Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Stock Option Plan and Restricted Stock Activity (Details)

v3.10.0.1
Stockholders' Equity - Stock Option Plan and Restricted Stock Activity (Details)
9 Months Ended
Sep. 30, 2018
$ / shares
shares
Stock Options  
Stock Options  
Balance at beginning of period (shares) | shares 1,876,332
Granted (shares) | shares 224,312
Options exercised/RSUs vested (shares) | shares (318,653)
Forfeited (shares) | shares (12,228)
Balance at end of period (shares) | shares 1,769,763
Weighted- Average Exercise Price  
Balance at beginning of period (USD per share) | $ / shares $ 53.17
Granted (USD per share) | $ / shares 161.83
Options exercised/RSUs vested (USD per share) | $ / shares 58.64
Forfeited (USD per share) | $ / shares 104.54
Balance at end of period (USD per share) | $ / shares $ 65.60
Restricted Stock Awards  
Restricted Stock Awards  
Nonvested at beginning of period (shares) | shares 133,294
Granted (shares) | shares 62,033
Exercised (shares) | shares (60,135)
Forfeited (shares) | shares (1,165)
Nonvested at end of period (shares) | shares 134,027
Weighted- Average Grant Date Fair Value  
Nonvested at beginning of period (USD per share) | $ / shares $ 91.60
Granted (USD per share) | $ / shares 169.91
Options exercised/RSUs vested (USD per share) | $ / shares 83.95
Forfeited (USD per share) | $ / shares 125.16
Nonvested at end of period (USD per share) | $ / shares $ 130.99