Goodwill and Other Intangibles - Additional Information (Details)	3 Months Ended		6 Months Ended
	Mar. 31, 2020 USD ($) ReportableSegment	Mar. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Schedule Of Goodwill And Finite Lived Intangible Assets [Line Items]
Number of reportable segments | ReportableSegment	5
Impairment	$ 530,000,000	$ 0	$ 530,000,000	$ 0
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense recognized on intangible assets	21,000,000	$ 21,000,000	42,000,000	$ 43,000,000
Expected future amortization expense [Abstract]
2020 (includes six months actual and six months estimated)	85,000,000		85,000,000
2021	85,000,000		85,000,000
2022	84,000,000		84,000,000
2023	84,000,000		84,000,000
2024	70,000,000		70,000,000
Trademarks and Trade Names [Member]
Intangible Assets, Net [Abstract]
Impairment			$ 0
Minimum [Member] | Trademarks and Trade Names [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			3 years
Minimum [Member] | Intellectual Property [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			5 years
Minimum [Member] | Customer and Supplier Relationships [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			3 years
Maximum [Member] | Trademarks and Trade Names [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			25 years
Maximum [Member] | Intellectual Property [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			25 years
Maximum [Member] | Customer and Supplier Relationships [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			24 years
Former Reporting Unit [Member]
Schedule Of Goodwill And Finite Lived Intangible Assets [Line Items]
Impairment	0
New Reporting Unit [Member]
Schedule Of Goodwill And Finite Lived Intangible Assets [Line Items]
Impairment	$ 530,000,000		$ 530,000,000