Fair Value Measurement (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Jan. 31, 2023
Financial assets:
Total marketable securities	$ 814,097	$ 357,716
Commercial paper
Financial assets:
Total marketable securities	23,853	62,470
Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	602,777	234,540
Corporate bonds
Financial assets:
Total marketable securities	5,611	46,486
Municipal bonds
Financial assets:
Total marketable securities	998	6,308
Agency bonds
Financial assets:
Total marketable securities	180,858	7,912
Recurring
Financial assets:
Total cash equivalents	468,683	329,769
Total marketable securities	814,097	357,716
Total	1,282,780	687,485
Recurring | Money market
Financial assets:
Total cash equivalents	468,683	319,801
Recurring | Treasury bills
Financial assets:
Total cash equivalents		9,968
Recurring | Commercial paper
Financial assets:
Total marketable securities	23,853	62,470
Recurring | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	602,777	234,540
Recurring | Corporate bonds
Financial assets:
Total marketable securities	5,611	46,486
Recurring | Municipal bonds
Financial assets:
Total marketable securities	998	6,308
Recurring | Agency bonds
Financial assets:
Total marketable securities	180,858	7,912
Recurring | Level 1
Financial assets:
Total cash equivalents	468,683	329,769
Total marketable securities	783,635	242,452
Total	1,252,318	572,221
Recurring | Level 1 | Money market
Financial assets:
Total cash equivalents	468,683	319,801
Recurring | Level 1 | Treasury bills
Financial assets:
Total cash equivalents		9,968
Recurring | Level 1 | Commercial paper
Financial assets:
Total marketable securities	0	0
Recurring | Level 1 | Treasury bills and U.S. government securities
Financial assets:
Total marketable securities	602,777	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	180,858	7,912
Recurring | Level 2
Financial assets:
Total cash equivalents	0	0
Total marketable securities	30,462	115,264
Total	30,462	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
Recurring | Level 2 | Commercial paper
Financial assets:
Total marketable securities	23,853	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	5,611	46,486
Recurring | Level 2 | Municipal bonds
Financial assets:
Total marketable securities	998	6,308
Recurring | Level 2 | Agency bonds
Financial assets:
Total marketable securities	0	0
Recurring | Level 3
Financial assets:
Total	$ 0	$ 0