Debt and Financing Activities - Long-Term Debt (Details) € in Millions, $ in Millions											12 Months Ended
	Feb. 15, 2024	Jun. 16, 2023 USD ($)	Jun. 15, 2023 USD ($)	Mar. 15, 2023 USD ($)	Feb. 15, 2023 USD ($)	Dec. 15, 2022 USD ($)	Aug. 12, 2021 USD ($)	Jul. 23, 2021 USD ($)	Jul. 17, 2021 USD ($)	Jul. 17, 2021 EUR (€)	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
Debt Instrument [Line Items]
Debt outstanding											$ 5,600	$ 5,600
Current portion of long-term debt											50	968
Retired and redeemed outstanding principal amount											288	1,274	$ 1,648
Purchase of U.S. government obligations for the satisfaction and discharge of long-term debt											647	0	0
Loss on debt extinguishment											0	0	191
Payments for debt extinguishments											$ 0	$ 0	184
Loans payable
Debt Instrument [Line Items]
Redemption price (percent)							101.00%
4.90% Notes Due July 15, 2028 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)			4.90%								4.90%
Aggregate principal amount			$ 400
Proceeds from issuance, net			$ 397
5.10% Notes Due July 15, 2033 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)			5.10%								5.10%
Aggregate principal amount			$ 600
Proceeds from issuance, net			$ 592
3.80% Notes due March 15, 2024 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)			3.80%					3.80%			3.80%
Redemption price (percent)		98.75%
Retired and redeemed outstanding principal amount		$ 268
Debt Instrument, repurchased face amount		271
Purchase of U.S. government obligations for the satisfaction and discharge of long-term debt		$ 647
Loss on debt extinguishment											$ (9)
5.25% Notes Due 2026 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)					5.25%
Aggregate principal amount					$ 500
Proceeds from issuance, net					$ 497
Redemption price (percent)	100.00%
1.30% Notes due August 15, 2026 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)							1.30%				1.30%
Aggregate principal amount							$ 500
Proceeds from issuance, net							$ 495
2.85% Notes Due March 15, 2023 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)				2.85%				2.85%
Retired and redeemed outstanding principal amount				$ 360
2.70% Notes Due December 15, 2022 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)						2.70%
Retired and redeemed outstanding principal amount						$ 400
0.63% Euro Notes Due August 17, 2021 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)									0.63%	0.63%
Retired and redeemed outstanding principal amount									$ 709	€ 600
7.65% Debentures due March 1, 2027 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)								7.65%			7.65%
3.95% Notes due February 16, 2028 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)								3.95%			3.95%
4.75% Notes due May 30, 2029 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)								4.75%			4.75%
6.00% Notes due March 1, 2041 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)								6.00%			6.00%
4.88% Notes due March 15, 2044 | Loans payable
Debt Instrument [Line Items]
Interest rate on debt instruments (percent)								4.88%			4.88%
Tender Offer Notes | Loans payable
Debt Instrument [Line Items]
Redemption price (percent)								100.00%
Debt Instrument, repurchased face amount								$ 922
Loss on debt extinguishment													191
Debt instrument, repurchase amount								1,100
Payments for debt extinguishments								182
Accrued and unpaid interest								$ 14
Debt premiums													182
Write-off of unamortized debt issuance costs and transaction fees													$ 9