Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Oct. 31, 2022	Jan. 31, 2022
Assets:
Cash equivalents, fair value	$ 91,598	$ 152,223
Short term investments, fair value	2,223,538	2,241,657
Total cash equivalents and short-term investments	2,315,136	2,393,880
U.S. treasury securities
Assets:
Short term investments, fair value	1,997,540	1,912,188
Corporate debt securities
Assets:
Short term investments, fair value	225,998	329,469
Money market funds
Assets:
Cash equivalents, fair value	91,598	152,223
Level 1
Assets:
Cash equivalents, fair value	91,598	152,223
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	91,598	152,223
Level 1 | U.S. treasury securities
Assets:
Short term investments, fair value	0	0
Level 1 | Corporate debt securities
Assets:
Short term investments, fair value	0	0
Level 1 | Money market funds
Assets:
Cash equivalents, fair value	91,598	152,223
Level 2
Assets:
Cash equivalents, fair value	0	0
Short term investments, fair value	2,223,538	2,241,657
Total cash equivalents and short-term investments	2,223,538	2,241,657
Level 2  | U.S. treasury securities
Assets:
Short term investments, fair value	1,997,540	1,912,188
Level 2  | Corporate debt securities
Assets:
Short term investments, fair value	225,998	329,469
Level 2  | Money market funds
Assets:
Cash equivalents, fair value	0	0
Level 3
Assets:
Cash equivalents, fair value	0	0
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	0	0
Level 3 | U.S. treasury securities
Assets:
Short term investments, fair value	0	0
Level 3 | Corporate debt securities
Assets:
Short term investments, fair value	0	0
Level 3 | Money market funds
Assets:
Cash equivalents, fair value	$ 0	$ 0