Notes Payable and Long-Term Debt Outstanding (Parenthetical) (Detail) (USD $)							1 Months Ended					1 Months Ended						3 Months Ended
	May 31, 2012		May 02, 2012	Aug. 31, 2011		May 31, 2012 Variable Interest Entity	Mar. 19, 2012 Amended And Restated Credit Facility	Mar. 19, 2012 Amended And Restated Credit Facility Federal Funds Rate	Mar. 19, 2012 Amended And Restated Credit Facility Libor Rate	Mar. 19, 2012 Minimum Amended And Restated Credit Facility Prime Rate	Mar. 19, 2012 Minimum Amended And Restated Credit Facility Eurocurrency Rate	May 31, 2012 Maximum Year	Mar. 19, 2012 Maximum Amended And Restated Credit Facility Prime Rate	Mar. 19, 2012 Maximum Amended And Restated Credit Facility Eurocurrency Rate	May 31, 2012 7.750% Senior Notes Due 2016	Aug. 31, 2011 7.750% Senior Notes Due 2016	Feb. 28, 2011 7.750% Senior Notes Due 2016	Aug. 31, 2007 8.250% Senior Notes Due 2018	May 31, 2012 8.250% Senior Notes Due 2018	Aug. 31, 2011 8.250% Senior Notes Due 2018	May 31, 2012 5.625% Senior Notes Due 2020	Aug. 31, 2011 5.625% Senior Notes Due 2020
Debt Instrument [Line Items]
Senior Notes, terminated interest rate															7.75%	7.75%	7.75%	8.25%	8.25%	8.25%	5.625%	5.625%
Senior Notes, maturity date															2016	2016			2018	2018	2020	2020
Line of credit revolving facility initial amount							$ 1,300,000,000
Line of credit facility maturity term							5 years
Revolving credit facility potential increase							1,600,000,000
Expiration date							Mar. 19, 2017											Mar. 15, 2018
Percentage added to base rate								0.50%	1.00%	0.175%	1.175%		0.85%	1.85%
VIE credit capacity			60,000,000
Lease agreement period												5
Total assets	7,372,838,000			7,057,940,000		32,200,000
Notes receivable						31,600,000
Total liabilities	5,356,961,000			5,174,117,000		32,300,000
Debt obligation utilized	$ 33,684,000	[1]		$ 2,062,000	[1]	$ 32,200,000

[1] Borrowings under loans On May 2, 2012, the Company entered into a master lease agreement with a variable interest entity (the "VIE") whereby it sells to and subsequently leases back from the VIE up to $60.0 million in certain machinery and equipment for a period of up to five years. In connection with this transaction, the Company holds a variable interest in the VIE, which was designed to hold debt obligations payable to third-party creditors as proceeds from such debt obligations are utilized to finance the purchase of the machinery and equipment that is then leased by the Company. The Company is the primary beneficiary of the VIE as it has both the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. At May 31, 2012, the VIE had approximately $32.2 million of total assets, of which approximately $31.6 million was comprised of a note receivable due from the Company, and approximately $32.3 million of total liabilities, of which approximately $32.2 million were debt obligations to the third-party creditors (as the VIE has utilized approximately $32.2 million of the $60.0 million debt obligation capacity). The third-party creditors have recourse to the Company's general credit only in the event that the Company defaults on its obligations under the terms of the master lease agreement. In addition, the assets held by the VIE can be used only to settle the obligations of the VIE. The Company consolidates the financial statements of the VIE and eliminates all intercompany transactions.