Note 4 - Loans and Allowance for Loan Losses (Details) - Loan portfolio by categories: (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Consumer:
Loans acquired, covered by FDIC loss share (net of discount)	$ 163,736	$ 210,842
Loans acquired, not covered by FDIC loss share (net of discount)	63,500	82,764
Credit Cards [Member]
Consumer:
Loans	173,536	185,536
Student Loans [Member]
Consumer:
Loans	30,106	34,145
Other Consumer [Member]
Consumer:
Loans	103,765	105,319
Consumer Loans [Member]
Consumer:
Loans	307,407	325,000
Construction Loans [Member]
Consumer:
Loans	142,902	138,132
Single Family Residential Loans [Member]
Consumer:
Loans	364,239	356,907
Other Commercial Real Estate Loans [Member]
Consumer:
Loans	572,110	568,166
Real Estate Loans [Member]
Consumer:
Loans	1,079,251	1,063,205
Other Commercial Loans [Member]
Consumer:
Loans	152,122	141,336
Agricultural Loans [Member]
Consumer:
Loans	107,113	93,805
Commercial Loans [Member]
Consumer:
Loans	259,235	235,141
Other Loans [Member]
Consumer:
Loans	4,502	5,167
Loans, excluding acquired loans [Member]
Consumer:
Loans	1,650,395	1,628,513
Loans, including acquired loans [Member]
Consumer:
Total loans before allowance for loan losses	$ 1,877,631	$ 1,922,119