Segment Information - Revenue by Geographic Area by Customer Location (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 125,904	$ 125,105	$ 86,012
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	91,324	87,519	60,300
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	19,256	18,207	13,712
Rest of the World
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 15,324	$ 19,379	$ 12,000