Segment Reporting - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Aug. 31, 2019	Mar. 01, 2019
Segment Reporting Information [Line Items]
Remainingownershipacquired				75.00%
Revenues	$ 7,621,485	$ 8,484,289
Operating earnings (loss)	157,212	314,498
Interest Expense	34,971	38,908
Other (income) loss	(13,498)	(25,134)
Equity (income) loss from investments	(49,662)	(66,508)
Income (loss) before income taxes	185,401	367,232
Total assets	17,214,291		$ 16,447,494
Energy
Segment Reporting Information [Line Items]
Revenues, including intersegment revenues	2,027,895	2,310,080
Revenues	1,895,423	2,161,288
Operating earnings (loss)	161,199	235,639
Interest Expense	374	4,237
Other (income) loss	(964)	(986)
Equity (income) loss from investments	(364)	(73)
Income (loss) before income taxes	162,153	232,461
Total assets	4,449,652
Ag
Segment Reporting Information [Line Items]
Revenues, including intersegment revenues	5,715,994	6,308,714
Revenues	5,711,855	6,305,397
Operating earnings (loss)	(417)	80,127
Interest Expense	20,741	21,000
Other (income) loss	(11,453)	(22,400)
Equity (income) loss from investments	4,157	1,209
Income (loss) before income taxes	(13,862)	80,318
Total assets	7,108,507
Nitrogen Production [Member]
Segment Reporting Information [Line Items]
Revenues, including intersegment revenues	0	0
Operating earnings (loss)	(7,823)	(5,128)
Interest Expense	12,130	13,679
Other (income) loss	(1,569)	(1,571)
Equity (income) loss from investments	(34,834)	(40,915)
Income (loss) before income taxes	16,450	23,679
Total assets	2,761,709
Corporate and Other
Segment Reporting Information [Line Items]
Revenues, including intersegment revenues	15,950	19,067
Revenues	14,207	17,604
Operating earnings (loss)	4,253	3,860
Interest Expense	3,838	763
Other (income) loss	(1,624)	(948)
Equity (income) loss from investments	(18,621)	(26,729)
Income (loss) before income taxes	20,660	30,774
Total assets	2,894,423
Reconciling Amounts
Segment Reporting Information [Line Items]
Revenues	(138,354)	(153,572)
Operating earnings (loss)	0	0
Interest Expense	(2,112)	(771)
Other (income) loss	2,112	771
Equity (income) loss from investments	0	0
Income (loss) before income taxes	0	0
Total assets	0
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Intersegment Eliminations [Member] | Energy
Segment Reporting Information [Line Items]
Revenues	(132,472)	(148,792)
Intersegment Eliminations [Member] | Ag
Segment Reporting Information [Line Items]
Revenues	(4,139)	(3,317)
Intersegment Eliminations [Member] | Nitrogen Production [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Intersegment Eliminations [Member] | Corporate and Other
Segment Reporting Information [Line Items]
Revenues	(1,743)	(1,463)
Intersegment Eliminations [Member] | Reconciling Amounts
Segment Reporting Information [Line Items]
Revenues	$ 138,354	$ 153,572