Fair Value Measurements (Details) - USD ($) $ in Thousands	Oct. 31, 2025	Jan. 31, 2025
Financial Assets:
Cash equivalents	$ 668,775	$ 867,001
Marketable securities	6,727,428	6,442,329
Publicly held equity securities included in strategic investments	98,260	35,280
Privately held debt securities included in strategic investments	3,957	4,450
Total financial assets	7,498,420	7,349,060
U.S. government agency securities
Financial Assets:
Marketable securities	4,950,856	4,415,930
Agency bonds
Financial Assets:
Marketable securities	968,404	1,174,484
Corporate and other debt securities
Financial Assets:
Marketable securities	750,925	720,795
Treasury bills
Financial Assets:
Marketable securities	54,247	110,279
Commercial paper
Financial Assets:
Marketable securities	2,996	20,841
Money market funds
Financial Assets:
Cash equivalents	626,789	825,044
Treasury bills
Financial Assets:
Cash equivalents	4,998	17,965
Agency bonds
Financial Assets:
Cash equivalents	36,988	23,992
Level 1
Financial Assets:
Cash equivalents	626,789	825,044
Marketable securities	0	0
Publicly held equity securities included in strategic investments	98,260	35,280
Privately held debt securities included in strategic investments	0	0
Total financial assets	725,049	860,324
Level 1 | U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Level 1 | Agency bonds
Financial Assets:
Marketable securities	0	0
Level 1 | Corporate and other debt securities
Financial Assets:
Marketable securities	0	0
Level 1 | Treasury bills
Financial Assets:
Marketable securities	0	0
Level 1 | Commercial paper
Financial Assets:
Marketable securities	0	0
Level 1 | Money market funds
Financial Assets:
Cash equivalents	626,789	825,044
Level 1 | Treasury bills
Financial Assets:
Cash equivalents	0	0
Level 1 | Agency bonds
Financial Assets:
Cash equivalents	0	0
Level 2
Financial Assets:
Cash equivalents	41,986	41,957
Marketable securities	6,727,428	6,442,329
Publicly held equity securities included in strategic investments	0	0
Privately held debt securities included in strategic investments	0	0
Total financial assets	6,769,414	6,484,286
Level 2 | U.S. government agency securities
Financial Assets:
Marketable securities	4,950,856	4,415,930
Level 2 | Agency bonds
Financial Assets:
Marketable securities	968,404	1,174,484
Level 2 | Corporate and other debt securities
Financial Assets:
Marketable securities	750,925	720,795
Level 2 | Treasury bills
Financial Assets:
Marketable securities	54,247	110,279
Level 2 | Commercial paper
Financial Assets:
Marketable securities	2,996	20,841
Level 2 | Money market funds
Financial Assets:
Cash equivalents	0	0
Level 2 | Treasury bills
Financial Assets:
Cash equivalents	4,998	17,965
Level 2 | Agency bonds
Financial Assets:
Cash equivalents	36,988	23,992
Level 3
Financial Assets:
Cash equivalents	0	0
Marketable securities	0	0
Publicly held equity securities included in strategic investments	0	0
Privately held debt securities included in strategic investments	3,957	4,450
Total financial assets	3,957	4,450
Level 3 | U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Level 3 | Agency bonds
Financial Assets:
Marketable securities	0	0
Level 3 | Corporate and other debt securities
Financial Assets:
Marketable securities	0	0
Level 3 | Treasury bills
Financial Assets:
Marketable securities	0	0
Level 3 | Commercial paper
Financial Assets:
Marketable securities	0	0
Level 3 | Money market funds
Financial Assets:
Cash equivalents	0	0
Level 3 | Treasury bills
Financial Assets:
Cash equivalents	0	0
Level 3 | Agency bonds
Financial Assets:
Cash equivalents	$ 0	$ 0