Derivative Instruments and Hedging Activities - Location and Amount of Gains and Losses Gross of Tax on Derivative Instruments and Related Hedge Items (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	$ (118)	$ 90	$ 193
Foreign currency exchange derivatives | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	(16)	10	(6)
Foreign currency exchange derivatives | Net financing charges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	(103)	85	174
Foreign currency exchange derivatives | Selling, general and administrative
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	0	0	(2)
Foreign currency exchange derivatives | Income tax provision
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	0	0	(1)
Interest rate swaps | Net financing charges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	1	0	0
Equity swap | Selling, general and administrative
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	0	(5)	28
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	15	21	(2)
Amount of gain (loss) reclassified from AOCI into income	(12)	16	14
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	(13)	26	15
Amount of gain (loss) reclassified from AOCI into income	(4)	25	11
Cash Flow Hedging | Commodity derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	1	(21)	4
Amount of gain (loss) reclassified from AOCI into income	(8)	(7)	3
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	27	16	(21)
Amount of gain (loss) reclassified from AOCI into income	$ 0	$ (2)	$ 0