Fair Value Measurement (Details) - USD ($) $ in Thousands	Jul. 31, 2023	Jan. 31, 2023
Financial assets:
Total marketable securities	$ 735,670	$ 357,716
Commercial paper
Financial assets:
Total marketable securities	61,740	62,470
Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	555,548	234,540
Corporate bonds
Financial assets:
Total marketable securities	10,770	46,486
Municipal bonds
Financial assets:
Total marketable securities	1,736	6,308
Agency bonds
Financial assets:
Total marketable securities	105,876	7,912
Recurring
Financial assets:
Total cash equivalents	592,940	329,769
Total marketable securities	735,670	357,716
Total	1,328,610	687,485
Recurring | Money market
Financial assets:
Total cash equivalents	528,156	319,801
Recurring | Treasury bills
Financial assets:
Total cash equivalents	39,807	9,968
Recurring | Commercial paper
Financial assets:
Total cash equivalents	24,977
Total marketable securities	61,740	62,470
Recurring | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	555,548	234,540
Recurring | Corporate bonds
Financial assets:
Total marketable securities	10,770	46,486
Recurring | Municipal bonds
Financial assets:
Total marketable securities	1,736	6,308
Recurring | Agency bonds
Financial assets:
Total marketable securities	105,876	7,912
Recurring | Level 1
Financial assets:
Total cash equivalents	567,963	329,769
Total marketable securities	661,424	242,452
Total	1,229,387	572,221
Recurring | Level 1 | Money market
Financial assets:
Total cash equivalents	528,156	319,801
Recurring | Level 1 | Treasury bills
Financial assets:
Total cash equivalents	39,807	9,968
Recurring | Level 1 | Commercial paper
Financial assets:
Total cash equivalents	0
Total marketable securities	0	0
Recurring | Level 1 | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	555,548	234,540
Recurring | Level 1 | Corporate bonds
Financial assets:
Total marketable securities	0	0
Recurring | Level 1 | Municipal bonds
Financial assets:
Total marketable securities	0	0
Recurring | Level 1 | Agency bonds
Financial assets:
Total marketable securities	105,876	7,912
Recurring | Level 2
Financial assets:
Total cash equivalents	24,977	0
Total marketable securities	74,246	115,264
Total	99,223	115,264
Recurring | Level 2 | Money market
Financial assets:
Total cash equivalents	0	0
Recurring | Level 2 | Treasury bills
Financial assets:
Total cash equivalents	0	0
Recurring | Level 2 | Commercial paper
Financial assets:
Total cash equivalents	24,977
Total marketable securities	61,740	62,470
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	10,770	46,486
Recurring | Level 2 | Municipal bonds
Financial assets:
Total marketable securities	1,736	6,308
Recurring | Level 2 | Agency bonds
Financial assets:
Total marketable securities	0	0
Recurring | Level 3
Financial assets:
Total	$ 0	$ 0