Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands		3 Months Ended	12 Months Ended
	Feb. 01, 2016 USD ($)	Aug. 31, 2015 USD ($) Refineries	Aug. 31, 2015 USD ($) Refineries	Aug. 31, 2014 USD ($)	Aug. 31, 2013 USD ($)	Sep. 30, 2015	Nov. 29, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Income taxes			$ (12,165)	$ 48,296	$ 89,666
Finite-Lived Intangible Assets, Net
Number of Refineries | Refineries		2	2
Minimum | Subsidiaries
Income Taxes [Abstract]
Subsidiaries Ownership Percentage			80.00%
Minimum | Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net
Finite-Lived Intangible Asset, Useful Life			2 years
Minimum | Major Maintenance Activities Requiring Shutdown
Finite-Lived Intangible Assets, Net
Finite-Lived Intangible Asset, Useful Life			2 years
Minimum | Land and Land Improvements
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			15 years
Minimum | Building
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			20 years
Minimum | Machinery, Equipment, Office and Other
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			5 years
Minimum | Property, Plant and Equipment, Other Types [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			3 years
Maximum | Other Intangible Assets [Member]
Finite-Lived Intangible Assets, Net
Finite-Lived Intangible Asset, Useful Life			30 years
Maximum | Major Maintenance Activities Requiring Shutdown
Finite-Lived Intangible Assets, Net
Finite-Lived Intangible Asset, Useful Life			4 years
Maximum | Land and Land Improvements
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			20 years
Maximum | Building
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			40 years
Maximum | Machinery, Equipment, Office and Other
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			20 years
Maximum | Property, Plant and Equipment, Other Types [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Property, Plant and Equipment, Useful Life			10 years
National Cooperative Refinery Association
Derivative Instruments, Gain (Loss) [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage		88.90%	88.90%				74.40%
Subsequent Event [Member] | National Cooperative Refinery Association
Derivative Instruments, Gain (Loss) [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage						100.00%
Application Of Leases And Lease Arrangements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Income taxes		$ 16,000
Scenario, Forecast [Member] | CF Nitrogen LLC [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Supply agreement, term	80 years
Payments to Acquire Equity Method Investments	$ 2,800,000
Equity Method Investment, Ownership Percentage	11.40%