v3.19.3.a.u2
Net Loss per Share - Additional Information (Details)
$ / shares in Units, $ in Thousands, shares in Millions
1 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2019
USD ($)
shares
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Earnings Per Share [Line Items]        
Net proceeds from initial public offering   $ 0 $ 0 $ 2,657,797
IPO | Class A Common Stock        
Earnings Per Share [Line Items]        
Common stock, shares issued and sold | shares 160.3 160.3    
Initial public offering price per share | $ / shares $ 17.00      
Net proceeds from initial public offering $ 2,600,000      
Underwriting discounts and commissions 68,100      
Other stock offering expenses $ 14,700      
Convertible Preferred Stock Other Than Series FP Preferred Stock | IPO | Class B Common Stock        
Earnings Per Share [Line Items]        
Conversion of convertible preferred stock into common stock | shares 246.8      
Series FP Preferred Stock | IPO | Class C Common Stock        
Earnings Per Share [Line Items]        
Conversion of convertible preferred stock into common stock | shares 215.9      
Conversion ratio   1    
Series D, E, and F Preferred Stock | IPO | Class B Common Stock        
Earnings Per Share [Line Items]        
Conversion ratio   1    
Series A, A-1, B, and C Preferred Stock | IPO | Class B Common Stock        
Earnings Per Share [Line Items]        
Conversion ratio   1