Derivative Financial Instruments and Hedging Activities - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended										3 Months Ended							3 Months Ended		12 Months Ended
	Aug. 31, 2007	Aug. 31, 2014		Aug. 31, 2013		Feb. 28, 2011 Interest rate swap Fair value hedging	Aug. 31, 2007 Interest rate swap Cash Flow Hedging	Aug. 31, 2014 Forward contracts Forward foreign exchange contracts	Aug. 31, 2013 Forward contracts Forward foreign exchange contracts	Aug. 31, 2014 Forward contracts Forward foreign exchange contracts Cash Flow Hedging	Aug. 31, 2013 Forward contracts Forward foreign exchange contracts Cash Flow Hedging	Aug. 31, 2009 7.750% Senior Notes Due 2016	Aug. 31, 2014 7.750% Senior Notes Due 2016		Aug. 31, 2013 7.750% Senior Notes Due 2016		Aug. 31, 2011 7.750% Senior Notes Due 2016	Feb. 28, 2011 7.750% Senior Notes Due 2016	May 31, 2008 8.250% Senior Notes Due 2018	Feb. 29, 2008 8.250% Senior Notes Due 2018	Aug. 31, 2014 8.250% Senior Notes Due 2018		Aug. 31, 2013 8.250% Senior Notes Due 2018		Aug. 31, 2007 8.250% Senior Notes Due 2018
Derivative [Line Items]
Aggregate notional amount outstanding						$ 200,000,000	$ 400,000,000	$ 1,200,000,000	$ 1,200,000,000	$ 626,900,000	$ 565,000,000
Senior unsecured notes, interest rate												7.75%	7.75%	[1]	7.75%	[1]		7.75%	8.25%	8.25%	8.25%	[2]	8.25%	[2]	8.25%
Fair value of interest rate swap including accrued interest on interest rate swap																	12,200,000
Accrued interest on interest rate swaps																	600,000
Amortization of interest rate swaps		2,400,000
Hedge accounting adjustment related to terminated interest rate swaps		4,450,000	[3]	6,823,000	[3]
Payment to settle interest rate swaps	$ 43,100,000
Expiry date												Jul. 15, 2016							Mar. 15, 2018	Mar. 15, 2018	Mar. 15, 2018

[1] During the fourth quarter of fiscal year 2009, the Company issued $312.0 million of seven-year, publicly-registered 7.750% notes (the "7.750% Senior Notes") at 96.1% of par, resulting in net proceeds of approximately $300.0 million. The 7.750% Senior Notes mature on July 15, 2016 and pay interest semiannually on January 15 and July 15. Also, the 7.750% Senior Notes are the Company's senior unsecured obligations and rank equally with all other existing and future senior unsecured debt obligations.

[2] During the second and third quarters of fiscal year 2008, the Company issued $250.0 million and $150.0 million, respectively, of ten-year, unregistered 8.250% notes at 99.965% of par and 97.5% of par, respectively, resulting in net proceeds of approximately $245.7 million and $148.5 million, respectively. On July 18, 2008, the Company completed an exchange whereby all of the outstanding unregistered 8.250% notes were exchanged for registered 8.250% notes (collectively the "8.250% Senior Notes") that are substantially identical to the unregistered notes except that the 8.250% Senior Notes are registered under the Securities Act and do not have any transfer restrictions, registration rights or rights to additional special interest. The 8.250% Senior Notes mature on March 15, 2018 and pay interest semiannually on March 15 and September 15. The interest rate payable on the 8.250% Senior Notes is subject to adjustment from time to time if the credit ratings assigned to the 8.250% Senior Notes increase or decrease, as provided in the 8.250% Senior Notes. The 8.250% Senior Notes are the Company's senior unsecured obligations and rank equally with all other existing and future senior unsecured debt obligations.

[3] This amount represents the fair value hedge accounting adjustment related to the 7.750% Senior Notes. For further discussion of the Company's fair value hedges, see Note 13 - "Derivative Financial Instruments and Hedging Activities" to the Consolidated Financial Statements