Derivatives Gains (Losses) included in Other Comprehensive Income in Derivatives Accounted for as Hedging Instruments, Net of Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	$ (10,070)	$ (4,078)	$ (10,580)
Interest Expense, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	$ (5,071)	$ (792)	$ 12,727