Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017
Property, Plant and Equipment [Line Items]
Assets under capital leases	$ 62,700	$ 50,000
Accumulated amortization on assets under capital leases	20,600	18,900
Impairment charge	40,340	(10,352)	$ 145,042
Depreciation expense	495,300	475,800	$ 475,900
Ag
Property, Plant and Equipment [Line Items]
Impairment charge	$ 12,200
Reserve and impairment charges [Member] | Ag
Property, Plant and Equipment [Line Items]
Impairment charge		30,400
Reserve and impairment charges [Member] | Energy
Property, Plant and Equipment [Line Items]
Impairment charge		$ 32,700