SEC Schedule, Article 12-09, Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Accounts Receivable - Allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 24	$ 15	$ 21
Provision during period	23	13	9
Allowance adjustments	(7)	(5)	(15)
Currency translation	0	1	0
SEC Schedule, 12-09, valuation allowances and reserves, amount, ending balance	40	24	15
Deferred Tax Assets - Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	1,769	1,655	1,662
Provision during period	828	90	(61)
Allowance adjustments	17	24	54
SEC Schedule, 12-09, valuation allowances and reserves, amount, ending balance	$ 2,614	$ 1,769	$ 1,655