INCOME TAXES AFMC for CBPC exchange Narrative (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended		3 Months Ended
	Dec. 31, 2009 tax_credit	Dec. 31, 2009 Alternative Fuel Mixture Credit [Member]	Dec. 31, 2009 Cellulosic Biofuel Producer Credit [Member]	Mar. 31, 2013 Exchange of Alternative Fuel Tax Benefit [Member] gal
AFMC for CBPC Exchange [Line Items]
Number of tax credits	2
Tax Credit Amount per Gallon		0.50	1.01
Tax payment				$ 70
Gallons Exchanged				120,000,000
Income Tax Benefit				$ 19