Note 11 - Fair Value of Financial Instruments and Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Impaired Loans [Member]
Nonrecurring
Assets, fair value, nonrecurring	$ 7,210	$ 7,778
Other Real Estate [Member]
Nonrecurring
Assets, fair value, nonrecurring	4,974	6,128
Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	271,611	274,594
US Government Agencies Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	267,380	271,064
US States and Political Subdivisions Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	4,231	3,530
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Nonrecurring
Assets, fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | Other Real Estate [Member]
Nonrecurring
Assets, fair value, nonrecurring	0	0
Fair Value, Inputs, Level 1 [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	0	0
Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	0	0
Fair Value, Inputs, Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	0	0
Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Nonrecurring
Assets, fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Other Real Estate [Member]
Nonrecurring
Assets, fair value, nonrecurring	0	0
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	270,668	273,646
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	267,380	271,064
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	3,288	2,582
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Nonrecurring
Assets, fair value, nonrecurring	7,210	7,778
Fair Value, Inputs, Level 3 [Member] | Other Real Estate [Member]
Nonrecurring
Assets, fair value, nonrecurring	4,974	6,128
Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	943	948
Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	0	0
Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member] | Available-for-sale Securities [Member]
Recurring
Assets, fair value, recurring	$ 943	$ 948