Supplementary Balance Sheet Detail (Schedule Of Amounts Recognized In Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Raw materials and supplies	$ 104,820	$ 99,935
Work in process	137,230	125,767
Finished goods	71,598	68,015
Inventories	313,648	293,717
Prepaid expenses	9,986	10,720
Value added tax and other indirect taxes receivable	13,890	19,242
Other Inventories, Spare Parts, Gross	12,738	11,507
Other current assets	4,332	4,699
Prepaid Expense and Other Assets, Current	40,946	46,168
Land and improvements	46,548	45,947
Buildings	71,784	68,680
Machinery and equipment and other	567,715	532,084
Construction in progress	47,370	42,131
Property, plant and equipment	733,417	688,842
Payrolls (including incentive programs)	11,801	17,284
Employee benefits	7,416	6,977
Deferred Revenue	11,776	5,380
Other	17,342	20,811
Accrued liabilities, net	48,335	50,452
Postretirement benefits	16,528	16,192
Pension and related benefits	37,431	33,718
Other	18,603	22,609
Other long - term obligations	$ 72,562	$ 72,519