Note 5 - Accumulated Other Comprehensive Loss (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	$ (211)	$ (800)
Other Comprehensive Income (Loss) before Reclassifications, Tax, Total	(55)	(209)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	802	883
Reclassification from AOCI, Current Period, Tax, Total	(209)	(230)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	3,951	6,096
Other Comprehensive Income (Loss) before Reclassifications, Tax, Total	$ 1,027	$ 2,384