Note 8 - Components of Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) (Parentheticals) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	$ 1,454	$ 2,170
Reclassification adjustment for gain included in net income, taxes		(18)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	0	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	$ 1,454	2,170
Reclassification adjustment for gain included in net income, taxes		$ (18)