Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Restricted Stock Activity (Details)

v3.10.0.1
Stockholders' Equity - Restricted Stock Activity (Details) - Restricted Stock
12 Months Ended
Dec. 31, 2018
$ / shares
shares
Shares [Rollforward]  
Outstanding at beginning of period (shares) | shares 133,294
Granted (shares) | shares 62,133
Vested (shares) | shares (61,989)
Forfeited (shares) | shares (1,165)
Outstanding at end of period (shares) | shares 132,273
Weighted-Average Grant Date Fair Value [Roll Forward]  
Outstanding at beginning of period (USD per share) | $ / shares $ 91.60
Granted (USD per share) | $ / shares 169.92
Vested (USD per share) | $ / shares 86.19
Forfeited (USD per share) | $ / shares 125.16
Outstanding at end of period (USD per share) | $ / shares $ 130.63