Note 12. Stockholders' Equity (Detail) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2011	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010	May 08, 2012
Preferred Stock, Shares Authorized		10,000,000	10,000,000
Preferred Stock, Par or Stated Value Per Share (in Dollars per share)		$ 0.01	$ 0.01
Common Stock, Par or Stated Value Per Share (in Dollars per share)		$ 0.01	$ 0.01
Common Stock, Shares Authorized	100,000,000	150,000,000	100,000,000
Treasury Stock, Shares, Retired	16,658,741
Treasury Stock, Value (in Dollars)	$ 850,900,000	$ 122,749,000	$ 824,382,000
StockRepurchaseProgramIncreaseInAuthorizedAmount (in Dollars)					200,000,000
Stock Repurchased During Period, Shares		1,644,000	2,252,000	2,784,000
Stock Repurchased During Period, Value (in Dollars)		153,000,000	217,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount (in Dollars)		190,000,000	142,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures			154,281
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		14,258
Common Stock [Member]
Treasury Stock, Retired, Cost Method, Amount (in Dollars)	200,000	167,000
Additional Paid-in Capital [Member]
Treasury Stock, Retired, Cost Method, Amount (in Dollars)	361,400,000	361,482,000
Retained Earnings [Member]
Treasury Stock, Retired, Cost Method, Amount (in Dollars)	$ 489,300,000	$ 489,286,000