Note 4 - Loans and Allowance for Loan Losses (Details) - Loans by Credit Risk Rating, Segregated by Class of Loans (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	$ 2,389,333	$ 2,404,935
Loans acquired, not covered by FDIC loss share	398,967	515,644
Loans acquired, covered by FDIC loss share	121,524	146,653
Credit Cards [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	176,239	184,935
Credit Cards [Member] | Consumer Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	175,772	184,415
Credit Cards [Member] | Consumer Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	467	520
Student Loans [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	398	25,906
Student Loans [Member] | Consumer Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables		23,642
Student Loans [Member] | Consumer Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	398	2,264
Other Consumer [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	105,998	98,851
Other Consumer [Member] | Consumer Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	104,886	97,655
Other Consumer [Member] | Consumer Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	4	2
Other Consumer [Member] | Consumer Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	1,041	1,121
Other Consumer [Member] | Consumer Loans [Member] | Risk Rate 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	52	56
Other Consumer [Member] | Consumer Loans [Member] | Risk Rate 8 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	15	17
Construction Loans [Member] | Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	163,412	146,458
Construction Loans [Member] | Real Estate Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	159,825	142,213
Construction Loans [Member] | Real Estate Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	45	71
Construction Loans [Member] | Real Estate Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	3,542	4,174
Single Family Residential Loans [Member] | Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	417,187	392,285
Single Family Residential Loans [Member] | Real Estate Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	408,160	383,934
Single Family Residential Loans [Member] | Real Estate Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	1,641	1,412
Single Family Residential Loans [Member] | Real Estate Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	7,386	6,939
Other Commercial Real Estate Loans [Member] | Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	653,734	626,333
Other Commercial Real Estate Loans [Member] | Real Estate Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	629,094	600,045
Other Commercial Real Estate Loans [Member] | Real Estate Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	4,511	7,597
Other Commercial Real Estate Loans [Member] | Real Estate Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	20,129	18,691
Commercial [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	233,510	164,329
Commercial [Member] | Commercial Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	227,909	162,118
Commercial [Member] | Commercial Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	2,077	200
Commercial [Member] | Commercial Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	3,514	2,001
Commercial [Member] | Commercial Loans [Member] | Risk Rate 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	10	10
Agricultural Loans [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	111,567	98,886
Agricultural Loans [Member] | Commercial Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	111,242	98,761
Agricultural Loans [Member] | Commercial Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	325	125
Other Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	6,797	4,655
Other Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	6,797	4,655
Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	282,635	309,692
Consumer Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	280,658	305,712
Consumer Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	4	2
Consumer Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	1,906	3,905
Consumer Loans [Member] | Risk Rate 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	52	56
Consumer Loans [Member] | Risk Rate 8 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	15	17
Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	1,234,333	1,165,076
Real Estate Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	1,197,079	1,126,192
Real Estate Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	6,197	9,080
Real Estate Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	31,057	29,804
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	345,077	263,215
Commercial Loans [Member] | Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	339,151	260,879
Commercial Loans [Member] | Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	2,077	200
Commercial Loans [Member] | Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	3,839	2,126
Commercial Loans [Member] | Risk Rate 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	10	10
Risk Rate 1-4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	2,297,291	2,301,188
Loans acquired, not covered by FDIC loss share	352,082	457,097
Loans acquired, covered by FDIC loss share	121,524	146,653
Risk Rate 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	8,278	9,282
Risk Rate 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	82,687	94,382
Loans acquired, not covered by FDIC loss share	45,885	58,547
Risk Rate 7 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	1,062	66
Loans acquired, not covered by FDIC loss share	1,000
Risk Rate 8 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	$ 15	$ 17