Long-Term Indebtedness (Detail) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2014	Aug. 31, 2013
Debt Instrument [Line Items]
Total Senior Indebtedness	$ 390,000	$ 515,000
Less: current maturities of long-term debt	(4,500)	0
Total long-term debt, less current maturities	385,500	515,000
Senior Credit Facility
Debt Instrument [Line Items]
Total Senior Indebtedness	90,000	215,000
Senior Credit Facility | Senior Credit Facility - Revolver
Debt Instrument [Line Items]
Total Senior Indebtedness	0	125,000
Senior Credit Facility | Senior Credit Facility - Term Loan
Debt Instrument [Line Items]
Total Senior Indebtedness	90,000	90,000
Senior Notes | 5.625% Senior Notes
Debt Instrument [Line Items]
Total Senior Indebtedness	$ 300,000	$ 300,000