Equity Incentive Plans - Summary of Restricted Stock Unit Activity Under 2015 Plan (Details) - Restricted Stock Units	6 Months Ended
	Jul. 31, 2016 $ / shares shares
Number of Restricted Stock Units Outstanding
Number of Restricted Stock Units Outstanding, Unvested, Beginning balance (in shares) | shares	53,000
Number of Restricted Stock Units Outstanding, Granted (in shares) | shares	5,513,900
Number of Restricted Stock Units Outstanding, Vested (in shares) | shares	(264,648)
Number of Restricted Stock Units Outstanding, Forfeited (in shares) | shares	(134,734)
Number of Restricted Stock Units Outstanding, Unvested, Ending balance (in shares) | shares	5,167,518
Weighted-Average Grant Date Fair Value
Weighted-Average Grant Date Fair Value, Beginning balance (in dollars per share) | $ / shares	$ 16.98
Weighted-Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	13.46
Weighted-Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	14.38
Weighted-Average Grant Date Fair Value, Forfeited (in dollars per share) | $ / shares	14.51
Weighted-Average Grant Date Fair Value, Ending balance (in dollars per share) | $ / shares	$ 13.42