Note 4 - Loans and Allowance for Loan Losses - Nonaccrual Loans, Excluding Loans Acquired, Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Loans in nonaccrual status	$ 39,104	$ 17,714
Consumer Portfolio Segment [Member]
Loans in nonaccrual status	2,166	654
Consumer Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans in nonaccrual status	373	212
Consumer Portfolio Segment [Member] | Other Loans [Member]
Loans in nonaccrual status	1,793	442
Commercial Real Estate Portfolio Segment [Member]
Loans in nonaccrual status	27,935	14,828
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans in nonaccrual status	3,411	4,955
Commercial Real Estate Portfolio Segment [Member] | Single Family Residential Loans [Member]
Loans in nonaccrual status	12,139	5,453
Commercial Real Estate Portfolio Segment [Member] | Other Commercial Loans [Member]
Loans in nonaccrual status	12,385	4,420
Commercial Portfolio Segment [Member]
Loans in nonaccrual status	9,003	2,232
Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans in nonaccrual status	7,765	1,968
Commercial Portfolio Segment [Member] | Agricultural Loans [Member]
Loans in nonaccrual status	$ 1,238	$ 264