Fair Value Measurements (Details) - USD ($) $ in Thousands	Apr. 30, 2022	Jan. 31, 2022
Financial Assets:
Marketable securities	$ 4,318,974	$ 4,356,446
Commercial paper
Financial Assets:
Marketable securities	34,881	28,723
Agency bonds
Financial Assets:
Marketable securities	594,397	629,609
Corporate and other debt securities
Financial Assets:
Marketable securities	285,251	280,927
U.S. government agency securities
Financial Assets:
Marketable securities	3,146,058	3,027,509
Fair Value, Recurring Basis
Financial Assets:
Cash equivalents	1,151,957	796,967
Marketable securities	4,318,974	4,356,446
Publicly held equity securities included in strategic investments	133,013	168,784
Total financial assets	5,618,562	5,336,725
Fair Value, Recurring Basis | Commercial paper
Financial Assets:
Marketable securities	34,881	28,723
Fair Value, Recurring Basis | Agency bonds
Financial Assets:
Marketable securities	594,397	629,609
Fair Value, Recurring Basis | Corporate and other debt securities
Financial Assets:
Marketable securities	285,251	280,927
Fair Value, Recurring Basis | U.S. government agency securities
Financial Assets:
Marketable securities	3,146,058	3,027,509
Fair Value, Recurring Basis | Treasury bills
Financial Assets:
Marketable securities	258,387	389,678
Fair Value, Recurring Basis | Certificates of deposit
Financial Assets:
Certificates of deposit included in other assets, noncurrent	274	297
Fair Value, Recurring Basis | Privately held debt securities included in strategic investments
Financial Assets:
Marketable securities	14,344	14,231
Fair Value, Recurring Basis | Money market funds
Financial Assets:
Cash equivalents	1,054,691	688,722
Fair Value, Recurring Basis | Treasury bills
Financial Assets:
Cash equivalents	92,477	107,496
Fair Value, Recurring Basis | Corporate debt securities
Financial Assets:
Cash equivalents	783	749
Fair Value, Recurring Basis | U.S. government agency securities
Financial Assets:
Cash equivalents	4,006
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1
Financial Assets:
Cash equivalents	1,054,691	688,722
Marketable securities	0	0
Publicly held equity securities included in strategic investments	133,013	168,784
Total financial assets	1,187,704	857,506
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Commercial paper
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Agency bonds
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Corporate and other debt securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Treasury bills
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Certificates of deposit
Financial Assets:
Certificates of deposit included in other assets, noncurrent	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Privately held debt securities included in strategic investments
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Money market funds
Financial Assets:
Cash equivalents	1,054,691	688,722
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Treasury bills
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | Corporate debt securities
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 1 | U.S. government agency securities
Financial Assets:
Cash equivalents	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2
Financial Assets:
Cash equivalents	97,266	108,245
Marketable securities	4,318,974	4,356,446
Publicly held equity securities included in strategic investments		0
Total financial assets	4,416,514	4,464,988
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Commercial paper
Financial Assets:
Marketable securities	34,881	28,723
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Agency bonds
Financial Assets:
Marketable securities	594,397	629,609
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Corporate and other debt securities
Financial Assets:
Marketable securities	285,251	280,927
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | U.S. government agency securities
Financial Assets:
Marketable securities	3,146,058	3,027,509
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Treasury bills
Financial Assets:
Marketable securities	258,387	389,678
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Certificates of deposit
Financial Assets:
Certificates of deposit included in other assets, noncurrent	274	297
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Privately held debt securities included in strategic investments
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Money market funds
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Treasury bills
Financial Assets:
Cash equivalents	92,477	107,496
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | Corporate debt securities
Financial Assets:
Cash equivalents	783	749
Fair Value, Recurring Basis | Fair Value, Inputs, Level 2 | U.S. government agency securities
Financial Assets:
Cash equivalents	4,006
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3
Financial Assets:
Cash equivalents	0	0
Marketable securities	0	0
Publicly held equity securities included in strategic investments		0
Total financial assets	14,344	14,231
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Commercial paper
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Agency bonds
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Corporate and other debt securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Treasury bills
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Certificates of deposit
Financial Assets:
Certificates of deposit included in other assets, noncurrent	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Privately held debt securities included in strategic investments
Financial Assets:
Marketable securities	14,344	14,231
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Money market funds
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Treasury bills
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | Corporate debt securities
Financial Assets:
Cash equivalents	0	$ 0
Fair Value, Recurring Basis | Fair Value, Inputs, Level 3 | U.S. government agency securities
Financial Assets:
Cash equivalents	$ 0