Note 8 - Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Income (Loss) Reported in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Balance	$ 293,132	$ 325,495
Balance	296,947	332,548
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(8,243)	(5,321)
Reclassification adjustments
Current period charge (benefit)	(185)	189
Income tax benefit (charge)	33
Balance	(8,395)	(5,132)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(15,180)	(7,188)
Reclassification adjustments	398	681
Current period charge (benefit)
Income tax benefit (charge)	(82)	(171)
Balance	(14,864)	(6,678)
AOCI Attributable to Parent [Member]
Balance	(23,423)	(12,509)
Reclassification adjustments	398	681
Current period charge (benefit)	(185)	189
Income tax benefit (charge)	(49)	(171)
Balance	$ (23,259)	$ (11,810)