Debt and Financing Activities - Long-Term Debt Narrative (Details) - USD ($) $ in Millions			6 Months Ended
	Jun. 16, 2023	Jun. 15, 2023	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2023
Debt Instrument [Line Items]
Long-term debt			$ 5,600		$ 5,600
Current portion of long-term debt			49		968
Repayments of long-term debt			271	$ 4
Purchase of U.S. government obligations for the satisfaction and discharge of long-term debt			647	$ 0
Debt outstanding			5,584		5,594
Gain on debt extinguishment			$ 9
Term Loan
Debt Instrument [Line Items]
Redemption price percentage of principal (percent)			101.00%
Term Loan | Minimum
Debt Instrument [Line Items]
Debt instrument, redemption period (in days)			10 days
Term Loan | Maximum
Debt Instrument [Line Items]
Debt instrument, redemption period (in days)			60 days
4.90% Notes due July 15, 2028 | Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		4.90%	4.90%
Debt principal amount		$ 400
Proceeds from debt issuance		$ 397
Debt outstanding			$ 399		0
5.10% Notes due July 15, 2033 | Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		5.10%	5.10%
Debt principal amount		$ 600
Proceeds from debt issuance		$ 592
Debt outstanding			$ 596		0
3.80% Notes due March 15, 2024 | Term Loan
Debt Instrument [Line Items]
Interest rate on debt instrument (percent)		3.80%	3.80%
Redemption price percentage of principal (percent)	98.75%
Repayments of long-term debt	$ 268
Debt principal redeemed	271
Purchase of U.S. government obligations for the satisfaction and discharge of long-term debt	$ 647
Debt outstanding			$ 0		$ 918