XML 41 R30.htm IDEA: XBRL DOCUMENT
v3.20.2

Fair Value Measurements - Additional Information (Details) - USD ($) | Jul. 31, 2020 | Jan. 31, 2019
--- | --- | ---
Fair Value Disclosures [Abstract] |  |
Fair value level asset and liability | $ 0 | $ 0

X
- References No definition available. + Details
Name: | us-gaap_FairValueDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of asset after deduction of liability. + References No definition available. + Details
Name: | us-gaap_FairValueNetAssetLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant