Note 4 - Loans and Allowance for Loan Losses (Details) - Troubled Debt Restructurings, Excluding Loans Acquired, Segregated by Class of Loans (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Real estate:
Number	3	1
Accruing TDR Loans [Member] \| Construction Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		1
Balance		988
Accruing TDR Loans [Member] \| Single Family Residential Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	2	4
Balance	393	862
Accruing TDR Loans [Member] \| Other Commercial Real Estate Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	3	9
Balance	1,840	6,974
Accruing TDR Loans [Member] \| Real Estate Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	5	14
Balance	2,233	8,824
Accruing TDR Loans [Member] \| Other Commercial Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		1
Balance		39
Accruing TDR Loans [Member] \| Agricultural Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		1
Balance		635
Accruing TDR Loans [Member] \| Commercial Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		2
Balance		674
Accruing TDR Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	5	16
Balance	2,233	9,498
Nonaccrual TDR Loans [Member] \| Construction Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	1
Balance	391
Nonaccrual TDR Loans [Member] \| Single Family Residential Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	1
Balance	3
Nonaccrual TDR Loans [Member] \| Other Commercial Real Estate Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	1	1
Balance	614	608
Nonaccrual TDR Loans [Member] \| Real Estate Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	3	1
Balance	1,008	608
Nonaccrual TDR Loans [Member] \| Other Commercial Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		1
Balance		60
Nonaccrual TDR Loans [Member] \| Agricultural Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		0
Balance		0
Nonaccrual TDR Loans [Member] \| Commercial Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		1
Balance		60
Nonaccrual TDR Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	3	2
Balance	1,008	668
Construction Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	1	1
Balance	391	988
Single Family Residential Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	3	4
Balance	396	862
Other Commercial Real Estate Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	4	10
Balance	2,454	7,582
Real Estate Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number	8	15
Balance	3,241	9,432
Other Commercial Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		2
Balance		99
Agricultural Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		1
Balance		635
Commercial Loans [Member] \| Loans, excluding acquired loans [Member]
Real estate:
Number		3
Balance		734
Loans, excluding acquired loans [Member]
Real estate:
Number	8	18
Balance	3,241	10,166

Note 4 - Loans and Allowance for Loan Losses (Details) - Troubled Debt Restructurings, Excluding Loans Acquired, Segregated by Class of Loans (USD $)
In Thousands, unless otherwise specified