Other income net - Summary of Other Income (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Revenue [abstract]
Interest income	$ 38	$ 232

The amount of income arising from interest.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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