Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2020	Oct. 01, 2019	Sep. 30, 2019
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	$ 3,152		$ 3,156
Accumulated amortization	(765)		(598)
Finite-lived intangible assets, net	2,387		2,558
Indefinite-Lived Intangible Assets (Excluding Goodwill And Accumulated Impairment)	333		333
Intangible assets, net	2,720	$ 2,889	2,891
Acquired technology and patents
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	960		960
Accumulated amortization	(394)		(308)
Finite-lived intangible assets, net	566		652
Customer relationships and other intangibles
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	2,150		2,154
Accumulated amortization	(355)		(279)
Finite-lived intangible assets, net	1,795		1,875
Trademarks and trade names
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	42		42
Accumulated amortization	(16)		(11)
Finite-lived intangible assets, net	26		31
Acquired technology and patents
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill And Accumulated Impairment)	0		0
Customer relationships and other intangibles
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill And Accumulated Impairment)	0		0
Trademarks and trade names
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill And Accumulated Impairment)	333		333
Trademarks and trade names
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net	359		364
Customer relationships and other intangibles
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net	1,795		1,875
Acquired technology and patents
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net	$ 566		$ 652