v3.20.4
Balance Sheet Components (Details) - USD ($)
 12 Months Ended
Jan. 31, 2021
Jan. 31, 2020
Jan. 31, 2019
Property, Plant and Equipment [Line Items]      
Depreciation and amortization expense $ 38,700,000 $ 23,000,000.0 $ 14,800,000
Capitalized computer software impairments 0 0 0
Capitalized computer software additions 14,000,000.0 8,100,000 6,800,000
Capitalized computer software amortization 7,900,000 6,200,000 5,200,000
Capitalized computer software net 19,500,000 13,400,000  
Amortization 1,400,000 500,000 $ 600,000
Other Current Liabilities      
Property, Plant and Equipment [Line Items]      
Deferred payroll taxes owed 5,100,000    
Other Noncurrent Liabilities      
Property, Plant and Equipment [Line Items]      
Deferred payroll taxes owed $ 5,100,000    
Developed technology      
Property, Plant and Equipment [Line Items]      
Useful life 5 years    
Customer relationships      
Property, Plant and Equipment [Line Items]      
Useful life 5 years    
Other acquired intangible assets      
Property, Plant and Equipment [Line Items]      
Useful life 1 year    
Data center and other computer equipment      
Property, Plant and Equipment [Line Items]      
Equipment additions $ 30,000,000.0 $ 44,900,000