Share-based Compensation Restricted Stock Units (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Aug. 31, 2014		Aug. 31, 2013		Aug. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock or Unit Expense	$ 6		$ 6		$ 7
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	219,504		217,001		146,481
Award Vesting Period	5 years
Award Vesting Rights, Percentage	20.00%
Grants In Period Total Fair Value	7		7		6
Compensation Cost Not yet Recognized	$ 7
Compensation Cost Not yet Recognized, Period for Recognition	2 years 3 months 15 days
Number of Shares:
Outstanding, Beginning Balance	311,000		303,000		348,000
Granted	219,504		217,001		146,481
Vested	(93,000)		(174,000)		(148,000)
Forfeited	(49,000)		(35,000)		(43,000)
Outstanding, Ending Balance	389,000		311,000		303,000
Weighted Average Grant Date Fair Value:
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance	$ 39.11		$ 49.46		$ 54.06
Granted, Weighted Average Grant Date Fair Value	$ 30.55		$ 30.36		$ 42.63
Vested, Weighted Average Grant Date Fair Value	$ 42.13		$ 46.04		$ 52.93
Forfeited, Weighted Average Grant Date Fair Value	$ 35.73		$ 40.02		$ 51.47
Nonvested, Weighted Average Grant Date Fair Value, Ending Balance	$ 33.97		$ 39.11		$ 49.46
Restricted Stock Units (RSUs) | Class A Common Stock
Common Stock Fair Value:
Common Stock Fair Value	$ 25.01	[1]	$ 24.69	[1]	$ 28.43	[1]

[1] Amounts represent the value of the Company’s Class A common stock on the date that the restricted stock units vested.