Balance Sheet Components - Schedule of Other Long-Term Assets (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019
Property Plant And Equipment [Line Items]
Capitalized stock-based compensation expenses	$ 5.0	$ 0.8
Maximum
Property Plant And Equipment [Line Items]
Finite-lived intangible assets estimated useful lives	7 years
Minimum
Property Plant And Equipment [Line Items]
Finite-lived intangible assets estimated useful lives	2 years
On-premises software | Maximum
Property Plant And Equipment [Line Items]
Finite-lived intangible assets estimated useful lives	4 years
On-premises software | Minimum
Property Plant And Equipment [Line Items]
Finite-lived intangible assets estimated useful lives	3 years