Revenues - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2019	Nov. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 7,621,485	$ 8,484,289
Energy
Disaggregation of Revenue [Line Items]
Revenues	1,895,423	2,161,288
Ag
Disaggregation of Revenue [Line Items]
Revenues	5,711,855	6,305,397
Corporate and Other
Disaggregation of Revenue [Line Items]
Revenues	14,207	17,604
ASC 606
Disaggregation of Revenue [Line Items]
Revenues	3,058,015	3,301,250
ASC 606 | Energy
Disaggregation of Revenue [Line Items]
Revenues	1,693,848	1,940,190
ASC 606 | Ag
Disaggregation of Revenue [Line Items]
Revenues	1,358,626	1,355,826
ASC 606 | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenues	5,541	5,234
ASC 815
Disaggregation of Revenue [Line Items]
Revenues	4,517,662	5,134,526
ASC 815 | Energy
Disaggregation of Revenue [Line Items]
Revenues	201,575	221,098
ASC 815 | Ag
Disaggregation of Revenue [Line Items]
Revenues	4,316,087	4,913,428
ASC 815 | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenues	0	0
Other Guidance
Disaggregation of Revenue [Line Items]
Revenues	45,808	48,513
Other Guidance | Energy
Disaggregation of Revenue [Line Items]
Revenues	0	0
Other Guidance | Ag
Disaggregation of Revenue [Line Items]
Revenues	37,142	36,143
Other Guidance | Corporate and Other
Disaggregation of Revenue [Line Items]
Revenues	$ 8,666	$ 12,370