v3.19.3.a.u2
The Company - Additional Information (Details)
$ / shares in Units, shares in Millions, $ in Millions
 12 Months Ended
Oct. 02, 2017
USD ($)
ClassesofStock
Vote
$ / shares
shares
Dec. 31, 2019
segment
Entity Wide Revenue Major Customer [Line Items]    
Conversion date   Feb. 01, 2008
Number of reportable segments operates | segment   2
Number of classes of authorized common stock | ClassesofStock 2  
Class A Common Stock    
Entity Wide Revenue Major Customer [Line Items]    
Number of votes per share | Vote 1  
Class B Common Stock    
Entity Wide Revenue Major Customer [Line Items]    
Number of votes per share | Vote 10  
Initial Public Offering | Class B Common Stock Warrants    
Entity Wide Revenue Major Customer [Line Items]    
Warrants conversion ratio 100.00%  
Initial Public Offering | Class A Common Stock    
Entity Wide Revenue Major Customer [Line Items]    
Initial public offering completed date Oct. 02, 2017  
Number of shares sold | shares 10.4  
Share sold price per share | $ / shares $ 14.00  
Net proceeds from shares sold | $ $ 134.8  
Underwriting discounts and commissions | $ 10.1  
Offering costs incurred | $ $ 3.1  
Initial Public Offering | Class B Common Stock    
Entity Wide Revenue Major Customer [Line Items]    
Convertible preferred stock, Shares converted | shares 80.8  
Stock conversion ratio 100.00%  
Over-Allotment Option | Class A Common Stock    
Entity Wide Revenue Major Customer [Line Items]    
Number of shares sold | shares 1.4