Derivatives Reconcilation of Gross and Net (Details) - USD ($) $ in Thousands	Aug. 31, 2016	Aug. 31, 2015
Reconciliation of gross and net fair value of assets and liabilities subject to offsetting arrangements [Line Items]
Derivative Assets	$ 543,821	$ 513,441
Derivative asset, fair value, gross amount not offset on Balance sheet	32,876	70,083
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	510,945	443,358
Derivative Liability, Fair Value, Gross Liability	513,599	470,769
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	811	11,482
Derivative liability, fair value, gross amount not offset on balance sheet	32,876	70,083
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	479,912	389,204
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Reconciliation of gross and net fair value of assets and liabilities subject to offsetting arrangements [Line Items]
Derivative Assets	22,078	14,216
Derivative asset, fair value, gross amount not offset on Balance sheet	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	22,078	14,216
Derivative Liability, Fair Value, Gross Liability		6,058
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		0
Derivative liability, fair value, gross amount not offset on balance sheet		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		6,058
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Reconciliation of gross and net fair value of assets and liabilities subject to offsetting arrangements [Line Items]
Derivative Assets	21,551	23,154
Derivative asset, fair value, gross amount not offset on Balance sheet	9,187	11,682
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	12,364	11,472
Derivative Liability, Fair Value, Gross Liability	22,289	37,598
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative liability, fair value, gross amount not offset on balance sheet	9,187	11,682
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	13,102	25,916
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Reconciliation of gross and net fair value of assets and liabilities subject to offsetting arrangements [Line Items]
Derivative Liability, Fair Value, Gross Liability	8	61
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative liability, fair value, gross amount not offset on balance sheet	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	8	61
Not Designated as Hedging Instrument [Member] | Commodity and Freight Derivatives [Member]
Reconciliation of gross and net fair value of assets and liabilities subject to offsetting arrangements [Line Items]
Derivative Assets	500,192	476,071
Derivative asset, fair value, gross amount not offset on Balance sheet	23,689	58,401
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	476,503	417,670
Derivative Liability, Fair Value, Gross Liability	491,302	427,052
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	811	11,482
Derivative liability, fair value, gross amount not offset on balance sheet	23,689	58,401
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ 466,802	$ 357,169