Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Oct. 31, 2024	Jan. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 830,251	$ 818,246
Gross Unrealized Gains	94	29
Gross Unrealized Losses	(537)	(130)
Estimated Fair Value	829,808	818,145
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	41,864
Gross Unrealized Gains	18
Gross Unrealized Losses	0
Estimated Fair Value	41,882
Treasury bills and U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	674,654	641,263
Gross Unrealized Gains	0	29
Gross Unrealized Losses	(526)	(100)
Estimated Fair Value	674,128	641,192
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	108,606	1,993
Gross Unrealized Gains	76	0
Gross Unrealized Losses	0	(2)
Estimated Fair Value	108,682	1,991
Yankee bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,677
Gross Unrealized Gains	0
Gross Unrealized Losses	(11)
Estimated Fair Value	4,666
Agency bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	450	174,990
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(28)
Estimated Fair Value	$ 450	$ 174,962