Long-Term Indebtedness (Details) - USD ($) $ in Thousands	Feb. 29, 2016	Aug. 31, 2015
Debt Instrument [Line Items]
Total Senior Indebtedness	$ 588,059	$ 588,059
Less: current maturities of long-term debt	11,250	3,750
Total long-term debt, less current maturities	576,809	584,309
Line of Credit
Debt Instrument [Line Items]
Total Senior Indebtedness	300,000	300,000
Line of Credit | Senior Credit Facility - Revolver
Debt Instrument [Line Items]
Total Senior Indebtedness	0	0
Line of Credit | Senior Credit Facility - Term Loan
Debt Instrument [Line Items]
Total Senior Indebtedness	300,000	300,000
Senior Notes | 5.625% Senior Notes
Debt Instrument [Line Items]
Senior Notes, Noncurrent	$ 288,059	$ 288,059