Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Income [Abstract]
Net sales	$ 397,985	$ 362,781	$ 794,756	$ 700,056
Energy and related sales - net	2,060	1,915	5,047	5,522
Total revenues	400,045	364,696	799,803	705,578
Costs of products sold	362,545	329,236	702,136	625,902
Gross profit	37,500	35,460	97,667	79,676
Selling, general and administrative expenses	31,320	28,847	63,090	63,517
Gains on dispositions of plant, equipment and timberlands, net	(29)	(168)	(3,204)	(168)
Operating income	6,209	6,781	37,781	16,327
Other non-operating income (expense)
Interest expense	(6,461)	(6,817)	(12,921)	(12,480)
Interest income	150	168	357	338
Other - net	(275)	366	(268)	(3,617)
Total other non-operating expense	(6,586)	(6,283)	(12,832)	(15,759)
Income (loss) before income taxes	(377)	498	24,949	568
Income tax provision (benefit)	(2,878)	395	5,022	839
Net income (loss)	$ 2,501	$ 103	$ 19,927	$ (271)
Earnings (loss) per share
Basic	$ 0.05	$ 0	$ 0.43	$ (0.01)
Diluted	$ 0.05	$ 0	$ 0.43	$ (0.01)
Cash dividends declared per common share	$ 0.09	$ 0.09	$ 0.18	$ 0.18
Weighted average shares outstanding
Basic	46,080	45,908	46,075	45,872
Diluted	46,633	46,313	46,502	45,872