Fair Value (Financial Assets And Financial Liabilities Measured At Fair Value On Recurring Basis) (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Feb. 29, 2012		Aug. 31, 2011
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market investments	$ 138,041		$ 153,839
Derivative assets	62,697		52,858
Nonqualified benefit plan assets	52,815	[1]	49,357	[1]
Derivative liabilities	7,939		5,688
Nonqualified benefit plan liabilities	82,887	[1]	81,167	[1]
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market investments	138,041		153,839
Derivative assets	2,285		2,329
Nonqualified benefit plan assets	52,815	[1]	49,357	[1]
Derivative liabilities	3,679		2,625
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	60,412		50,529
Derivative liabilities	4,260		3,063
Nonqualified benefit plan liabilities	$ 82,887	[1]	$ 81,167	[1]

[1] The Company provides a nonqualified benefit restoration plan to certain eligible executives equal to amounts that would have been available under tax qualified ERISA plans but for limitations of ERISA, tax laws and regulations. Though under no obligation to fund this plan, the Company has segregated assets in a trust. The plan assets and liabilities consist of securities included in various mutual funds.