Goodwill and Intangible Assets - Schedule of Intangible Assets with Finite Lives (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	$ 133	$ 127
Accumulated Amortization	(33)	(24)
Net Intangible Assets, finite lives	100	103
Developed Technologies [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	62	60
Accumulated Amortization	(12)	(8)
Net Intangible Assets, finite lives	50	52
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	11	11
Accumulated Amortization	(1)	(1)
Net Intangible Assets, finite lives	10	10
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value, finite lives	60	56
Accumulated Amortization	(20)	(15)
Net Intangible Assets, finite lives	$ 40	$ 41