Fair Value Measurements (Details) - USD ($) $ in Thousands	Jul. 31, 2024	Jan. 31, 2024
Financial Assets:
Marketable securities	$ 5,980,575	$ 5,404,233
Privately held debt securities included in strategic investments	4,403	3,828
Commercial paper
Financial Assets:
Marketable securities	19,636	41,564
Agency bonds
Financial Assets:
Marketable securities	1,768,712	1,666,683
Corporate and other debt securities
Financial Assets:
Marketable securities	712,223	663,159
U.S. government agency securities
Financial Assets:
Marketable securities	3,359,559	3,004,842
Fair Value, Recurring Basis
Financial Assets:
Cash equivalents	1,013,589	974,599
Marketable securities	5,980,575	5,404,233
Publicly held equity securities included in strategic investments	26,880	23,160
Privately held debt securities included in strategic investments	4,403	3,828
Total financial assets	7,025,698	6,406,074
Fair Value, Recurring Basis | Commercial paper
Financial Assets:
Marketable securities	19,636	41,564
Fair Value, Recurring Basis | Agency bonds
Financial Assets:
Marketable securities	1,768,712	1,666,683
Fair Value, Recurring Basis | Corporate and other debt securities
Financial Assets:
Marketable securities	712,223	663,159
Fair Value, Recurring Basis | U.S. government agency securities
Financial Assets:
Marketable securities	3,359,559	3,004,842
Fair Value, Recurring Basis | Treasury bills
Financial Assets:
Marketable securities	120,445	27,985
Fair Value, Recurring Basis | Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current assets	251
Certificates of deposit included in other assets, noncurrent		254
Fair Value, Recurring Basis | Money market funds
Financial Assets:
Cash equivalents	898,494	851,100
Fair Value, Recurring Basis | Treasury bills
Financial Assets:
Cash equivalents	113,107	100,629
Fair Value, Recurring Basis | Commercial paper
Financial Assets:
Cash equivalents	1,988
Fair Value, Recurring Basis | Corporate debt securities
Financial Assets:
Cash equivalents		2,715
Fair Value, Recurring Basis | Agency bonds
Financial Assets:
Cash equivalents		20,155
Fair Value, Recurring Basis | Level 1
Financial Assets:
Cash equivalents	898,494	851,100
Marketable securities	0	0
Publicly held equity securities included in strategic investments	26,880	23,160
Privately held debt securities included in strategic investments	0	0
Total financial assets	925,374	874,260
Fair Value, Recurring Basis | Level 1 | Commercial paper
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 1 | Agency bonds
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 1 | Corporate and other debt securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 1 | U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 1 | Treasury bills
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 1 | Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current assets	0
Certificates of deposit included in other assets, noncurrent		0
Fair Value, Recurring Basis | Level 1 | Money market funds
Financial Assets:
Cash equivalents	898,494	851,100
Fair Value, Recurring Basis | Level 1 | Treasury bills
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Level 1 | Commercial paper
Financial Assets:
Cash equivalents	0
Fair Value, Recurring Basis | Level 1 | Corporate debt securities
Financial Assets:
Cash equivalents		0
Fair Value, Recurring Basis | Level 1 | Agency bonds
Financial Assets:
Cash equivalents		0
Fair Value, Recurring Basis | Level 2
Financial Assets:
Cash equivalents	115,095	123,499
Marketable securities	5,980,575	5,404,233
Publicly held equity securities included in strategic investments	0	0
Privately held debt securities included in strategic investments	0	0
Total financial assets	6,095,921	5,527,986
Fair Value, Recurring Basis | Level 2 | Commercial paper
Financial Assets:
Marketable securities	19,636	41,564
Fair Value, Recurring Basis | Level 2 | Agency bonds
Financial Assets:
Marketable securities	1,768,712	1,666,683
Fair Value, Recurring Basis | Level 2 | Corporate and other debt securities
Financial Assets:
Marketable securities	712,223	663,159
Fair Value, Recurring Basis | Level 2 | U.S. government agency securities
Financial Assets:
Marketable securities	3,359,559	3,004,842
Fair Value, Recurring Basis | Level 2 | Treasury bills
Financial Assets:
Marketable securities	120,445	27,985
Fair Value, Recurring Basis | Level 2 | Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current assets	251
Certificates of deposit included in other assets, noncurrent		254
Fair Value, Recurring Basis | Level 2 | Money market funds
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Level 2 | Treasury bills
Financial Assets:
Cash equivalents	113,107	100,629
Fair Value, Recurring Basis | Level 2 | Commercial paper
Financial Assets:
Cash equivalents	1,988
Fair Value, Recurring Basis | Level 2 | Corporate debt securities
Financial Assets:
Cash equivalents		2,715
Fair Value, Recurring Basis | Level 2 | Agency bonds
Financial Assets:
Cash equivalents		20,155
Fair Value, Recurring Basis | 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	4,403	3,828
Total financial assets	4,403	3,828
Fair Value, Recurring Basis | Level 3 | Commercial paper
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 3 | Agency bonds
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 3 | Corporate and other debt securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 3 | U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 3 | Treasury bills
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis | Level 3 | Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current assets	0
Certificates of deposit included in other assets, noncurrent		0
Fair Value, Recurring Basis | Level 3 | Money market funds
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Level 3 | Treasury bills
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis | Level 3 | Commercial paper
Financial Assets:
Cash equivalents	$ 0
Fair Value, Recurring Basis | Level 3 | Corporate debt securities
Financial Assets:
Cash equivalents		0
Fair Value, Recurring Basis | Level 3 | Agency bonds
Financial Assets:
Cash equivalents		$ 0