Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation and Other Employee Benefits - Additional Information (Details)

v3.20.4
Stock-Based Compensation and Other Employee Benefits - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 2 Months Ended 12 Months Ended
May 31, 2020
Nov. 30, 2019
Sep. 30, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2011
Dec. 31, 2017
Dec. 31, 2010
May 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Stock options outstanding (in shares)       2,916,000 3,505,000 3,305,000   3,834,000    
Granted (in shares)       406,000 1,330,000 518,000        
Exercise of stock options, net (in shares)       946,000 916,000 909,000        
Withholding tax on compensation from exercise of stock options   $ 2,292                
401(k) plan                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Employer matching contribution percent       100.00%            
Employer matching percent       6.00%            
Group Personal Pension Plan | UNITED KINGDOM                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Employer matching contribution percent       100.00%            
Employer matching percent       6.00%            
Registered Retirement Savings Plan | Canada                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Employer matching contribution percent       100.00%            
Employer matching percent       6.00%            
Chief Executive Officer                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Reimbursement due         $ 2,292          
Stock Options                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Ratable vesting percentage       33.33%            
Non-vested stock options unrecognized compensation expense       $ 12,103            
Non-vested stock options unrecognized compensation expense, weighted-average period of recognition       2 years 4 months 24 days            
Stock Options | Maximum                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options vesting period             5 years      
Stock Options | Minimum                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options vesting period       3 years            
Stock Options | 2019 Stock Option Grants                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Exercise term upon termination         90 days          
Class A Common Stock                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Common stock, par value (in usd per share)       $ 0.0001 $ 0.0001          
Class A Common Stock | Chief Executive Officer                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Exercise of stock options, net (in shares)     600,000              
2000 Stock Incentive Plan                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Shares reserved for future issuance (in shares)                 28,500,000  
Common stock, par value (in usd per share)                 $ 0.0001  
Stock options outstanding (in shares)       0            
2000 Stock Incentive Plan | Stock Options                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Shares available for grant (in shares)       4,790,000            
2000 Stock Incentive Plan | Class A Common Stock                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Shares reserved for future issuance (in shares) 5,000,000                  
Shares available for grant (in shares)       210,000            
2010 Stock Incentive Plan | Stock Options                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Shares available for grant (in shares)       0            
Options vesting period       10 years            
2010 Stock Incentive Plan | Stock Options | 2019 Stock Option Grants                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options vesting period         3 years          
Granted (in shares)         1,000,000          
Expiration period         10 years          
2010 Stock Incentive Plan | Class A Common Stock                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Shares reserved for future issuance (in shares)                   10,000,000
Shares available for grant (in shares)       5,461,000            
2017 Employee Stock Purchase Plan | Stock Options                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Number of allocated shares (up to) (in shares) 350             200    
Discount from fair value of stock (percent) 5.00%                  
Stock issued during period (in shares)       49,000 49,000          
Shares withheld for future purchases       99,000 62,000          
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Interval Term 6 months