Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net income (loss)	$ 21,298	$ (21,541)	$ (177,604)
(Income) loss from discontinued operations, net of tax benefits	(515)	(3,670)	177,156
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation, depletion and amortization	56,600	50,820	47,525
Amortization of debt issue costs and original issue discount	590	1,672	1,159
Pension settlement charge	6,154	75,326
Asset impairment charge	900
Deferred income tax benefit	(2,071)	(22,971)	(7,704)
Gains on dispositions of plant, equipment and timberlands, net	(1,332)	(2,060)	(3,256)
Share-based compensation	5,655	3,583	6,288
Change in operating assets and liabilities
Accounts receivable	9,563	(5,473)	(621)
Inventories	6,860	(17,387)	(32,138)
Prepaid and other current assets	1,679	(2,833)	(3,372)
Accounts payable	(7,234)	10,337	13,774
Accruals and other current liabilities	12,143	(19,536)	(23,984)
Pension assets received		53,401
Other	4,857	3,167	(3,175)
Net cash provided (used) by operating activities	108,993	102,835	(5,952)
Investing activities
Expenditures for purchases of plant, equipment and timberlands	(28,136)	(27,765)	(42,129)
Proceeds from disposals of plant, equipment and timberlands, net	1,413	2,198	3,462
Acquisition, net of cash acquired		(1,383)	(178,905)
Other investing	(50)	(163)	(68)
Net cash used by investing activities	(26,773)	(27,113)	(217,640)
Financing activities
Repayments of note offerings		(250,000)
Net repayments under revolving credit facility	(53,392)	(28,062)	(55,446)
Payments of borrowing costs	(39)	(2,204)
Proceeds from term loans		248,644
Repayment of term loans	(23,246)	(16,660)	(11,069)
Payments of dividends	(23,492)	(22,936)	(22,760)
Proceeds from government grants	358
Payments related to share-based compensation awards and other	(495)	(1,556)	(2,151)
Net cash used by financing activities	(100,306)	(72,774)	(91,426)
Effect of exchange rate changes on cash	5,163	(269)	(5,564)
Net increase (decrease) in cash, cash equivalents and restricted cash	(12,923)	2,679	(320,582)
Change in cash and cash equivalents from discontinued operations	(1,613)	(19,163)	347,048
Cash, cash equivalents and restricted cash at the beginning of period	126,201	142,685	116,219
Cash, cash equivalents and restricted cash at the end of period	111,665	126,201	142,685
Less: restricted cash in Prepaid and other current assets	(2,000)
Less: restricted cash in Other assets	(10,084)
Cash and cash equivalents at the end of period	99,581	126,201	142,685
Cash paid (refunded) for:
Interest, net of amounts capitalized	6,180	10,208	15,760
Income taxes, net	$ (9,993)	$ 14,242	$ 15,171