Supplemental Cash Flow and Other Information (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Jul. 31, 2017	Jun. 30, 2018	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	May 31, 2017	Feb. 28, 2017	Nov. 30, 2016
Net cash paid during the period for:
Interest			$ 148,874	$ 160,040	$ 147,089
Income taxes			13,410	14,571	5,184
Other significant noncash investing and financing transactions:
Notes receivable reacquired under Securitization Facility			615,089	0	0
Trade receivables reacquired under Securitization Facility			402,421	0	0
Securitized debt reacquired under Securitization Facility			634,000	0	0
Deferred purchase price receivable extinguished under Securitization Facility			386,900	0	0
Notes receivable sold under Securitization Facility			0	747,345	0
Securitized debt extinguished under Securitization Facility	$ 554,000	$ 634,000	0	554,000	0
Deferred purchase price receivable recognized under Securitization Facility			0	547,553	0
Land and improvements received for notes receivable			0	138,699	0
Capital expenditures and major repairs incurred but not yet paid			53,453	22,490	44,307
Capital lease obligations incurred			396	6,832	23,921
Capital equity certificates redeemed with preferred stock			0	19,985	76,756
Capital equity certificates issued in exchange for Ag acquisitions			0	2,928	19,089
Accrual of dividends and equities payable			$ 153,941	$ 12,121	$ 162,439	$ 209,718	$ 128,700	$ 121,209	$ 134,718	$ 131,380	$ 239,857