Pending GrainCorp Acquisition (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	May 01, 2013 AUD
Pending GrainCorp Acquisition [Abstract]
Equity interest as a percent	19.80%		19.80%
Potential cash offer to acquire an entity per share					12.20
Aggregate transaction value related to potential acquisition					3,400,000,000
Dividends to be paid by acquiree as part of acquisition agreement					1.00
Additional equity per acceptance of offer as a percent	8.00%		8.00%
Expected ownership interest as a percent	28.00%		28.00%
(Gain) Loss on Australian foreign exchange hedges	$ (26,000,000)	$ 0	$ 25,000,000	$ 0