Property and Equipment, Net - Components of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Jul. 31, 2017	Jan. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 64,180	$ 58,778
Less accumulated depreciation	(10,652)	(8,871)
Total property and equipment, net	53,528	49,907
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	19,730	14,731
Equipment and computers [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,453	7,197
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,379	7,322
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,041	2,615
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 553	$ 2,889