Investments and Fair Value Measurements (Details) - USD ($) $ in Thousands	Jan. 31, 2023	Jan. 31, 2022
Estimate of Fair Value Measurement | Recurring basis
Assets:
Money market funds	$ 316,943	$ 1,056,296
Assets
Cash and cash equivalents	376,649	1,059,296
Investments, current	1,316,347	286,337
Investments, non-current	0	9,932
Total	1,692,996	1,355,565
Estimate of Fair Value Measurement | Level 1 | Recurring basis
Assets:
Money market funds	316,943	1,056,296
Estimate of Fair Value Measurement | Level 2 | Recurring basis
Assets:
Money market funds	0	0
Estimate of Fair Value Measurement | Level 3 | Recurring basis
Assets:
Money market funds	0	0
U.S. government and agency securities, corporate bonds and commercial paper	1,376,053	299,269
U.S. Government and Agency Securities | Estimate of Fair Value Measurement | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	1,180,861	8,024
U.S. Government and Agency Securities | Estimate of Fair Value Measurement | Level 1 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	0	0
U.S. Government and Agency Securities | Estimate of Fair Value Measurement | Level 2 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	1,180,861	8,024
U.S. Government and Agency Securities | Estimate of Fair Value Measurement | Level 3 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	0	0
Corporate Bonds | Estimate of Fair Value Measurement | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	53,833	131,015
Corporate Bonds | Estimate of Fair Value Measurement | Level 1 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	0	0
Corporate Bonds | Estimate of Fair Value Measurement | Level 2 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	53,833	131,015
Corporate Bonds | Estimate of Fair Value Measurement | Level 3 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	0	0
Commercial Paper | Estimate of Fair Value Measurement | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	141,359	160,230
Commercial Paper | Estimate of Fair Value Measurement | Level 1 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	0	0
Commercial Paper | Estimate of Fair Value Measurement | Level 2 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	141,359	160,230
Commercial Paper | Estimate of Fair Value Measurement | Level 3 | Recurring basis
Assets:
U.S. government and agency securities, corporate bonds and commercial paper	$ 0	$ 0