	0
Loans modified, pre-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0
Loans modified, post-modification recorded principal balance	$ 0	$ 0	$ 0	$ 0