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Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Jan. 31, 2019 | Jan. 31, 2018 | Jan. 31, 2017
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] |  |  |
Rental expense | $ 0.8 | $ 0.7 | $ 0.5

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- References No definition available. + Details
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- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717 + Details
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