Note 8 - Components of Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Loss) (Details) (Parentheticals) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Unrealized holding gain on securities transferred from held to maturity to available for sale, tax	$ 237
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	2,149	$ (1,378)
Unrealized holding gain on securities transferred from held to maturity to available for sale, tax		237
Reclassification adjustment for gain included in net income, taxes	(38)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	0	0
Unrealized holding gain on securities transferred from held to maturity to available for sale, tax		0
Reclassification adjustment for gain included in net income, taxes	0
AOCI Attributable to Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	2,149	(1,378)
Unrealized holding gain on securities transferred from held to maturity to available for sale, tax		$ 237
Reclassification adjustment for gain included in net income, taxes	$ (38)