Restructuring Activities - Narrative (Details) - Employee Severance $ in Millions	12 Months Ended
Sep. 30, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other benefits paid to employees	$ 12
Expected costs for restructuring activities	$ 1

Amount of other expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses associated with a discontinued operation or an asset retirement obligation.

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