Derivative Instruments and Hedging Activities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 bu	Dec. 31, 2014
Derivative [Line Items]
Interest Rate Derivative Assets, at Fair Value	$ 33
Interest Rate Derivative Liabilities, at Fair Value	0
Number of months price risk cash flow hedges gain loss will be recognized in earnings	12 months
Corn processed per month (in bushels)	76,000,000
Designated As Hedging Instrument [Member]
Derivative [Line Items]
Interest Rate Derivative Assets, at Fair Value	33	21
Interest Rate Derivative Liabilities, at Fair Value		0
After-tax losses in AOCI from commodity cash flow hedge transactions	$ (6)
Corn [Member] | Designated As Hedging Instrument [Member]
Derivative [Line Items]
Historical time period of hedge percentages	12 months
Percentage of anticipated commodity purchases or production hedged during historical hedging period, low end of range (as a percent)	17.00%
Percentage of anticipated commodity purchases or production hedged during historical hedging period, high end of range (as a percent)	71.00%
Percentage of anticipated commodity purchases or production hedged over future hedging period, low end of range (as a percent)	1.00%
Percentage of anticipated commodity purchases or production hedged over future hedging period, high end of range (as a percent)	38.00%
Derivative Hedged Item Time Period	12 months
Ethanol [Member] | Designated As Hedging Instrument [Member]
Derivative [Line Items]
Derivative Hedged Item Past Period of Time Hedged Volumes	12 months
Commodity sales volume hedged during historical hedging period, low end of range (in gallons)	24,000,000
Commodity sales volume hedged during historical hedging period, high end of range (in gallons)	121,000,000
Derivative Hedged Item Time Period	12 months
Contracted commodity sales volume hedged over future hedging period, low end of range (in gallons)	0
Contracted commodity sales volume hedged over future hedging period, high end of range (in gallons)	31,000,000