Derivative Financial Instruments and Hedging Activities Pretax Gains (Losses) On Derivatives Not Accounted For As Hedging Instruments (Details) (Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Pretax gain (loss) on derivative instruments	$ 151,800	$ (35,991)	$ 211,269	$ (449,937)
Commodity and Freight Derivatives [Member] | Cost of goods sold
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Pretax gain (loss) on derivative instruments	157,461	(22,457)	218,883	(452,747)
Foreign Exchange Contract [Member] | Cost of goods sold
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Pretax gain (loss) on derivative instruments	(5,685)	(13,648)	(7,688)	2,570
Interest rate derivatives | Interest, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Pretax gain (loss) on derivative instruments	$ 24	$ 114	$ 74	$ 240