Condensed Consolidating Financial Statements - Condensed Consolidating Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended							9 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Net sales	$ 390,865	$ 405,301	$ 406,413	$ 402,218	$ 412,852	$ 410,803	$ 417,469	$ 419,960	$ 1,604,797	$ 1,661,084	$ 1,802,415
Energy and related sales, net									6,141	5,664	7,927
Total revenues									1,610,938	1,666,748	1,810,342
Costs of products sold									1,392,335	1,463,783	1,575,188
Gross profit	$ 56,867	$ 61,170	$ 42,723	$ 57,843	$ 58,116	$ 32,833	$ 52,108	$ 59,908	218,603	202,965	235,154
Selling, general and administrative expenses									190,694	127,706	133,235
Losses (gains) on dispositions of plant, equipment and timberlands, net									216	(21,113)	(4,861)
Operating income									27,693	96,372	106,780
Other non-operating income (expense)
Interest expense									(15,822)	(17,464)	(18,921)
Interest income									206	283	159
Other, net									(1,271)	(615)	(635)
Total non-operating expense									(16,887)	(17,796)	(19,397)
Income before income taxes									10,806	78,576	87,383
Income tax provision (benefit)									(10,748)	14,001	18,137
Net income									21,554	64,575	69,246
Other comprehensive income (loss)									(14,120)	(35,616)	(79,513)
Comprehensive income (loss)									7,434	28,959	(10,267)
Adjustments/ Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									(69,645)	(78,026)	(75,917)
Total revenues									(69,645)	(78,026)	(75,917)
Costs of products sold									(69,645)	(78,026)	(75,917)
Other non-operating income (expense)
Interest expense									4,715	37,542	102,755
Interest income									(4,715)	(37,543)	(102,756)
Equity in earnings of subsidiaries									(119,354)	(86,683)	(33,325)
Total non-operating expense									(119,354)	(86,684)	(33,326)
Income before income taxes									(119,354)	(86,684)	(33,326)
Net income									(119,354)	(86,684)	(33,326)
Other comprehensive income (loss)									51,092	11,330	11,864
Comprehensive income (loss)									(68,262)	(75,354)	(21,462)
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									843,582	875,026	902,892
Energy and related sales, net									6,141	5,664	7,927
Total revenues									849,723	880,690	910,819
Costs of products sold									763,109	811,329	830,710
Gross profit									86,614	69,361	80,109
Selling, general and administrative expenses									133,387	71,751	67,086
Losses (gains) on dispositions of plant, equipment and timberlands, net									177	(19,720)	(3,545)
Operating income									(46,950)	17,330	16,568
Other non-operating income (expense)
Interest expense									(17,436)	(18,147)	(19,105)
Interest income									687	673	638
Equity in earnings of subsidiaries									61,007	61,946	67,590
Other, net									(2,312)	(3,389)	(1,366)
Total non-operating expense									41,946	41,083	47,757
Income before income taxes									(5,004)	58,413	64,325
Income tax provision (benefit)									(26,558)	(6,162)	(4,921)
Net income									21,554	64,575	69,246
Other comprehensive income (loss)									(14,120)	(35,616)	(79,513)
Comprehensive income (loss)									7,434	28,959	(10,267)
Guarantors [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									75,000	84,704	78,077
Total revenues									75,000	84,704	78,077
Costs of products sold									70,991	80,455	74,414
Gross profit									4,009	4,249	3,663
Selling, general and administrative expenses									(156)	821	1,765
Losses (gains) on dispositions of plant, equipment and timberlands, net										(1,183)	(1,316)
Operating income									4,165	4,611	3,214
Other non-operating income (expense)
Interest expense									(41)
Interest income									4,177	37,127	102,241
Equity in earnings of subsidiaries									58,347	24,737	(34,265)
Other, net									(3,966)	(1,471)	317
Total non-operating expense									58,517	60,393	68,293
Income before income taxes									62,682	65,004	71,507
Income tax provision (benefit)									1,675	2,922	3,916
Net income									61,007	62,082	67,591
Other comprehensive income (loss)									(25,916)	(41,010)	(40,704)
Comprehensive income (loss)									35,091	21,072	26,887
Non Guarantors [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									755,860	779,380	897,363
Total revenues									755,860	779,380	897,363
Costs of products sold									627,880	650,025	745,981
Gross profit									127,980	129,355	151,382
Selling, general and administrative expenses									57,463	55,134	64,384
Losses (gains) on dispositions of plant, equipment and timberlands, net									39	(210)
Operating income									70,478	74,431	86,998
Other non-operating income (expense)
Interest expense									(3,060)	(36,859)	(102,571)
Interest income									57	26	36
Other, net									5,007	4,245	414
Total non-operating expense									2,004	(32,588)	(102,121)
Income before income taxes									72,482	41,843	(15,123)
Income tax provision (benefit)									14,135	17,241	19,142
Net income									58,347	24,602	(34,265)
Other comprehensive income (loss)									(25,176)	29,680	28,840
Comprehensive income (loss)									$ 33,171	$ 54,282	$ (5,425)