v3.10.0.1
Net Loss per Share - Additional Information (Details)
$ / shares in Units, $ in Thousands, shares in Millions
1 Months Ended 12 Months Ended
Oct. 26, 2016
Mar. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2018
USD ($)
shares
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Earnings Per Share [Line Items]          
Net proceeds from initial public offering     $ 0 $ 2,657,797 $ 0
Class A Common Stock          
Earnings Per Share [Line Items]          
Conversion ratio 1.00        
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