Commitments and Contingencies Schedule of Environmental Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	May 31, 2018	Aug. 31, 2017
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning Balance	$ 48,398
Liabilities Established (Released), Net	7,766
Payments and Other	(2,731)
Ending Balance	53,433
Short-Term	6,684	$ 2,007
Long-Term	$ 46,749	$ 46,391