Other Assets - Rollforward of Capitalized Maintenance Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012
Capitalized Maintenance Expense [Roll Forward]
Cost Deferred	$ 219,898	$ 3,305	$ 73,701
Amortization	(45,953)	(45,070)	(34,847)
Capitalized major maintenance	$ 241,588	$ 67,643	$ 109,408	$ 70,554
Minimum | Major Maintenance Activities Requiring Shutdown
Finite-Lived Intangible Asset, Useful Life	2 years