Share-Based Compensation (Details) (USD $)	3 Months Ended
	Nov. 30, 2011 Year
Schedule of shares subject to options and SARs
Options and SARs, Outstanding, Number Outstanding, Beginning Balance	2,807,498
Options and SARs, Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 27.45
Options and SARs, Granted, Number	825,655
Options and SARs, Granted, Weighted Average Exercise Price	$ 11.60
Options and SARs, Forfeited / Expired, Number	(17,730)
Options and SARs, Forfeited, / Expired Weighted Average Exercise Price	$ 28.28
Options and SARs, Outstanding, Number Outstanding, Ending Balance	3,615,423
Options and SARs, Outstanding, Weighted Average Exercise Price, Ending Balance	$ 23.83
Options and SARs, Outstanding, Weighted Average Remaining Contractual Life (Years)	3.5
Options and SARs, Exercisable, Number Outstanding	2,621,768
Options and SARs, Exercisable, Weighted Average Exercise Price	$ 28.19
Options and SARs, Exercisable, Weighted Average Remaining Contractual Life (Years)	2.3