Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Restricted Stock) (Details)

v3.10.0.1
Stock-Based Compensation (Restricted Stock) (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2018
Mar. 31, 2018
Jun. 30, 2018
Unvested restricted stock units and awards      
Number of Shares      
Balance at the beginning of the period (in shares) 2,161,347 1,766,639 1,766,639
Granted (in shares)   925,641  
Vested (in shares) (253,279) (503,668)  
Forfeited (in shares) (27,324) (27,265)  
Balance at the end of the period (in shares) 1,880,744 2,161,347 1,880,744
Weighted-Average Grant Date Fair Value per Share      
Balance at the beginning of the period (in dollars per share) $ 41.59 $ 32.48 $ 32.48
Granted (in dollars per share)   55.21  
Vested (in dollars per share) 31.13 34.05  
Forfeited (in dollars per share) 39.78 30.79  
Balance at the end of the period (in dollars per share) $ 43.36 $ 41.59 $ 43.36
Additional disclosures      
Unrecognized compensation expense related to shares $ 73,482   $ 73,482
Unrecognized compensation expense weighted-average recognition period     2 years 2 months 12 days
Stock options      
Additional disclosures      
Unrecognized compensation expense weighted-average recognition period     1 year 4 months 24 days
Performance-based restricted stock unit awards      
Number of Shares      
Vested (in shares)   (26,000)