Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Summary of Restricted Stock Activity (Details)

v3.19.3.a.u2
Stockholders' Equity - Summary of Restricted Stock Activity (Details) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Time based restricted stock units      
Class Of Stock [Line Items]      
Unvested restricted stock units/ awards outstanding, Beginning balance 58,589 42,028  
Granted 87,902 31,877 42,028
Vested (24,680) (13,742)  
Forfeited/canceled (12,835) (1,574)  
Unvested restricted stock units/ awards outstanding, Ending balance 108,976 58,589 42,028
Performance and time based restricted stock units      
Class Of Stock [Line Items]      
Unvested restricted stock units/ awards outstanding, Beginning balance 8,739 13,109  
Granted     13,109
Vested (4,366) (4,370)  
Forfeited/canceled (1,239)    
Unvested restricted stock units/ awards outstanding, Ending balance 3,134 8,739 13,109
Restricted stock units      
Class Of Stock [Line Items]      
Unvested restricted stock units/ awards outstanding, Beginning balance 67,328 55,137  
Granted 87,902 31,877 55,137
Vested (29,046) (18,112)  
Forfeited/canceled (14,074) (1,574)  
Unvested restricted stock units/ awards outstanding, Ending balance 112,110 67,328 55,137
Unvested and expected to vest restricted stock units/awards outstanding 103,087 62,504 48,589
Weighted-average grant date fair value per share, Unvested restricted stock units/ awards outstanding, Beginning balance $ 115.16 $ 90.05  
Weighted-average grant date fair value per share, Granted 75.56 143.50 $ 90.05
Weighted-average grant date fair value per share, Vested 123.53 89.35  
Weighted-average grant date fair value per share, Forfeited/canceled 102.89 106.55  
Weighted-average grant date fair value per share, Unvested restricted stock units/ awards outstanding, Ending balance 83.48 115.16 90.05
Weighted-average grant date fair value per share, Unvested and expected to vest restricted stock units/awards outstanding $ 83.22 $ 115.98 $ 89.95
Time based restricted stock awards      
Class Of Stock [Line Items]      
Unvested restricted stock units/ awards outstanding, Beginning balance 36,937 20,789  
Granted 54,853 22,645 20,789
Vested (13,627) (6,497)  
Forfeited/canceled (7,093)    
Unvested restricted stock units/ awards outstanding, Ending balance 71,070 36,937 20,789
Performance and time based restricted stock awards      
Class Of Stock [Line Items]      
Unvested restricted stock units/ awards outstanding, Beginning balance 47,821 20,785  
Granted 40,166 33,964 20,785
Vested (15,732) (6,928)  
Forfeited/canceled (9,627)    
Unvested restricted stock units/ awards outstanding, Ending balance 62,628 47,821 20,785
Restricted stock awards      
Class Of Stock [Line Items]      
Unvested restricted stock units/ awards outstanding, Beginning balance 84,758 41,574  
Granted 95,019 56,609 41,574
Vested (29,359) (13,425)  
Forfeited/canceled (16,720)    
Unvested restricted stock units/ awards outstanding, Ending balance 133,698 84,758 41,574
Unvested and expected to vest restricted stock units/awards outstanding 79,473 65,773 34,051
Weighted-average grant date fair value per share, Unvested restricted stock units/ awards outstanding, Beginning balance $ 115.80 $ 91.52  
Weighted-average grant date fair value per share, Granted 86.10 130.89 $ 91.52
Weighted-average grant date fair value per share, Vested 115.37 91.52  
Weighted-average grant date fair value per share, Forfeited/canceled 109.11    
Weighted-average grant date fair value per share, Unvested restricted stock units/ awards outstanding, Ending balance 95.74 115.80 91.52
Weighted-average grant date fair value per share, Unvested and expected to vest restricted stock units/awards outstanding $ 90.31 $ 115.85 $ 91.52