Fair Value Measurement (Details) - USD ($)	Jan. 31, 2023	Jan. 31, 2022
Financial Assets:
Total marketable securities	$ 357,716,000	$ 115,940,000
Commercial paper
Financial Assets:
Total marketable securities	62,470,000	15,343,000
Treasury bills
Financial Assets:
Total marketable securities	234,540,000
Corporate bonds
Financial Assets:
Total marketable securities	46,486,000	91,432,000
Municipal bonds
Financial Assets:
Total marketable securities	6,308,000	9,165,000
Agency bonds
Financial Assets:
Total marketable securities	7,912,000
Recurring
Financial Assets:
Total cash equivalents	329,769,000	1,056,555,000
Total marketable securities	357,716,000	115,940,000
Total	687,485,000	1,172,495,000
Recurring | Commercial paper
Financial Assets:
Total marketable securities	62,470,000	15,343,000
Recurring | Treasury bills
Financial Assets:
Total marketable securities	234,540,000
Recurring | Corporate bonds
Financial Assets:
Total marketable securities	46,486,000	91,432,000
Recurring | Municipal bonds
Financial Assets:
Total marketable securities	6,308,000	9,165,000
Recurring | Agency bonds
Financial Assets:
Total marketable securities	7,912,000
Recurring | Money market funds
Financial Assets:
Total cash equivalents	319,801,000	1,056,555,000
Recurring | Treasury bills
Financial Assets:
Total cash equivalents	9,968,000
Recurring | Level 1
Financial Assets:
Total cash equivalents	329,769,000	1,056,555,000
Total marketable securities	242,452,000	0
Total	572,221,000	1,056,555,000
Recurring | Level 1 | Commercial paper
Financial Assets:
Total marketable securities	0	0
Recurring | Level 1 | Treasury bills
Financial Assets:
Total marketable securities	234,540,000
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	7,912,000
Recurring | Level 1 | Money market funds
Financial Assets:
Total cash equivalents	319,801,000	1,056,555,000
Recurring | Level 1 | Treasury bills
Financial Assets:
Total cash equivalents	9,968,000
Recurring | Level 2
Financial Assets:
Total cash equivalents	0	0
Total marketable securities	115,264,000	115,940,000
Total	115,264,000	115,940,000
Recurring | Level 2 | Commercial paper
Financial Assets:
Total marketable securities	62,470,000	15,343,000
Recurring | Level 2 | Treasury bills
Financial Assets:
Total marketable securities	0
Recurring | Level 2 | Corporate bonds
Financial Assets:
Total marketable securities	46,486,000	91,432,000
Recurring | Level 2 | Municipal bonds
Financial Assets:
Total marketable securities	6,308,000	9,165,000
Recurring | Level 2 | Agency bonds
Financial Assets:
Total marketable securities	0
Recurring | Level 2 | Money market funds
Financial Assets:
Total cash equivalents	0	0
Recurring | Level 2 | Treasury bills
Financial Assets:
Total cash equivalents	0
Recurring | Level 3
Financial Assets:
Total cash equivalents	0	0
Total marketable securities	0	0
Total	0	0
Recurring | Level 3 | Commercial paper
Financial Assets:
Total marketable securities	0	0
Recurring | Level 3 | Treasury bills
Financial Assets:
Total marketable securities	0
Recurring | Level 3 | Corporate bonds
Financial Assets:
Total marketable securities	0	0
Recurring | Level 3 | Municipal bonds
Financial Assets:
Total marketable securities	0	0
Recurring | Level 3 | Agency bonds
Financial Assets:
Total marketable securities	0
Recurring | Level 3 | Money market funds
Financial Assets:
Total cash equivalents	0	$ 0
Recurring | Level 3 | Treasury bills
Financial Assets:
Total cash equivalents	$ 0