Note 2 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Inputs, Level 2 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Assets:
Assets measured on a recurring basis	$ 7,994	$ 8,965
Fair Value, Inputs, Level 2 [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Assets:
Assets measured on a recurring basis	79,985	82,686
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Nonowner Occupied [Member] | Impaired Loans [Member]
Commercial real estate:
Assets measured on a nonrecurring basis	2,375	2,473
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Construction Loans [Member] | Other Real Estate Owned [Member]
Commercial real estate:
Assets measured on a nonrecurring basis	1,147	1,147
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Commercial real estate:
Assets measured on a nonrecurring basis	$ 3,905	$ 3,779