Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation - Summary of Restricted Stock Award Activity for Employees and Non-Employee Directors (Details)

v3.10.0.1
Share-Based Compensation - Summary of Restricted Stock Award Activity for Employees and Non-Employee Directors (Details) - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Granted    
Forfeited (1,659)    
Restricted Stock [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Beginning Balance 97,098    
Granted 46,119    
Vested (43,931)    
Forfeited (8,105)    
Ending Balance 91,181 97,098  
Weighted Average Grant Date Fair Value Per Share, Beginning Balance $ 79.58    
Weighted Average Grant Date Fair Value Per, Granted 137.78 $ 90.16 $ 63.94
Weighted Average Grant Date Fair Value Per , Vested 79.86    
Weighted Average Grant Date Fair Value Per Share, Forfeited 100.09    
Weighted Average Grant Date Fair Value Per Share, Ending Balance $ 107.06 $ 79.58