Cash Equivalents and Investments - Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Millions	Oct. 31, 2025	Jan. 31, 2025
Cash and Cash Equivalents [Line Items]
Total cash equivalents	$ 422	$ 248
Total short-term investments	1,818	2,114
Total	2,240	2,362
U.S. treasury securities | Level 2
Cash and Cash Equivalents [Line Items]
Total short-term investments	1,517	1,788
Corporate debt securities | Level 2
Cash and Cash Equivalents [Line Items]
Total short-term investments	239	281
Certificates of deposit | Level 2
Cash and Cash Equivalents [Line Items]
Total short-term investments	62	45
Money market funds | Level 1
Cash and Cash Equivalents [Line Items]
Total cash equivalents	422	225
Certificates of deposit | Level 2
Cash and Cash Equivalents [Line Items]
Total cash equivalents	$ 0	$ 23