Intangible Assets - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Decrease in Growth Rate Resulting In An Estimated Fair Value Below The Carrying Value	14000.00%
Fair value in excess of carrying amount, percent	5.00%
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	$ 0	$ 2
Increase in Discount Rate Resulting In An Estimated Fair Value Below The Carrying Value	5000.00%
Acquired Technology and Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	$ 0	2
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	$ 0	$ 0