Restricted Stock Activity (Detail) (USD $)	12 Months Ended
	Aug. 31, 2012
Number of non-vested shares
Shares, non-vested beginning balance	14,097,278
Changes during the period
Shares granted	5,233,078	[1]
Shares vested	(5,920,301)
Shares forfeited	(464,191)
Shares, non-vested ending balance	12,945,864
Weighted-Average Grant-Date Fair Value
Weighted-Average Grant-Date Fair Value, beginning balance	$ 12.91
Changes during the period
Weighted-Average Grant-Date Fair Value, Shares granted	$ 19.43	[1]
Weighted-Average Grant-Date Fair Value, Shares vested	$ 10.39
Weighted-Average Grant-Date Fair Value, Shares forfeited	$ 15.77
Weighted-Average Grant-Date Fair Value, ending balance	$ 16.33

[1] For those shares granted that are based on the achievement of certain performance criteria, represents the maximum number of shares that can vest.