CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities:
Net income	$ 34,785	$ 76,079
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	48,562	37,176
Equity compensation expense	10,317	9,294
Deferred income taxes	(9,987)	(5,565)
Equity in undistributed income of unconsolidated joint ventures	(3,177)	(4,077)
Dividends received from unconsolidated joint ventures	7,075	5,375
Pension settlement benefits	(63)	0
Pension and other postretirement benefits	(149)	(503)
Asbestos-related charges	0	67
Loss on sale or disposal of property, plant and equipment	49	278
Impairment charges	386	1,537
Provision (benefit) for doubtful accounts	(63)	16
Changes in assets and liabilities:
Accounts receivable	(14,702)	3,668
Contract assets	394	(1,342)
Inventories	25,008	(7,788)
Pension and postretirement benefit contributions	(248)	(16)
Other current assets	1,876	641
Accounts payable and other accrued expenses	5,236	(2,552)
Other, net	8,374	3,384
Net cash provided by operating activities	113,673	115,672
Investing Activities:
Capital expenditures	(28,944)	(38,827)
Proceeds from the sale of property, plant and equipment, net	0	9
Return of capital from unconsolidated joint ventures	0	2,625
Net cash used in investing activities	(28,944)	(36,193)
Financing Activities:
Proceeds from borrowings under revolving credit facility	150,000	0
Repayment of debt principal and finance lease obligations	(213,299)	(98,294)
Payments of taxes related to net share settlement of equity awards	(5,107)	(7,309)
Proceeds from the exercise of stock options, net	0	344
Proceeds from issuance of shares to employee stock purchase plan	1,373	1,249
Net cash provided by (used in) financing activities	(67,033)	(104,010)
Effect of exchange rate fluctuations on cash	1,578	(2,460)
Net increase (decrease) in cash and cash equivalents	19,274	(26,991)
Cash and cash equivalents at beginning of period	166,849	167,738
Cash and cash equivalents at end of period	186,123	140,747
Supplemental Disclosures:
Accrued capital additions	1,493	1,999
Interest, net of amounts capitalized	4,301	6,449
Income taxes	$ 21,645	$ 16,018