v3.20.1
Fair Value Measurements and Marketable Securities - Financial Assets and Liabilities (Details)
$ in Thousands
 12 Months Ended
Jun. 14, 2019
shares
Jan. 31, 2020
USD ($)
unit_Standard_item
Jan. 31, 2019
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Number Of probability adjusted milestone payments | unit_Standard_item   3  
Probability adjusted milestone payment amount   $ 200  
First milestone payment     $ 200
Contingent consideration written off   $ 500  
Class B Common Stock      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Shares issued upon conversion of warrants (in shares) | shares 336,386    
Shares issued (in shares) | shares 322,278    
IPO | Class B Common Stock      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Warrants Issued (in shares) | shares 336,386    
Warrants conversion ratio 1    
Measurement Input, Discount Rate | Minimum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Discount rate   0.03  
Measurement Input, Discount Rate | Maximum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Discount rate   0.0302  
Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   $ 245,319 70,073
Marketable securities   647,266 103,247
Total assets   892,585 173,320
Contingent consideration related to business combinations     474
Redeemable convertible preferred stock warrant liability     4,537
Total liabilities     5,011
Money Market Funds | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   205,379 42,132
Corporate debt securities | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   39,940 27,941
Marketable securities   495,022 91,796
US Treasury securities | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Marketable securities   84,431 11,451
Asset backed securities | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Marketable securities   67,813  
Fair Value, Inputs, Level 1 | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   205,379 42,132
Marketable securities   84,431 11,451
Total assets   289,810 53,583
Fair Value, Inputs, Level 1 | Money Market Funds | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   205,379 42,132
Fair Value, Inputs, Level 1 | US Treasury securities | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Marketable securities   84,431 11,451
Fair Value, Inputs, Level 2 | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   39,940 27,941
Marketable securities   562,835 91,796
Total assets   602,775 119,737
Fair Value, Inputs, Level 2 | Corporate debt securities | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Cash and cash equivalents   39,940 27,941
Marketable securities   495,022 91,796
Fair Value, Inputs, Level 2 | Asset backed securities | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Marketable securities   67,813  
Fair Value, Inputs, Level 3 | Fair Value, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Total assets   $ 0  
Contingent consideration related to business combinations     474
Redeemable convertible preferred stock warrant liability     4,537
Total liabilities     $ 5,011