Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2025	Jul. 31, 2024	Jan. 31, 2025
Investment Holdings [Line Items]
Interest income from marketable securities	$ 150	$ 181	$ 319	$ 377
Strategic investments	5,085		5,085		$ 4,852
Privately held equity securities
Investment Holdings [Line Items]
Upward adjustments	13	44	34	160
Downward adjustments	85	$ 51	145	$ 190
Variable Interest Entity, Not Primary Beneficiary
Investment Holdings [Line Items]
Strategic investments	$ 571		$ 571		$ 484