Commitments and Contingencies Schedule of Environmental Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	May 31, 2017	Aug. 31, 2016
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$ 46,350
Liabilities Established (Released), Net	2,407
Payments and Other	(570)
Ending balance	48,187
Short-Term	1,903	$ 1,967
Long-Term	46,284	$ 44,383
Auto and Metals Recycling
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	46,122
Liabilities Established (Released), Net	2,349
Payments and Other	(404)
Ending balance	48,067
Short-Term	1,903
Long-Term	46,164
Corporate
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	228
Liabilities Established (Released), Net	58
Payments and Other	(166)
Ending balance	120
Short-Term	0
Long-Term	$ 120