Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 973,971	$ 700,969	$ 518,504
Long-Lived Assets	278,126	75,832
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	802,480	581,011	428,551
Long-Lived Assets	182,288	60,625
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	171,491	119,958	$ 89,953
Long-Lived Assets	$ 95,838	$ 15,207