Share-based Compensation - Schedule of Share-Based Compensation Cost (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	$ 1,052	$ 820	$ 1,070
Less: income tax effect	168	144	210
Net share-based compensation cost	884	676	860
Cost of sales
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	29	26	41
Research and development
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	762	576	728
Selling, general and administrative
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Pre-tax share-based compensation cost	$ 261	$ 218	$ 301

Share-Based Payment Arrangement, Expense, Tax Benefit, Net

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479983/718-10-S45-1

Reference 2: 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 3: 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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- Definition

Amount, after tax, of expense for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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