Basis of Presentation and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 159,624	$ 73,012	$ 401,584	$ 177,056
Product revenue
Disaggregation of Revenue [Line Items]
Revenue	148,473	69,213	375,506	169,797
Professional services and other revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 11,151	$ 3,799	$ 26,078	$ 7,259