Note 4 - Loans and Allowance for Loan Losses (Details) - Loan Portfolio by Categories (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Consumer:
Loans	$ 2,390,000	$ 2,400,000
Loans acquired, not covered by FDIC loss share (net of discount)	398,967	515,644
Loans acquired, covered by FDIC loss share (net of discount)	121,524	146,653
Credit Cards [Member]
Consumer:
Loans	176,239	184,935
Student Loans [Member]
Consumer:
Loans	398	25,906
Other Consumer [Member]
Consumer:
Loans	105,998	98,851
Consumer Loans [Member]
Consumer:
Loans	282,635	309,692
Construction Loans [Member]
Consumer:
Loans	163,412	146,458
Single Family Residential Loans [Member]
Consumer:
Loans	417,187	392,285
Other Commercial Real Estate Loans [Member]
Consumer:
Loans	653,734	626,333
Real Estate Loans [Member]
Consumer:
Loans	1,234,333	1,165,076
Other Commercial Loans [Member]
Consumer:
Loans	233,510	164,329
Agricultural Loans [Member]
Consumer:
Loans	111,567	98,886
Commercial Loans [Member]
Consumer:
Loans	345,077	263,215
Other Loans [Member]
Consumer:
Loans	6,797	4,655
Loans, excluding acquired loans [Member]
Consumer:
Loans	1,868,842	1,742,638
Loans, including acquired loans [Member]
Consumer:
Total loans before allowance for loan losses	$ 2,389,333	$ 2,404,935