Long-Term Indebtedness (Detail) - USD ($) $ in Thousands	Aug. 31, 2015	Aug. 31, 2014
Debt Instrument [Line Items]
Total Senior Indebtedness	$ 588,059	$ 390,000
Less: current maturities of long-term debt	(3,750)	(4,500)
Total long-term debt, less current maturities	584,309	385,500
Senior Credit Facility
Debt Instrument [Line Items]
Total Senior Indebtedness	300,000	90,000
Senior Credit Facility | Senior Credit Facility - Revolver
Debt Instrument [Line Items]
Total Senior Indebtedness	0	0
Senior Credit Facility | Senior Credit Facility - Term Loan
Debt Instrument [Line Items]
Total Senior Indebtedness	300,000	90,000
Senior Notes | 5.625% Senior Notes
Debt Instrument [Line Items]
5.625% Senior Notes Carrying Value	$ 288,059	$ 300,000