Fair Value Measurement (Details) - USD ($) $ in Thousands	Jul. 31, 2025	Jan. 31, 2025
Financial assets:
Total marketable securities	$ 894,021	$ 844,435
Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	791,993	703,319
Corporate bonds
Financial assets:
Total marketable securities	87,055	94,025
Commercial paper
Financial assets:
Total marketable securities	14,973	42,391
Yankee bonds
Financial assets:
Total marketable securities		4,700
Recurring
Financial assets:
Total cash equivalents	183,542	311,942
Total marketable securities	894,021	844,435
Other investments carried at fair value	13,375	11,879
Total	1,090,938	1,168,256
Financial liabilities:
Contingent consideration	1,545
Total	1,545
Recurring | Money market funds
Financial assets:
Total cash equivalents	183,542	311,942
Recurring | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	791,993	703,319
Recurring | Corporate bonds
Financial assets:
Total marketable securities	87,055	94,025
Recurring | Commercial paper
Financial assets:
Total marketable securities	14,973	42,391
Recurring | Yankee bonds
Financial assets:
Total marketable securities		4,700
Recurring | Level 1
Financial assets:
Total cash equivalents	183,542	311,942
Total marketable securities	791,993	703,319
Other investments carried at fair value	0	0
Total	975,535	1,015,261
Financial liabilities:
Contingent consideration	0
Total	0
Recurring | Level 1 | Money market funds
Financial assets:
Total cash equivalents	183,542	311,942
Recurring | Level 1 | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	791,993	703,319
Recurring | Level 1 | Corporate bonds
Financial assets:
Total marketable securities	0	0
Recurring | Level 1 | Commercial paper
Financial assets:
Total marketable securities	0	0
Recurring | Level 1 | Yankee bonds
Financial assets:
Total marketable securities		0
Recurring | Level 2
Financial assets:
Total cash equivalents	0	0
Total marketable securities	102,028	141,116
Other investments carried at fair value	0	0
Total	102,028	141,116
Financial liabilities:
Contingent consideration	0
Total	0
Recurring | Level 2 | Money market funds
Financial assets:
Total cash equivalents	0	0
Recurring | Level 2 | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	0	0
Recurring | Level 2 | Corporate bonds
Financial assets:
Total marketable securities	87,055	94,025
Recurring | Level 2 | Commercial paper
Financial assets:
Total marketable securities	14,973	42,391
Recurring | Level 2 | Yankee bonds
Financial assets:
Total marketable securities		4,700
Recurring | Level 3
Financial assets:
Total cash equivalents	0	0
Total marketable securities	0	0
Other investments carried at fair value	13,375	11,879
Total	13,375	11,879
Financial liabilities:
Contingent consideration	1,545
Total	1,545
Recurring | Level 3 | Money market funds
Financial assets:
Total cash equivalents	0	0
Recurring | Level 3 | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	0	0
Recurring | Level 3 | Corporate bonds
Financial assets:
Total marketable securities	0	0
Recurring | Level 3 | Commercial paper
Financial assets:
Total marketable securities	$ 0	0
Recurring | Level 3 | Yankee bonds
Financial assets:
Total marketable securities		$ 0