Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 163,214	$ 84,661	$ 303,161	$ 158,738
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	122,103	65,603	233,330	124,277
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 41,111	$ 19,058	$ 69,831	$ 34,461