Note 7 - Fair Value Measurements (Details) - Fair Value of Financial Assets and Liabililties Measure on Recurring Basis - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Assets:
Available-for-sale securities	$ 50,686	$ 54,603
US Government Agencies Debt Securities [Member]
Assets:
Available-for-sale securities	24,583	26,965
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Assets:
Available-for-sale securities	8,870	9,739
US States and Political Subdivisions Debt Securities [Member]
Assets:
Available-for-sale securities	17,233	17,899
Fair Value, Inputs, Level 2 [Member]
Assets:
Available-for-sale securities	50,686	54,603
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member]
Assets:
Available-for-sale securities	24,583	26,965
Fair Value, Inputs, Level 2 [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Assets:
Available-for-sale securities	8,870	9,739
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Assets:
Available-for-sale securities	$ 17,233	$ 17,899