Note 15 - Financial Instruments With Off-balance Sheet Risk - Contractual Amount of Financial Instruments with Off-balance Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Standby Letters of Credit [Member]
Commitments to extend credit, including unused lines of credit	$ 4,100	$ 10,500
Commitments to Extend Credit [Member]
Commitments to extend credit, including unused lines of credit	188,000	172,000
Fixed Rate [Member]
Commitments to extend credit, including unused lines of credit	73,653	63,683
Fixed Rate [Member] | Standby Letters of Credit [Member]
Commitments to extend credit, including unused lines of credit	2,284	2,495
Fixed Rate [Member] | Commitments to Extend Credit [Member]
Commitments to extend credit, including unused lines of credit	71,369	61,188
Variable Rate [Member]
Commitments to extend credit, including unused lines of credit	118,695	119,201
Variable Rate [Member] | Standby Letters of Credit [Member]
Commitments to extend credit, including unused lines of credit	1,769	7,999
Variable Rate [Member] | Commitments to Extend Credit [Member]
Commitments to extend credit, including unused lines of credit	$ 116,926	$ 111,202