Income Taxes - Rollforward of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balances	$ 72,181	$ 72,181	$ 67,271
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	1,387	0	0
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	0	0	35,718
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(36,463)	0	(9,867)
Reductions attributable to statute expiration	0	0	(20,941)
Balances at August 31	$ 37,105	$ 72,181	$ 72,181