Investments - Narrative (Details) $ in Thousands, T in Millions		3 Months Ended		6 Months Ended
	Feb. 01, 2016 USD ($)	Feb. 28, 2017 USD ($) Tons T	Feb. 29, 2016 USD ($)	Feb. 28, 2017 USD ($) Tons T	Feb. 29, 2016 USD ($)	Feb. 01, 2096 USD ($)	Aug. 31, 2016 USD ($)
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (35,800)	$ (28,004)	$ (76,128)	$ (59,366)
Cost Method Investments		130,148		130,148			$ 127,577
Investments		$ 3,802,379		$ 3,802,379			3,795,976
CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments	$ 2,800,000
Ownership percentage	11.40%
Supply agreement, term	80 years
Maximum annual granular urea eligible for purchase | T		1.1		1.1
Maximum annual UAN eligible for purchase | Tons		580,000		580,000
Equity Method Investments		$ 2,784,459		$ 2,784,459			2,796,323
Ventura Foods, LLC
Schedule of Equity Method Investments [Line Items]
Equity Method Investments		370,089		370,089			369,487
TEMCO, LLC
Schedule of Equity Method Investments [Line Items]
Equity Method Investments		41,472		41,472			44,578
Ardent Mills LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments		$ 202,671		$ 202,671			194,986
Cargill, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of joint venture partner		50.00%		50.00%
Nitrogen Production [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (21,557)	(11,855)	$ (36,253)	(11,855)
Foods [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (5,561)	(14,450)	$ (18,930)	(35,527)
Foods [Member] | Ventura Foods, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%		50.00%
Equity value exceeding carrying value		$ 12,900		$ 12,900
Corporate and Other
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (4,741)	(1,690)	$ (10,425)	(7,576)
Corporate and Other | Ardent Mills LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage		12.00%		12.00%
Number of parent companies		3		3
Ag [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (3,455)	$ 1,355	$ (8,872)	$ (2,221)
Ag [Member] | TEMCO, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%		50.00%
Scenario, Forecast [Member] | Nitrogen Production [Member] | CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments						$ 0
Miscellaneous Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments		$ 273,540		$ 273,540			$ 263,025