Equity Incentive Plans - Summary of Activity Under the Equity Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2016	Jan. 31, 2016
Options Outstanding, Number of Shares
Options Outstanding, Number of Shares, Beginning balance		68,879,087
Options Outstanding, Number of Shares, Options granted		1,979,000
Options Outstanding, Number of Shares, Options exercised		(4,258,667)
Options Outstanding, Number of Shares, Options forfeited/cancelled		(1,492,727)
Options Outstanding, Number of Shares, Ending balance	65,106,693	65,106,693	68,879,087
Options Outstanding, Number of Shares, Vested and exercisable	26,456,291	26,456,291
Options Outstanding, Weighted Average Exercise Price
Weighted Average Exercise Price, Beginning balance (in dollars per share)		$ 6.43
Weighted Average Exercise Price, Options granted (in dollars per share)		12.70
Weighted Average Exercise Price, Options exercised (in dollars per share)		1.57
Weighted Average Exercise Price, Options forfeited/cancelled (in dollars per share)		11.09
Weighted Average Exercise Price, Ending balance (in dollars per share)	$ 6.83	6.83	$ 6.43
Weighted Average Exercise Price, Vested and exercisable (in dollars per share)	$ 3.16	$ 3.16
Weighted Average Remaining Contractual Life (Years)	7 years 6 months		7 years 11 months
Weighted Average Remaining Contractual Life (Years), Vested and exercisable	6 years 6 months
Aggregate Intrinsic Value	$ 432,684	$ 432,684	$ 505,131
Aggregate Intrinsic Value, Vested and exercisable	$ 254,711	$ 254,711