Derivatives (Details 3)	Dec. 31, 2011 T bushels gal
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	228,814,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	98,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	239,240,000
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	200,072,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	10,568,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	6,593,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	11,581,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	239,240,000
Non-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	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	98,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	161,720,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	29,473,000
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	96,500,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	16,570,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	46,935,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	1,715,000
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
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	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	29,463,000
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	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	0
Amount of quantities of price risk derivative instruments not designated as hedging instruments	10,000