Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
Stockholders' Equity - Stock Option Plan and Restricted Stock Activity (Details)
3 Months Ended
Mar. 31, 2019
$ / shares
shares
Stock Options  
Stock Options  
Balance at beginning of period (shares) | shares 1,736,304
Granted (shares) | shares 283,387
Options exercised (shares) | shares (92,036)
Balance at end of period (shares) | shares 1,927,655
Weighted- Average Exercise Price  
Balance at beginning of period (USD per share) | $ / shares $ 66.71
Granted (USD per share) | $ / shares 118.04
Options exercised (USD per share) | $ / shares 21.26
Balance at end of period (USD per share) | $ / shares $ 76.43
Restricted Stock Awards  
Restricted Stock Awards  
Nonvested at beginning of period (shares) | shares 132,273
Granted (shares) | shares 60,857
RSUs vested (shares) | shares (66,078)
Nonvested at end of period (shares) | shares 127,052
Weighted- Average Grant Date Fair Value  
Nonvested at beginning of period (USD per share) | $ / shares $ 130.63
Granted (USD per share) | $ / shares 115.83
RSUs vested (USD per share) | $ / shares 106.42
Nonvested at end of period (USD per share) | $ / shares $ 136.13