Income Taxes - Deferred Taxes (Details) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Other noncurrent assets	$ 199	$ 506
Other noncurrent liabilities	(206)	(217)
Net deferred tax liabilities	$ (7)
Net deferred tax asset		$ 289

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences with jurisdictional netting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
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-Section 45
-Paragraph 6
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Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.

+ References

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=116821951&loc=d3e31931-109318

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
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