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	3 Months Ended	9 Months Ended		12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended				9 Months Ended	12 Months Ended	9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended				9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended				9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013 Accruing TDR Loans [Member] Construction Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Accruing TDR Loans [Member] Single Family Residential Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Single Family Residential Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Accruing TDR Loans [Member] Other Commercial Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Other Commercial Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Accruing TDR Loans [Member] Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Other Commercial Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Agricultural Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Commercial Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Accruing TDR Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Accruing TDR Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Nonaccrual TDR Loans [Member] Construction Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Nonaccrual TDR Loans [Member] Single Family Residential Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Nonaccrual TDR Loans [Member] Other Commercial Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Nonaccrual TDR Loans [Member] Other Commercial Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Nonaccrual TDR Loans [Member] Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Nonaccrual TDR Loans [Member] Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Nonaccrual TDR Loans [Member] Other Commercial Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Nonaccrual TDR Loans [Member] Agricultural Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Nonaccrual TDR Loans [Member] Commercial Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Nonaccrual TDR Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Nonaccrual TDR Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Construction Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Construction Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Single Family Residential Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Single Family Residential Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Other Commercial Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Other Commercial Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Real Estate Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Other Commercial Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Agricultural Loans [Member] Loans, excluding acquired loans [Member]	Dec. 31, 2013 Commercial Loans [Member] Loans, excluding acquired loans [Member]	Sep. 30, 2014 Loans, excluding acquired loans [Member]	Dec. 31, 2013 Loans, excluding acquired loans [Member]
Real estate:
Number	0	2	1	1	2	4	3	9	5	14	1	1	2	5	16	1	1	1	1	3	1	1	0	1	3	2	1	1	3	4	4	10	8	15	2	1	3	8	18
Balance				$ 988	$ 395	$ 862	$ 1,839	$ 6,974	$ 2,234	$ 8,824	$ 39	$ 635	$ 674	$ 2,234	$ 9,498	$ 433	$ 3	$ 623	$ 608	$ 1,059	$ 608	$ 60	$ 0	$ 60	$ 1,059	$ 668	$ 433	$ 988	$ 398	$ 862	$ 2,462	$ 7,582	$ 3,293	$ 9,432	$ 99	$ 635	$ 734	$ 3,293	$ 10,166