Guarantor Financial Statements (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Consolidated Statements of Income
Net sales	$ 404,354,000	$ 416,493,000	$ 1,186,399,000	$ 1,211,249,000
Energy and related sales, net	1,867,000	2,840,000	5,358,000	7,887,000
Total revenues	406,221,000	419,333,000	1,191,757,000	1,219,136,000
Costs of products sold	347,029,000	364,417,000	1,030,717,000	1,066,553,000
Gross profit	59,192,000	54,916,000	161,040,000	152,583,000
Selling, general and administrative expenses	29,380,000	31,430,000	89,460,000	94,520,000
Gains on dispositions of plant, equipment and timberlands, net	(1,473,000)	(698,000)	(8,471,000)	(3,902,000)
Operating income	31,285,000	24,184,000	80,051,000	61,965,000
Other non-operating income (expense)
Interest expense	(4,152,000)	(6,456,000)	(12,580,000)	(19,377,000)
Other, net	(4,000)	(137,000)	295,000	(405,000)
Total other non-operating income (expense)	(4,050,000)	(6,459,000)	(11,953,000)	(19,291,000)
Income (loss) before income taxes	27,235,000	17,725,000	68,098,000	42,674,000
Income tax provision (benefit)	7,136,000	4,699,000	15,689,000	9,721,000
Net income (loss)	20,099,000	13,026,000	52,409,000	32,953,000
Other comprehensive income (loss)	11,566,000	(14,236,000)	12,598,000	8,723,000
Comprehensive income	31,665,000	(1,210,000)	65,007,000	41,676,000
Parent Company [Member]
Condensed Consolidated Statements of Income
Net sales	232,620,000	225,410,000	670,536,000	662,572,000
Energy and related sales, net	1,867,000	2,840,000	5,358,000	7,887,000
Total revenues	234,487,000	228,250,000	675,894,000	670,459,000
Costs of products sold	203,084,000	201,649,000	596,508,000	601,185,000
Gross profit	31,403,000	26,601,000	79,386,000	69,274,000
Selling, general and administrative expenses	16,842,000	17,661,000	51,570,000	53,671,000
Gains on dispositions of plant, equipment and timberlands, net	16,000	(276,000)	(506,000)	(318,000)
Operating income	14,545,000	9,216,000	28,322,000	15,921,000
Other non-operating income (expense)
Interest expense	(4,917,000)	(6,625,000)	(14,704,000)	(16,563,000)
Other, net	12,016,000	10,935,000	3,681,000	34,120,000
Total other non-operating income (expense)	7,099,000	4,310,000	22,113,000	17,557,000
Income (loss) before income taxes	21,644,000	13,526,000	50,435,000	33,478,000
Income tax provision (benefit)	1,545,000	500,000	(1,974,000)	525,000
Net income (loss)	20,099,000	13,026,000	52,409,000	32,953,000
Other comprehensive income (loss)	11,566,000	(14,236,000)	12,598,000	8,723,000
Comprehensive income	31,665,000	(1,210,000)	65,007,000	41,676,000
Guarantors [Member]
Condensed Consolidated Statements of Income
Net sales	13,936,000	13,060,000	41,307,000	37,878,000
Total revenues	13,936,000	13,060,000	41,307,000	37,878,000
Costs of products sold	12,472,000	11,949,000	37,524,000	34,691,000
Gross profit	1,464,000	1,111,000	3,783,000	3,187,000
Selling, general and administrative expenses	880,000	646,000	2,220,000	1,893,000
Gains on dispositions of plant, equipment and timberlands, net	(1,489,000)	(417,000)	(7,940,000)	(3,575,000)
Operating income	2,073,000	882,000	9,503,000	4,869,000
Other non-operating income (expense)
Interest expense	1,779,000	2,032,000	5,121,000	5,905,000
Other, net	269,000	(134,000)	642,000	(13,000)
Total other non-operating income (expense)	2,048,000	1,898,000	5,763,000	5,892,000
Income (loss) before income taxes	4,121,000	2,780,000	15,266,000	10,761,000
Income tax provision (benefit)	1,637,000	979,000	6,523,000	4,111,000
Net income (loss)	2,484,000	1,801,000	8,743,000	6,650,000
Other comprehensive income (loss)	3,923,000	(8,284,000)	1,815,000	105,000
Comprehensive income	6,407,000	(6,483,000)	10,558,000	6,755,000
Non Guarantors [Member]
Condensed Consolidated Statements of Income
Net sales	171,734,000	191,083,000	515,874,000	548,677,000
Total revenues	171,734,000	191,083,000	515,874,000	548,677,000
Costs of products sold	145,377,000	163,900,000	437,945,000	468,756,000
Gross profit	26,357,000	27,183,000	77,929,000	79,921,000
Selling, general and administrative expenses	11,658,000	13,123,000	35,670,000	38,956,000
Gains on dispositions of plant, equipment and timberlands, net		(5,000)	(25,000)	(9,000)
Operating income	14,699,000	14,065,000	42,284,000	40,974,000
Other non-operating income (expense)
Interest expense	(908,000)	(1,729,000)	(2,665,000)	(4,928,000)
Other, net	238,000	653,000	1,099,000	474,000
Total other non-operating income (expense)	(670,000)	(1,076,000)	(1,566,000)	(4,454,000)
Income (loss) before income taxes	14,029,000	12,989,000	40,718,000	36,520,000
Income tax provision (benefit)	3,967,000	3,213,000	11,165,000	6,251,000
Net income (loss)	10,062,000	9,776,000	29,553,000	30,269,000
Other comprehensive income (loss)	5,356,000	(11,057,000)	1,366,000	2,187,000
Comprehensive income	15,418,000	(1,281,000)	30,919,000	32,456,000
Adjustments/ Eliminations [Member]
Condensed Consolidated Statements of Income
Net sales	(13,936,000)	(13,060,000)	(41,318,000)	(37,878,000)
Total revenues	(13,936,000)	(13,060,000)	(41,318,000)	(37,878,000)
Costs of products sold	(13,904,000)	(13,081,000)	(41,260,000)	(38,079,000)
Gross profit	(32,000)	21,000	(58,000)	201,000
Operating income	(32,000)	21,000	(58,000)	201,000
Other non-operating income (expense)
Interest expense				(3,300,000)
Other, net	(12,527,000)	(11,591,000)	(38,263,000)	(34,986,000)
Total other non-operating income (expense)	(12,527,000)	(11,591,000)	(38,263,000)	(38,286,000)
Income (loss) before income taxes	(12,559,000)	(11,570,000)	(38,321,000)	(38,085,000)
Income tax provision (benefit)	(13,000)	7,000	(25,000)	(1,166,000)
Net income (loss)	(12,546,000)	(11,577,000)	(38,296,000)	(36,919,000)
Other comprehensive income (loss)	9,279,000	19,341,000	(3,181,000)	(2,292,000)
Comprehensive income	$ (21,825,000)	$ 7,764,000	$ (41,477,000)	$ (39,211,000)