Note 4 - Securities - Expected Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available-for-sale securities, amortized cost, one year or less	$ 4,946
Available-for-sale securities, fair value, one year or less	4,991
Held-to-maturity securities, amortized cost, One year or less
Held-to-maturity securities, fair value, one year or less
Available-for-sale securities, amortized cost, one year through five years	62,910
Available-for-sale securities, fair value, one year through five years	63,417
Held-to-maturity securities, amortized cost, one year through five years	4,575
Held-to-maturity securities, fair value, one year through five years	4,830
Available-for-sale securities, amortized cost, five years through ten years	33,575
Available-for-sale securities, fair value, five years through ten years	34,693
Held-to-maturity securities, amortized cost, five years through ten years	13,435
Held-to-maturity securities, fair value, five years through ten years	14,087
Available-for-sale securities, amortized cost, after ten years	52,720
Available-for-sale securities, fair value, after ten years	53,339
Held-to-maturity securities, amortized cost, after ten years	13,761
Held-to-maturity securities, fair value, after ten years	14,471
Available-for-sale securities, amortized cost, total	154,151
Available-for-sale securities, fair value, total	156,440	$ 159,030
Held-to-maturity securities, amortized cost, total	31,771
Held-to-maturity securities, fair value, total	$ 33,388