Derivatives (Details 2)	3 Months Ended
	Mar. 31, 2012 T lb gal
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	493,807,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	177,668,000
Amount of quantities of price risk derivative instruments not designated as hedging instrument	84,684,000
Amounts of quantities of price risk derivative instruments not designated as hedging instruments	62,000
Non-exchange Traded [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	300,257,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	176,818,000
Amount of quantities of price risk derivative instruments not designated as hedging instrument	66,684,000
Amounts of quantities of price risk derivative instruments not designated as hedging instruments	62,000
Non-exchange Traded [Member] | Corn [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	249,893,000
Non-exchange Traded [Member] | Soybeans [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	23,214,000
Non-exchange Traded [Member] | Wheat [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	16,179,000
Non-exchange Traded [Member] | Oats [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	10,971,000
Non-exchange Traded [Member] | Ethanol [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	176,818,000
Non-exchange Traded [Member] | Corn Oil [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instrument	66,684,000
Non-exchange Traded [Member] | Other [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amounts of quantities of price risk derivative instruments not designated as hedging instruments	62,000
Exchange Traded [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	193,550,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	850,000
Amount of quantities of price risk derivative instruments not designated as hedging instrument	18,000,000
Exchange Traded [Member] | Corn [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	110,250,000
Exchange Traded [Member] | Soybeans [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	33,410,000
Exchange Traded [Member] | Wheat [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	46,855,000
Exchange Traded [Member] | Oats [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	3,035,000
Exchange Traded [Member] | Ethanol [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	840,000
Exchange Traded [Member] | Bean Oil [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instrument	18,000,000
Exchange Traded [Member] | Other [Member]
Amounts of quantities outstanding included in commodity derivative contracts
Amount of quantities of price risk derivative instruments not designated as hedging instruments	10,000