Stockholders’ Equity and Equity Incentive Plan - Summary of Restricted Stock Units Activity Under Equity Incentive Plan (Details) - RSUs	3 Months Ended
	Apr. 30, 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	419,354
Vested (in shares) | shares	(37,518)
Cancelled/forfeited (in units) | shares	(33,653)
Ending balance (in units) | shares	2,312,851
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	119.62
Vested (in dollars per unit) | $ / shares	80.36
Cancelled/forfeited (in dollars per unit) | $ / shares	80.78
Ending balance (in dollars per unit) | $ / shares	$ 86.42