Condensed Consolidating Financial Statements - Condensed Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided (used) by Operating activities	$ 38	$ 28,764
Investing activities
Expenditures for purchases of plant, equipment and timberlands	(36,944)	(71,047)
Proceeds from disposals of plant, equipment and timberlands, net	2,384	83
Other	(68)
Net cash used by investing activities	(34,628)	(70,964)
Financing activities
Net borrowings (repayments) of long-term debt	41,013	63,708
Payment of dividends to shareholders	(11,368)	(11,130)
Proceeds from government grants	125
Payments related to share-based compensation awards and other	(980)	(112)
Net cash provided by financing activities	28,790	52,466
Effect of exchange rate on cash	(3,230)	3,732
Net increase (decrease) in cash and cash equivalents	(9,030)	13,998
Cash and cash equivalents at the beginning of period	116,219	55,444
Cash and cash equivalents at the end of period	107,189	69,442
Adjustments/ Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided (used) by Operating activities	(20,000)	(685)
Investing activities
Repayments from intercompany loans		(12,000)
Advances of intercompany loans	3,445	12,550
Intercompany capital contributed	315	400
Intercompany capital returned	(20,000)
Net cash used by investing activities	(16,240)	950
Financing activities
Repayments of intercompany loans		12,000
Borrowings of intercompany loans	(3,445)	(12,550)
Intercompany capital received	(315)	(400)
Intercompany capital returned	20,000
Payment of intercompany dividend	20,000	685
Net cash provided by financing activities	36,240	(265)
Parent Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided (used) by Operating activities	(4,089)	(12,072)
Investing activities
Expenditures for purchases of plant, equipment and timberlands	(13,414)	(40,739)
Proceeds from disposals of plant, equipment and timberlands, net	598	8
Other	(68)
Net cash used by investing activities	(12,884)	(40,731)
Financing activities
Net borrowings (repayments) of long-term debt	25,660	55,000
Payment of dividends to shareholders	(11,368)	(11,130)
Borrowings of intercompany loans	3,445	12,550
Proceeds from government grants	125
Payments related to share-based compensation awards and other	(980)	(112)
Net cash provided by financing activities	16,882	56,308
Net increase (decrease) in cash and cash equivalents	(91)	3,505
Cash and cash equivalents at the beginning of period	1,292	5,082
Cash and cash equivalents at the end of period	1,201	8,587
Guarantors [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided (used) by Operating activities	(114)	(1,085)
Investing activities
Expenditures for purchases of plant, equipment and timberlands	(12,902)	(21,421)
Proceeds from disposals of plant, equipment and timberlands, net	1,785	75
Repayments from intercompany loans		12,000
Advances of intercompany loans	(3,445)	(12,550)
Intercompany capital contributed	(315)	(400)
Intercompany capital returned	20,000
Net cash used by investing activities	5,123	(22,296)
Financing activities
Net borrowings (repayments) of long-term debt	16,000	25,000
Payment of intercompany dividend	(20,000)
Net cash provided by financing activities	(4,000)	25,000
Net increase (decrease) in cash and cash equivalents	1,009	1,619
Cash and cash equivalents at the beginning of period	720	1,461
Cash and cash equivalents at the end of period	1,729	3,080
Non Guarantors [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided (used) by Operating activities	24,241	42,606
Investing activities
Expenditures for purchases of plant, equipment and timberlands	(10,628)	(8,887)
Proceeds from disposals of plant, equipment and timberlands, net	1
Net cash used by investing activities	(10,627)	(8,887)
Financing activities
Net borrowings (repayments) of long-term debt	(647)	(16,292)
Repayments of intercompany loans		(12,000)
Intercompany capital received	315	400
Intercompany capital returned	(20,000)
Payment of intercompany dividend		(685)
Net cash provided by financing activities	(20,332)	(28,577)
Effect of exchange rate on cash	(3,230)	3,732
Net increase (decrease) in cash and cash equivalents	(9,948)	8,874
Cash and cash equivalents at the beginning of period	114,207	48,901
Cash and cash equivalents at the end of period	$ 104,259	$ 57,775