Investments - Narrative (Details) T in Millions		3 Months Ended			6 Months Ended
	Feb. 01, 2016 USD ($)	Feb. 29, 2016 USD ($) T Tons	Feb. 28, 2015 USD ($)	Nov. 30, 2014 USD ($)	Feb. 29, 2016 USD ($) T Tons	Feb. 28, 2015 USD ($)	Feb. 01, 2096 USD ($)	Aug. 31, 2015
Schedule of Equity Method Investments [Line Items]
Payments for Repurchase of Redeemable Noncontrolling Interest					$ (153,022,000)	$ (65,981,000)
Equity (income) loss from investments		$ (28,004,000)	$ (24,169,000)		(59,366,000)	(48,798,000)
Payments to Acquire Other Investments				$ 315,000,000	0	315,000,000
Short-term Investments		$ 0			$ 0
CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments	$ 2,800,000,000
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
Cargill, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of joint venture partner		50.00%			50.00%
Crack Spread Contingent Payment [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Business, Contingent Consideration Paid		$ 2,600,000
Energy [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (1,364,000)	(736,000)		$ (2,187,000)	(1,076,000)
Energy [Member] | National Cooperative Refinery Association [Member]
Schedule of Equity Method Investments [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage		100.00%			100.00%			88.90%
Payments for Repurchase of Redeemable Noncontrolling Interest					$ (153,000,000)	(66,000,000)
Accrued liability for contingent crack spread payments related to purchase of noncontrolling interest		$ 24,155,000			24,155,000
Nitrogen Production [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments			0		(11,855,000)	0
Nitrogen Production [Member] | CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		(11,855,000)
Equity Method Investments		2,800,000,000			2,800,000,000
Corporate and Other
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (16,140,000)	(18,990,000)		$ (43,103,000)	(43,259,000)
Corporate and Other | Ardent Mills [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage		12.00%			12.00%
Equity Method Investments		$ 190,800,000			$ 190,800,000
Corporate and Other | Ventura Foods, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%			50.00%
Equity Method Investments		$ 355,800,000			$ 355,800,000
Equity value exceeding carrying value		12,900,000			12,900,000
Ag [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ 1,355,000	$ (4,443,000)		$ (2,221,000)	$ (4,463,000)
Ag [Member] | TEMCO, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%			50.00%
Equity Method Investments		$ 53,500,000			$ 53,500,000
Scenario, Forecast [Member] | Nitrogen Production [Member] | CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments							$ 0