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		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	$ 60	$ 9	$ 12	$ (72)
Foreign currency exchange derivatives | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	2	(6)	(3)	(8)
Foreign currency exchange derivatives | Net financing charges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	59	15	16	(64)
Foreign currency exchange derivatives | Selling, general and administrative
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income on derivative	(1)	0	(1)	0
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Other comprehensive income (loss), cash flow hedge, gain (loss), before reclassification and tax	29	17	(18)	0
Amount of gain (loss) reclassified from AOCI into income	(3)	(7)	(7)	(4)
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	15	9	2	(12)
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	(2)	(5)	(3)	4
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	3	1	7
Cash Flow Hedging | Commodity derivatives | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) reclassified from AOCI into income	(1)	(2)	(4)	(8)
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	14	5	(21)	5
Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses) related to net investment hedges recorded in other comprehensive income	$ 98	$ (60)	$ (47)	$ (329)