Income Taxes AFMC and CBPC (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Credits and Adjustments			$ 205,229,000
Alternative Fuel Mixture Credit [Member]
Tax Credit Amount per Gallon			0.50
Income Tax Credits and Adjustments	0	0	205,229,000
Cellulosic Biofuel Producer Credit
Tax Credit Amount per Gallon			1.01
Income Tax Credits and Adjustments		24,300,000
Exchange of Alternative Fuel Tax Benefit [Member]
Income Tax Credits and Adjustments	$ 5,800,000