Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Narrative (Details)

v3.19.2
Stock-Based Compensation - Narrative (Details) - shares
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Performance stock units | 2018 Performance Stock Units          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Equity instruments other options, outstanding (in shares)         147,741
Equity instruments other than options, vested (in shares)     98,492    
Award vesting rights, percentage     100.00%    
Performance stock units | 2017 Performance Stock Units          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Equity instruments other options, outstanding (in shares)         140,493
Equity instruments other than options, vested (in shares)   116,168      
Shares issued (in shares)       25,726  
Award vesting rights, percentage       22.10%  
Performance stock units | 2007 Stock Incentive Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Equity instruments other than options, granted (in shares) 0 168,500 0 168,500  
Restricted stock | 2007 Stock Incentive Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Equity instruments other than options, vested (in shares)     98,492