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	Jul. 31, 2025	Jan. 31, 2025
Cash and Cash Equivalents [Line Items]
Total cash equivalents	$ 694	$ 248
Total short-term investments	1,982	2,114
Total	2,676	2,362
U.S. treasury securities | Level 2
Cash and Cash Equivalents [Line Items]
Total short-term investments	1,680	1,788
Corporate debt securities | Level 2
Cash and Cash Equivalents [Line Items]
Total short-term investments	249	281
Certificates of deposit | Level 2
Cash and Cash Equivalents [Line Items]
Total short-term investments	53	45
Money market funds | Level 1
Cash and Cash Equivalents [Line Items]
Total cash equivalents	654	225
Certificates of deposit | Level 2
Cash and Cash Equivalents [Line Items]
Total cash equivalents	34	23
U.S. treasury securities | Level 2
Cash and Cash Equivalents [Line Items]
Total cash equivalents	$ 6	$ 0