CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net income	$ 116,629	$ 108,133	$ 49,990
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	45,879	43,284	71,425
Equity compensation expense	11,796	16,994	13,532
Deferred income taxes	(20,556)	(3,195)	(13,406)
Equity in undistributed income of unconsolidated joint ventures	(4,437)	(7,032)	(4,877)
Dividends received from unconsolidated joint ventures	4,677	4,965	7,075
Pension settlement charges	0	534	(63)
Pension and other postretirement benefits	21	(471)	(160)
Asbestos-related provision (benefit)	30	(220)	(682)
Loss (gain) on sale or disposal of property, plant and equipment	460	(880)	41
Impairment charges	65,085	455	639
UTIS fire fixed asset and inventory write-offs	200	1,947	0
Provision (benefit) for credit losses	208	(279)	223
Changes in assets and liabilities:
Accounts receivable	(32,251)	(26,197)	(8,934)
Proceeds from insurance/government subsidies related to operations	1,153	400	0
Contract assets	(3,895)	(10,035)	(4,120)
Inventories	(51,610)	(34,413)	34,687
Pension and postretirement benefit contributions	(94)	(160)	(253)
Other current assets	(6,295)	1,723	(217)
Accounts payable and other accrued expenses	(8,700)	36,688	10,084
Other, net	11,161	(7,878)	10,072
Net cash provided by operating activities	129,461	124,363	165,056
Investing Activities:
Acquisition of business, net of cash received	(3,581)	(168,204)	0
Capital expenditures	(116,788)	(71,125)	(40,385)
Proceeds from the sale of property, plant and equipment, net		714	0
Proceeds from insurance claims	7,252	0	0
Net cash used in investing activities	(113,117)	(238,615)	(40,385)
Financing Activities:
Proceeds from borrowings under revolving credit facility	100,000	190,000	150,000
Line of credit issuance costs	0	0	(1,862)
Repayment of debt principal and finance lease obligations	(75,271)	(29,624)	(248,330)
Payments of taxes related to net share settlement of equity awards	(10,783)	(2,881)	(5,357)
Proceeds from issuance of shares to employee stock purchase plan	950	1,562	1,360
Share repurchases	(25,000)	0	0
Net cash (used in) provided by financing activities	(10,104)	159,057	(104,189)
Effect of exchange rate fluctuations on cash	(2,686)	(4,294)	4,454
Net increase (decrease) in cash and cash equivalents	3,554	40,511	24,936
Cash and cash equivalents at beginning of period	232,296	191,785	166,849
Cash and cash equivalents at end of period	235,850	232,296	191,785
Supplemental Disclosures:
Accrued capital additions	6,675	10,903	715
Cash paid during the year for:
Interest, net of amounts capitalized	9,701	2,402	7,251
Income taxes	$ 60,772	$ 33,788	$ 29,983