Note 4 - Loans and Allowance for Loan Losses (Details) - Retail Credit Risk by Collateral Type - USD ($)	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 2,171,832,000	$ 2,089,277,000
Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,429,623,000	1,246,116,000	$ 1,145,097,000
Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	742,209,000	843,161,000
Retail Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	351,401,000	373,974,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	149,494,000	159,278,000
Retail Portfolio Segment [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	201,907,000	214,696,000
Retail Portfolio Segment [Member] | Originated Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	107,235,000	92,927,000	$ 68,488,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	60,417,000	50,059,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	46,818,000	42,868,000
Retail Portfolio Segment [Member] | Acquired Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	244,166,000	281,047,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	89,077,000	109,219,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 155,089,000	$ 171,828,000