Note 8 - Accumulated Other Comprehensive Income (Loss) - Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Total before income tax		$ (13,652)	$ (7,957)	$ (38,894)	$ (27,084)
Income tax		2,951	2,255	8,403	8,469
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Recognized actuarial loss	[1]	285	267	896	879
Total before income tax		405	715	3,632	4,720
Income tax		(97)	(243)	(893)	(1,692)
Net of income tax		308	472	2,739	3,028
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Cost of Sales [Member]
Settlement loss	[2]	$ 120	$ 448	$ 2,736	$ 3,841

[1] The recognized actuarial loss is included in the computation of net periodic benefit cost. See Note 7 for additional details.

[2] The settlement loss is included in other income (expense), net on the consolidated statements of income.