Derivative Financial Instruments and Hedging Activities Derivatives (Details) - USD ($)	3 Months Ended	9 Months Ended
	May. 31, 2015	May. 31, 2014	Aug. 31, 2014
Purchase and Sales Contracts [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	$ 517,899,000		$ 560,530,000
Derivative Asset, Fair Value, Gross Asset	605,024,000		603,933,000
Derivative Asset, Fair Value, Gross Amount Not Offset on Balance Sheet	87,125,000		43,403,000
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	425,218,000		554,083,000
Derivative Liability, Fair Value, Gross Liability	529,172,000		599,990,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	16,829,000		2,504,000
Derivative Liability, Fair Value, Gross Amount Not Offset on Balance Sheet	87,125,000		43,403,000
Commodity and Freight Derivatives [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	493,623,000		554,981,000
Derivative Asset, Fair Value, Gross Asset	573,592,000		597,210,000
Derivative Asset, Fair Value, Gross Amount Not Offset on Balance Sheet	79,969,000		42,229,000
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	403,339,000		552,879,000
Derivative Liability, Fair Value, Gross Liability	500,137,000		597,612,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	16,829,000		2,504,000
Derivative Liability, Fair Value, Gross Amount Not Offset on Balance Sheet	79,969,000		42,229,000
Foreign Exchange Contract [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	9,627,000		1,349,000
Derivative Asset, Fair Value, Gross Asset	16,783,000		2,523,000
Derivative Asset, Fair Value, Gross Amount Not Offset on Balance Sheet	7,156,000		1,174,000
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	15,731,000		1,074,000
Derivative Liability, Fair Value, Gross Liability	22,887,000		2,248,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0		0
Derivative Liability, Fair Value, Gross Amount Not Offset on Balance Sheet	7,156,000		1,174,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	14,649,000		4,200,000
Derivative Asset, Fair Value, Gross Asset	14,649,000		4,200,000
Derivative Asset, Fair Value, Gross Amount Not Offset on Balance Sheet	0		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	6,064,000
Derivative Liability, Fair Value, Gross Liability	6,064,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0
Derivative Liability, Fair Value, Gross Amount Not Offset on Balance Sheet	0
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Purchase and Sales Contracts [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	84,000		130,000
Derivative Liability, Fair Value, Gross Liability	84,000		130,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0		0
Derivative Liability, Fair Value, Gross Amount Not Offset on Balance Sheet	0		0
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Purchase and Sales Contracts [Line Items]
Gain on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring		$ 13,500,000
Foreign Exchange Contract [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Notional Amount	912,400,000		$ 784,400,000
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Purchase and Sales Contracts [Line Items]
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge	8,300,000
Fair Value Hedging [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Notional Amount	420,000,000
Cash Flow Hedging [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Notional Amount	300,000,000
Interest Rate Contracts, Expiring At Various Times Through Fiscal 2018 [Member] | Not Designated as Hedging Instrument [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Notional Amount	3,400,000
Interest Rate Contracts, Expiring During Fiscal 2015 [Member] | Not Designated as Hedging Instrument [Member]
Purchase and Sales Contracts [Line Items]
Derivative Asset, Notional Amount	100,000
Interest Rate Contracts, Expiring during Fiscal 2016 [Member] | Designated as Hedging Instrument [Member]
Purchase and Sales Contracts [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 0