Nature of Business and Basis of Presentation - Additional Information (Detail) $ in Millions	3 Months Ended
Apr. 30, 2019 USD ($)
Restructuring Plan [Member] \| Minimum [Member]
Significant Accounting Policies [Line Items]
Annualized cost savings	$ 6

The quantified amount of the future effect on earnings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4)
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

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