Share-based Compensation - Schedule of Share-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	$ 820	$ 1,070	$ 326
Less: income tax effect	144	210	48
Net share-based compensation cost	676	860	278
Cost of sales
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	26	41	12
Research and development
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	576	728	212
Selling, general and administrative
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	$ 218	$ 301	$ 102

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479830/718-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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