Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Narrative) (Details)

v3.10.0.1
Stock-Based Compensation (Narrative) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]        
Stock-based compensation expense $ 7,929 $ 3,873 $ 13,165 $ 6,599
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Dividend rate used     0.00%  
Weighted average GDFV of unvested shares (in dollars per share) $ 46.75   $ 46.75  
Aggregate fair value of all restricted shares     $ 2,200  
Series A common stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options to purchase shares granted (in shares)     5  
Shares reserved for issuance upon exercise 1,700   1,700  
Series B common stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options to purchase shares granted (in shares)     143  
Shares reserved for issuance upon exercise 1,200   1,200  
Options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to unvested options $ 14,000   $ 14,000  
Weighted average period for compensation cost to be recognized     1 year 9 months 12 days  
RSAs        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to unvested restricted shares $ 19,000   $ 19,000  
Weighted average period for compensation cost to be recognized     2 years  
Unvested restricted stock (in shares) 1,300   1,300  
RSUs        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unvested restricted stock (in shares) 32   32  
Directors | Series B common stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options to purchase shares granted (in shares)     5  
Granted options, weighted average GDFV (in dollars per share)     $ 13.36  
CEO | Series B common stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options to purchase shares granted (in shares)     143  
Granted options, weighted average GDFV (in dollars per share)     $ 16.55