Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Segment Reporting Information [Line Items]
Aggregate amortization expense	$ 1.8	$ 1.5	$ 1.5
Klein Associates Inc.
Segment Reporting Information [Line Items]
Goodwill, impairment		$ 1.5

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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