Stockholders’ Equity and Equity Incentive Plans - Summary of Restricted Stock Units Activity Under Equity Incentive Plan (Details) - RSUs	6 Months Ended
	Jul. 31, 2020 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in units) | shares	1,964,668
Granted (in units) | shares	2,617,599
Vested (in shares) | shares	(166,366)
Cancelled/forfeited (in units) | shares	(45,290)
Ending balance (in units) | shares	4,370,611
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in dollars per unit) | $ / shares	$ 79.11
Granted (in dollars per unit) | $ / shares	202.30
Vested (in dollars per unit) | $ / shares	88.53
Cancelled/forfeited (in dollars per unit) | $ / shares	98.34
Ending balance (in dollars per unit) | $ / shares	$ 152.33