Property and Equipment, Net - Components of Property and Equipment, Net (Detail) - USD ($) $ in Thousands		Apr. 30, 2019	Jan. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 73,008	$ 71,230
Less accumulated depreciation		(17,742)	(16,264)
Total property and equipment, net	[1]	55,266	54,966
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		3,040	3,040
Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		20,984	20,984
Land improvements and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		20,917	20,911
Equipment and computers [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		9,217	7,945
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		11,385	11,230
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		7,124	6,790
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 341	$ 330

[1] We adopted ASU 2016-02, “Leases” (Topic 842) using the modified retrospective method as of February 1, 2019 and elected the transition option that allows us not to restate the comparative periods in our financial statements in the year of adoption.