Restructuring Activities - Summary of Amount of Restructuring Severance Expense Related to Program (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Restructuring Cost and Reserve [Line Items]
Severance expense (income)	$ 4	$ 3	$ 13	$ 23
Utilization (cash paid)	(4)	(3)	(18)	(7)
2025 Restructuring program
Restructuring Cost and Reserve [Line Items]
Severance expense (income)	4	0	15	0
Utilization (cash paid)	(2)	0	(7)	0
2023 Restructuring program
Restructuring Cost and Reserve [Line Items]
Severance expense (income)	0	3	(2)	23
Utilization (cash paid)	$ (2)	$ (3)	$ (11)	$ (7)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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