Fair Value Measurements (Details) - USD ($) $ in Thousands	Jan. 31, 2022	Jan. 31, 2021
Short-term investments:
Short-term investments	$ 374	$ 364
Total assets measured and recorded at fair value	1,642,017	40,882
Level 1
Short-term investments:
Total assets measured and recorded at fair value	1,641,642	40,518
Level 2
Short-term investments:
Total assets measured and recorded at fair value	375	364
Level 3
Short-term investments:
Total assets measured and recorded at fair value	0	0
Certificates of deposit
Short-term investments:
Short-term investments	375	364
Certificates of deposit | Level 1
Short-term investments:
Short-term investments	0	0
Certificates of deposit | Level 2
Short-term investments:
Short-term investments	375	364
Certificates of deposit | Level 3
Short-term investments:
Short-term investments	0	0
Money market funds
Cash equivalents:
Money market funds	1,641,642	40,518
Money market funds | Level 1
Cash equivalents:
Money market funds	1,641,642	40,518
Money market funds | Level 2
Cash equivalents:
Money market funds	0	0
Money market funds | Level 3
Cash equivalents:
Money market funds	$ 0	$ 0