Segment Information - Schedule of Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Jan. 31, 2018	Jan. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net	$ 89,142	$ 81,695
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net	85,430	78,692
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net	$ 3,712	$ 3,003