Income Taxes - Summary of Provision for Income Taxes Related to Continuing Operations (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Current
Federal	$ (35)	$ (4)	$ (11)
State	(2)	(7)	(11)
Foreign	25	31	34
Total current income tax expense (benefit)	(12)	20	12
Deferred	(26)	(42)	18
Income tax expense (benefit)	$ (38)	$ (22)	$ 30

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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Amount of current foreign income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

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Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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