Organization, Basis of Presentation and Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2019	Aug. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Intangible assets with indefinite useful lives		$ 0
Reclassification of tax effects to capital reserves		0
Accumulated Other Comprehensive Loss
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification of tax effects to capital reserves		(4,706)	$ (26,992)
Capital Reserves
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification of tax effects to capital reserves	$ 27,000	$ 4,706
Minimum | Major Maintenance Activities
Derivative Instruments, Gain (Loss) [Line Items]
Expenditures of turnarounds, capitalization period		2 years
Minimum | Other Intangible Assets
Derivative Instruments, Gain (Loss) [Line Items]
Expenditures of turnarounds, capitalization period		2 years
Minimum | Land improvements
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		15 years
Minimum | Buildings
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		20 years
Minimum | Machinery and equipment
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		5 years
Minimum | Office equipment and other
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		3 years
Maximum | Major Maintenance Activities
Derivative Instruments, Gain (Loss) [Line Items]
Expenditures of turnarounds, capitalization period		5 years
Maximum | Other Intangible Assets
Derivative Instruments, Gain (Loss) [Line Items]
Expenditures of turnarounds, capitalization period		30 years
Maximum | Land improvements
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		20 years
Maximum | Buildings
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		40 years
Maximum | Machinery and equipment
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		20 years
Maximum | Office equipment and other
Derivative Instruments, Gain (Loss) [Line Items]
Property, plant and equipment, useful life		10 years
Low range [Member]
Derivative Instruments, Gain (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 240,000
High range [Member]
Derivative Instruments, Gain (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 280,000