Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2025	Oct. 31, 2024	Jan. 31, 2025
Investment Holdings [Line Items]
Interest income from marketable securities	$ 139	$ 145	$ 457	$ 522
Strategic investments	6,410		6,410		$ 4,852
Privately held equity securities
Investment Holdings [Line Items]
Upward adjustments	456	22	490	182
Downward adjustments	190	$ 245	335	$ 435
Variable Interest Entity, Not Primary Beneficiary
Investment Holdings [Line Items]
Strategic investments	$ 281		$ 281		$ 484