Revenue - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020	Jan. 31, 2021
Revenues [Abstract]
Deferred revenue	$ 297,900,000		$ 297,900,000		$ 238,000,000
Percent of revenue recognized from deferred revenue			30.00%	35.00%
Remaining performance obligation	353,400,000		$ 353,400,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unbilled receivables	6,900,000		$ 6,900,000		5,700,000
Percent of revenue recognized from deferred revenue			30.00%	35.00%
Deferred commissions	153,400,000		$ 153,400,000		118,600,000
Amortization of deferred commissions	13,300,000	$ 7,200,000	33,500,000	$ 20,500,000
Unbilled receivables	6,900,000		6,900,000		5,700,000
Deferred commissions	153,400,000		153,400,000		$ 118,600,000
Amortization of deferred commissions	13,300,000	7,200,000	33,500,000	20,500,000
Impairment loss	$ 0	$ 0	$ 0	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	61.00%		61.00%
Expected timing of satisfaction of remaining performance obligation	12 months		12 months