Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 196,956	$ 131,364	$ 500,117	$ 290,102
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	152,134	105,615	385,464	229,892
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 44,822	$ 25,749	$ 114,653	$ 60,210