Fair Value Measurements - Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Nov. 30, 2015	Aug. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Assets, Fair Value Disclosure	$ 73,629	$ 72,571
Other Assets, Fair Value Disclosure	11,745	10,905
Total assets	529,231	596,917
Foreign Currency Contracts, Liability, Fair Value Disclosure	22,551	37,598
Total liabilities	413,908	546,751
Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	24,364	23,155
Commodity and Freight Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	404,915	476,070
Derivative Liability	342,378	427,052
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	14,578	14,216
Derivative Liability	5,286	6,119
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Assets, Fair Value Disclosure	73,629	72,571
Other Assets, Fair Value Disclosure	11,745	10,905
Total assets	110,763	130,452
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Total liabilities	45,118	58,873
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodity and Freight Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	25,389	46,976
Derivative Liability	45,118	58,873
Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Derivative Liability	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Assets, Fair Value Disclosure	0	0
Other Assets, Fair Value Disclosure	0	0
Total assets	418,468	466,465
Foreign Currency Contracts, Liability, Fair Value Disclosure	22,551	37,598
Total liabilities	325,097	411,896
Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	24,364	23,155
Significant Other Observable Inputs (Level 2) | Commodity and Freight Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	379,526	429,094
Derivative Liability	297,260	368,179
Significant Other Observable Inputs (Level 2) | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	14,578	14,216
Derivative Liability	5,286	6,119
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Assets, Fair Value Disclosure	0	0
Other Assets, Fair Value Disclosure	0	0
Total assets	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Total liabilities	43,693	75,982
Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Commodity and Freight Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Derivative Liability	0	0
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Derivative Liability	0	0
NCRA [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued liability for contingent crack spread payments related to purchase of noncontrolling interest		75,982
NCRA [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued liability for contingent crack spread payments related to purchase of noncontrolling interest	0	0
NCRA [Member] | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued liability for contingent crack spread payments related to purchase of noncontrolling interest	0	0
NCRA [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued liability for contingent crack spread payments related to purchase of noncontrolling interest	$ 43,693	$ 75,982