Quarterly Results for 2011 and 2010 (UNAUDITED) (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2010		Sep. 30, 2010		Jun. 30, 2010		Mar. 31, 2010		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Accrual for Environmental Loss Contingencies, Increase (Decrease) for Revision in Estimates																	$ 6,873,000		$ 3,201,000		$ 2,111,000
Gain (Loss) on Sale of Previously Unissued Stock by Equity Investee																	0		12,367,000		0
Gain (Loss) on Sale of Previously Unissued Stock by Equity Investee, Net of Tax																			11,500,000
Selected Quarterly Financial Information [Abstract]
Revenue, Net	388,423,000		385,091,000		357,397,000		357,731,000		315,308,000		377,515,000		312,210,000		310,200,000		1,488,642,000		1,315,233,000		1,168,567,000
Operating Income (Loss)	81,325,000	[1]	108,310,000		79,073,000		87,578,000		56,665,000		92,082,000		56,344,000		76,860,000	[2]	356,286,000		281,951,000		409,508,000
Net Income (Loss) Attributable to Parent	56,230,000	[1]	104,909,000	[3]	56,454,000		58,412,000		59,171,000	[4]	62,904,000		38,558,000		56,953,000	[2]	276,005,000		217,586,000		312,541,000
Earnings Per Share, Basic	$ 0.46	[5]	$ 0.86	[5]	$ 0.46	[5]	$ 0.48	[5]	$ 0.49	[5]	$ 0.52	[5]	$ 0.32	[5]	$ 0.48	[5]	$ 2.27	[5]	$ 1.81	[5]	$ 2.63
Earnings Per Share, Diluted	$ 0.45	[5]	$ 0.84	[5]	$ 0.45	[5]	$ 0.47	[5]	$ 0.48	[5]	$ 0.51	[5]	$ 0.32	[5]	$ 0.47	[5]	$ 2.20	[5]	$ 1.79	[5]	$ 2.60
Taxability of the alternative fuel mixture credit
Tax Adjustments, Settlements, and Unusual Provisions			16,000,000														16,000,000
Cellulosic Biofuel Producer Credit
Tax Adjustments, Settlements, and Unusual Provisions									24,300,000
Port Angeles Increase in Disposition Reserve [Member]
Accrual for Environmental Loss Contingencies, Increase (Decrease) for Revision in Estimates																	6,500,000
Effect of Increase (Decrease) in Reserve for Revision in Estimates, Net of Tax																	$ 4,100,000

[1] Fourth quarter 2011 included a pre-tax $6.5 million ($4.1 million after tax) increase in a disposition reserve.

[2] First quarter 2010 included a pre-tax $12.4 million ($11.5 million after tax) gain from the sale of a portion of the Company's interest in its New Zealand JV. See Note 5 — Joint Venture Investment for further information.

[3] Third quarter 2011 included a benefit of $16.0 million from the reversal of a reserve related to the taxability of the AFMC.

[4] Fourth quarter 2010 included a tax benefit of $24.3 million related to the CBPC. See Note 8 — Income Taxes.

[5] The impact of the August 2011 three-for-two stock split is reflected for all periods presented. See Note 9 — Earnings per Common Share for further information.