Note 13 - Condensed Financial Statements of Parent Company - Condensed Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income
Interest on securities – nontaxable	$ 5,123	$ 5,438	$ 5,826
Other income	1,289	1,295	1,037
Expenses
Income before income tax benefit and equity in undistributed net income of subsidiaries	18,894	20,573	22,092
Applicable income tax benefit	3,952	4,740	5,178
Net income	14,942	15,833	16,914
Parent Company [Member]
Income
Dividends from subsidiaries	9,421	7,930	7,853
Interest on securities – taxable	2	3	2
Interest on securities – nontaxable	0	0	1
Other income	987	1,208	1,250
Total income	10,410	9,141	9,106
Expenses
Other expenses	1,992	2,051	2,046
Income before income tax benefit and equity in undistributed net income of subsidiaries	8,418	7,090	7,060
Applicable income tax benefit	628	210	136
Income before equity in undistributed net income of subsidiaries	9,046	7,300	7,196
Equity in undistributed net income of subsidiaries	5,896	8,533	9,718
Net income	$ 14,942	$ 15,833	$ 16,914