Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jan. 31, 2026	Jan. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross Unrealized Gains	$ 814	$ 535
Gross Unrealized Losses	(94)	(407)
Total amortized cost	720,008	632,786
Total estimated fair value	720,728	632,914
Cash	354,100	464,700
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, amortized cost	248,251	183,885
Cash equivalents, estimated fair value	248,251	183,885
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	471,757	448,901
Gross Unrealized Gains	814	535
Gross Unrealized Losses	(94)	(407)
Estimated Fair Value	472,477	449,029
Level 2 | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	32,611	31,367
Gross Unrealized Gains	7	12
Gross Unrealized Losses	(6)	(8)
Estimated Fair Value	32,612	31,371
Level 2 | Corporate notes and bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	425,648	399,034
Gross Unrealized Gains	806	522
Gross Unrealized Losses	(77)	(378)
Estimated Fair Value	426,377	399,178
Level 2 | U.S. governmental securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	13,498	18,500
Gross Unrealized Gains	1	1
Gross Unrealized Losses	(11)	(21)
Estimated Fair Value	$ 13,488	$ 18,480