Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 140,906	$ 156,313
Accounts receivable, net of allowance for doubtful accounts and customer deductions of $5,494 and $5,034 as of September 30, 2012 and December 31, 2011, respectively	379,675	319,988
Inventories	260,772	254,675
Prepaid expenses and other current assets	27,023	18,298
Federal and state income taxes receivable	82,576
Deferred income taxes	33,881	62,789
Total current assets	924,833	812,063
Property, plant and equipment, net	1,376,457	1,476,654
Goodwill	71,555	58,214
Other intangible assets, net	34,758	25,042
Other long-term assets	47,547	40,526
Total assets	2,455,150	2,412,499
Current liabilities:
Current maturities of long-term debt	15,000	15,000
Capital lease obligations	949	718
Accounts payable	147,308	154,855
Dividends payable	24,578	19,680
Accrued interest	4,672	12,584
Federal and state income taxes payable		10,404
Accrued liabilities	114,750	163,259
Total current liabilities	307,257	376,500
Long-term liabilities:
Long-term debt	782,370	793,448
Capital lease obligations	25,151	21,114
Deferred income taxes	135,361	11,924
Pension and postretirement benefit plans	134,049	148,686
Cellulosic biofuel tax reserve	102,051	102,051
Other long-term liabilities	28,815	29,866
Total long-term liabilities	1,207,797	1,107,089
Stockholders' equity:
Common stock, par value $0.01 per share, 300,000,000 shares authorized, 98,075,652 and 98,324,974 shares issued as of September 30, 2012 and December 31, 2011, respectively	981	983
Additional paid in capital	370,905	351,804
Retained earnings	670,178	673,960
Accumulated other comprehensive loss, net of tax:
Unrealized loss on treasury locks, net	(32,510)	(23,289)
Unrealized loss on foreign currency exchange contracts	(398)	(413)
Unfunded employee benefit obligations	(69,060)	(74,076)
Total accumulated other comprehensive loss	(101,968)	(97,778)
Common stock held in treasury, at cost (2,355 shares as of December 31, 2011)		(59)
Total stockholders' equity	940,096	928,910
Total liabilities and stockholders' equity	$ 2,455,150	$ 2,412,499