Income Taxes - Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits at beginning of period	$ 1,463	$ 1,399	$ 1,523
Additions based on tax positions related to prior years	33	10	0
Reductions based on tax positions related to prior years	(43)	(2)	(26)
Additions based on tax positions related to current year	97	64	21
Reductions based on settlements	(13)	(8)	(96)
Reductions based on the lapse of the applicable statutes of limitations	(7)	(2)	(16)
Exchange rate fluctuations	2	2	(7)
Unrecognized tax benefits at end of period	$ 1,532	$ 1,463	$ 1,399

Unrecognized Tax Benefits, Increase (Decrease) Resulting from Foreign Currency Translation

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Name Accounting Standards Codification
-Section 50
-Paragraph 15A
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Name Accounting Standards Codification
-Section 45
-Paragraph 10B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482525/740-10-45-10B

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- Definition

Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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- Definition

Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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- Definition

Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

+ References

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-SubTopic 10
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