Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jul. 31, 2021	Jan. 31, 2021	Jan. 31, 2020
Money Market Funds [Member]
Unrealized gains or losses	$ 0	$ 0	$ 0

Amount of unrealized gain (loss) on investment in marketable security.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Name:	us-gaap_MarketableSecuritiesUnrealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration