Derivative Instruments and Hedging Activities - Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022
Derivatives, Fair Value [Line Items]
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Foreign currency exchange derivatives
Derivatives, Fair Value [Line Items]
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
Total assets	$ 34	$ 20
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Derivatives and Hedging Activities Designated as Hedging Instruments under ASC 815 | Foreign currency exchange derivatives
Derivatives, Fair Value [Line Items]
Derivative asset, current	$ 30	$ 17
Total assets	30	17
Derivative liability, current	$ 8	$ 20
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other noncurrent liabilities	Other noncurrent liabilities
Total liabilities	$ 144	$ 831
Derivatives and Hedging Activities Designated as Hedging Instruments under ASC 815 | Foreign currency exchange derivatives | Noncurrent assets
Derivatives, Fair Value [Line Items]
Derivative liability, noncurrent	6	2
Derivatives and Hedging Activities Designated as Hedging Instruments under ASC 815 | Foreign currency exchange derivatives | Long-Term Debt And Lease Obligation
Derivatives, Fair Value [Line Items]
Derivative liability, noncurrent	130	809
Derivatives and Hedging Activities Not Designated as Hedging Instruments under ASC 815 | Foreign currency exchange derivatives
Derivatives, Fair Value [Line Items]
Derivative asset, current	4	3
Total assets	4	3
Derivative liability, current	$ 0	$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other noncurrent liabilities	Other noncurrent liabilities
Total liabilities	$ 0	$ 1
Derivatives and Hedging Activities Not Designated as Hedging Instruments under ASC 815 | Foreign currency exchange derivatives | Noncurrent assets
Derivatives, Fair Value [Line Items]
Derivative liability, noncurrent	0	1
Derivatives and Hedging Activities Not Designated as Hedging Instruments under ASC 815 | Foreign currency exchange derivatives | Long-Term Debt And Lease Obligation
Derivatives, Fair Value [Line Items]
Derivative liability, noncurrent	$ 0	$ 0