Note 9 - Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Beginning balance	$ (65,520)	$ (55,449)
Other comprehensive income before reclassifications	2,468	7,095
Amounts reclassified from accumulated other comprehensive loss	244	202
Net current-period other comprehensive income	2,712	7,297
Ending balance	(62,808)	(48,152)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Beginning balance	(34,290)	(25,880)
Other comprehensive income before reclassifications	2,468	7,095
Amounts reclassified from accumulated other comprehensive loss
Net current-period other comprehensive income	2,468	7,095
Ending balance	(31,822)	(18,785)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Beginning balance	(31,230)	(29,569)
Other comprehensive income before reclassifications
Amounts reclassified from accumulated other comprehensive loss	244	202
Net current-period other comprehensive income	244	202
Ending balance	$ (30,986)	$ (29,367)