Severance and Restructuring Costs - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
Apr. 30, 2020	Apr. 30, 2019
Restructuring And Related Activities [Abstract]
Severance and restructuring costs	$ 486	$ 211

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration