Note 3 - Loans and Allowance for Loan Losses (Details) - Retail Credit Risk by Collateral Type - USD ($)	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 2,217,388,000	$ 2,089,277,000
Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,519,710,000	1,246,116,000	$ 1,186,713,000
Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	697,678,000	843,161,000
Retail Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	339,768,000	373,974,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	146,765,000	159,278,000
Retail Portfolio Segment [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	193,003,000	214,696,000
Retail Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	117,390,000	92,927,000	$ 82,911,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	65,671,000	50,059,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	51,719,000	42,868,000
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	222,378,000	281,047,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	81,094,000	109,219,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 141,284,000	$ 171,828,000