Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Retirement Savings Plan [Member]
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Defined contribution plan, cost recognized	$ 0.4	$ 0.5

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration