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Additional Financial Information - Additional Information (Detail) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares	Dec. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Nov. 09, 2023 $ / shares
Dividends Payable [Line Items]
Interest payments	$ 33	$ 25
Income and withholding taxes paid	39	45
Noncash acquisition activities	18
Net loss (gain) on divestitures	$ 17	41	$ 41	$ 0	$ 0
Debt instrument, covenant, total indebtedness to EBITDA ratio	3.50
Dividends paid	$ 89	$ 84
Dividends paid (in dollars per share) \| $ / shares	$ 0.17
Common Stock
Dividends Payable [Line Items]
Cash dividends declared (in dollars per share) \| $ / shares						$ 0.17