Cash and Cash Equivalents and Investments in Marketable Securities - Summary of Contractual Maturities of Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions		Mar. 31, 2024	Mar. 31, 2023
Available-for-sale debt securities, Amortized cost
Due within 1 Year, Amortized cost		$ 52
Due after 1 Year through 5 Years, Amortized cost		309
Due after 5 Years through 10 Years, Amortized cost		471
Due after 10 Years, Amortized cost		449
Mortgage-backed and asset-backed securities, Amortized cost	[1]	341
Available-for-sale debt securities, Amortized cost		$ 1,622	$ 1,584
Debt Securities, Available-for-sale, Maturity Allocation [Extensible List]		us-gaap:DebtSecuritiesMaturityAllocationContractualMaturityMember
Available-for-sale debt securities, Fair value
Due within 1 Year, Fair value		$ 51
Due after 1 Year through 5 Years, Fair value		293
Due after 5 Years through 10 Years, Fair value		442
Due after 10 Years, Fair value		360
Mortgage-backed and asset-backed securities, Fair value	[1]	322
Total, Fair value		$ 1,468	$ 1,454
Debt Securities, Available-for-sale, Maturity Allocation [Extensible List]		us-gaap:DebtSecuritiesMaturityAllocationContractualMaturityMember

[1] Mortgage-backed and asset-backed securities are shown separately from other maturity groupings as these securities have multiple maturity dates.