Other Operating Income (Expense), Net and Other Non-Operating Income (Expense), Net - Schedule of Other Operating Income (Expense), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment
Finance charges	$ 15	$ 16	$ 17
Gains on sales of fixed assets, net	25	22	61
Foreign currency transaction gains (losses)	0	2	7
Cylinder deposit income	17	17	23
Interest and interest-related income	12	11	6
Other, net	13	(6)	18
Total other operating income (expense), net	$ 82	$ 62	132
Building
Property, Plant and Equipment
Gains on sales of fixed assets, net			$ 15