Derivative Instruments and Hedging Activities - Location and Amount of Gains and Losses on Derivative Instruments and Related Hedge Items (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	$ 72	$ 18	$ (22)	$ 31
Foreign currency exchange derivatives \| Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	0	(4)	(8)	(7)
Foreign currency exchange derivatives \| Net financing charges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	71	20	(13)	36
Foreign currency exchange derivatives \| Selling, general and administrative
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	1	2	(1)	2
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	0	6	18	(12)
Amount of gain (loss) reclassified from AOCI into income	6	4	8	(3)
Cash Flow Hedging \| Foreign currency exchange derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	0	2	15	4
Cash Flow Hedging \| Foreign currency exchange derivatives \| Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI into income	4	4	7	1
Cash Flow Hedging \| Commodity derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	0	4	3	5
Cash Flow Hedging \| Commodity derivatives \| Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI into income	2	0	1	(4)
Cash Flow Hedging \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	0	0	0	(21)
Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses) related to net investment hedges recorded in other comprehensive income	$ (269)	$ 44	$ (162)	$ (3)

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