Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 182,631	$ 139,947
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	146,494	111,227
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 36,137	$ 28,720