Note 5 - Accumulated Other Comprehensive Loss (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	$ (412)	$ 1,829
Other Comprehensive Income (Loss) before Reclassifications, Tax	(139)	724
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	941	1,228
Reclassification from AOCI, Current Period, Tax	346	452
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	876	(1,574)
Other Comprehensive Income (Loss) before Reclassifications, Tax	$ 341	$ (609)