Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Jan. 31, 2024	Jan. 31, 2023
Short-term investments:
Total financial assets	$ 1,724,904	$ 1,649,789
Level 1
Short-term investments:
Total financial assets	1,724,904	1,649,789
Level 2
Short-term investments:
Total financial assets	0	0
Level 3
Short-term investments:
Total financial assets	0	0
U.S. government treasury securities
Short-term investments:
U.S. government treasury securities	1,212,448	1,380,804
U.S. government treasury securities | Level 1
Short-term investments:
U.S. government treasury securities	1,212,448	1,380,804
U.S. government treasury securities | Level 2
Short-term investments:
U.S. government treasury securities	0	0
U.S. government treasury securities | Level 3
Short-term investments:
U.S. government treasury securities	0	0
Money market funds
Cash and cash equivalents:
Money market funds	512,456	268,985
Money market funds | Level 1
Cash and cash equivalents:
Money market funds	512,456	268,985
Money market funds | Level 2
Cash and cash equivalents:
Money market funds	0	0
Money market funds | Level 3
Cash and cash equivalents:
Money market funds	$ 0	$ 0