Investments - Schedule of Short-Term and Long-Term Marketable Securities (Details) - USD ($) $ in Millions	Jul. 31, 2025	Jan. 31, 2025
Investments, Debt and Equity Securities [Abstract]
Due within 1 year	$ 1,527	$ 2,081
Due in 1 year through 5 years	3,471	3,098
Due in 5 years through 10 years	9	5
Fair value of marketable securities	$ 5,007	$ 5,184