Income Taxes (Deferred Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Deferred employee benefits	$ 43,583	$ 46,539
Inventories	2,210	5,528
Tax loss and credit carryforwards	20,736	20,813
Accrued liabilities and other items	11,046	7,031
Total deferred tax assets	77,575	79,911
Deferred tax liabilities:
Property, plant and equipment	(11,584)	(10,756)
Intangibles	(39,832)	(40,258)
Other items	(216)	(4,020)
Deferred Tax Liabilities, Gross	51,632	55,034
Net Deferred Tax Assets Before Valuation Allowance	25,943	24,877
Valuation allowance	(8,533)	(5,298)
Net deferred tax assets after valuation allowance	17,410	19,579
Change in valuation allowance	3,200
Pre-tax income (loss) from foreign operations	26,700	$ (700)	$ 5,000
Delamac
Deferred tax liabilities:
Net deferred tax assets	$ 1,300