Note 11. Stockholders' Equity (Detail) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended	6 Months Ended
	Jun. 13, 2011	Feb. 29, 2012	Feb. 29, 2012	Feb. 28, 2011	Aug. 31, 2011	Aug. 31, 2010
Preferred Stock, Shares Authorized (in Shares)		10,000,000	10,000,000		10,000,000
Preferred Stock, Par or Stated Value Per Share (in Dollars per share)		$ 0.01	$ 0.01		$ 0.01
Common Stock, Par or Stated Value Per Share (in Dollars per share)		$ 0.01	$ 0.01		$ 0.01
Common Stock, Shares Authorized (in Shares)		150,000,000	150,000,000		150,000,000	100,000,000
Treasury Stock, Shares, Retired (in Shares)		16,658,741
Treasury Stock, Retired, Par Value Method, Amount		$ 850.9
StockRepurchaseProgramIncreaseInAuthorizedAmount	200
Stock Repurchased During Period, Shares (in Shares)			657,800	809,000
Stock Repurchased During Period, Value			59.6
Stock Repurchase Program, Remaining Authorized Repurchase Amount			83
Par Value [Member]
Treasury Stock, Retired, Par Value Method, Amount		0.2
APIC [Member]
Treasury Stock, Retired, Par Value Method, Amount		361.4
Retained Earning [Member]
Treasury Stock, Retired, Par Value Method, Amount		$ 489.3