Supplementary Balance Sheet Detail (Tables)

12 Months Ended

Dec. 31, 2019

Balance Sheet Related Disclosures [Abstract]

Schedule Of Amounts Recognized In Balance Sheet

The following tables present supplementary balance sheet details:

	As of December 31, 2019		As of December 31, 2018
	(Dollars in thousands)
Inventories:
Raw materials and supplies	$	104,820	$	99,935
Work in process	137,230		125,767
Finished goods	71,598		68,015
	$	313,648	$	293,717
Prepaid expenses and other current assets:
Prepaid expenses	$	9,986	$	10,720
Value added tax and other indirect taxes receivable	13,890		19,242
Spare parts inventory	12,738		11,507
Other current assets	4,332		4,699
	$	40,946	$	46,168
Property, plant and equipment:
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
	$	733,417	$	688,842
Other accrued liabilities:
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
	$	48,335	$	50,452
Other long term obligations:
Postretirement benefits	$	16,528	$	16,192
Pension and related benefits	37,431		33,718
Other	18,603		22,609
	$	72,562	$	72,519

Schedule Of Analysis Of The Allowance For Doubtful Accounts

The following table presents an analysis of the allowance for doubtful accounts:

	2019			2018			2017
Balance at beginning of year	$	1,129		$	1,097		$	326
Additions	4,636			122			771
Deductions	(291		)	(90		)	—
Balance at end of year	$	5,474		$	1,129		$	1,097