Earnings Per Share and Dividends - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares relating to outstanding stock awards	0	53,000	120,000	77,000
Dilutive unvested restricted stock awards	0	4,293,000	1,767,000	4,004,000
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares excluded from computation of diluted earnings per share	1,721,068	3,695,450	2,159,270	3,718,067
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares excluded from computation of diluted earnings per share	3,737,859
Stock Appreciation Rights (SARs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares excluded from computation of diluted earnings per share	4,172,787	4,551,902	4,200,998	4,578,718