Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended					12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2014 Estimate of Fair Value Measurement [Member]	Apr. 01, 2014 Estimate of Fair Value Measurement [Member]	Aug. 31, 2014 Restricted Stock	Aug. 31, 2013 Restricted Stock	Aug. 31, 2012 Restricted Stock	Aug. 31, 2014 Maximum	Aug. 31, 2014 Stock Option	Aug. 31, 2013 Stock Option	Aug. 31, 2012 Stock Option	Aug. 31, 2014 Stock Appreciation Rights (SARs)	Aug. 31, 2013 Stock Appreciation Rights (SARs)	Aug. 31, 2012 Stock Appreciation Rights (SARs)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Maturity period of highly liquid instruments									90 days
Cash equivalents outstanding	$ 9,600,000	$ 6,500,000
Allowance for doubtful accounts	2,000,000	2,600,000
Common shares excluded from computation of diluted earnings per share						3,373,275				1,870,150	3,664,364	3,748,037	3,864,131	4,485,266	4,930,935
Senior Non-Convertible Cumulative Preferred Stock				33,500,000	33,200,000
Recognition of stock based compensation expense related to the Company's employee stock purchase plan	8,994,000	62,574,000	74,944,000
Reversal to stock-based compensation expense	45,800,000					45,800,000
Stock based compensation expense, tax effect	1,100,000	(200,000)	1,300,000
Recognition of stock based compensation expense	4,700,000	4,000,000	4,000,000
Stock-based compensation expense classified as inventories	300,000	300,000
Cash received from exercise of share-based payment arrangements	15,771,000	18,285,000	26,003,000
Treasury stock minimum tax withholding related to vesting of restricted stock	34,312,000	20,290,000	31,205,000
Restricted shares vested and resulted in withholding						1,569,059	1,184,162	1,590,721
Net tax benefit (expense) of actuarial loss included in accumulated other comprehensive income	8,100,000	6,900,000
Net tax benefit (expense) of prior service cost included in accumulated other comprehensive income	(400,000)	(300,000)
Unrealized gains (losses) on derivative instruments net of tax benefits	$ 13,600,000	$ 14,100,000