XML 52 R41.htm IDEA: XBRL DOCUMENT v3.19.1
Restricted Stock Units - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Vested deferred restricted stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vested and remaining outstanding (in shares) 98,763 98,763  
Unvested units outstanding (in shares) 539,394   503,511
Unrecognized stock-based compensation expense $ 666    
Performance-based Restricted Stock Units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unvested units outstanding (in shares) 497,061    
Unrecognized stock-based compensation expense $ 637    
Time-based Restricted Stock Units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unvested units outstanding (in shares) 42,333    
Unrecognized stock-based compensation expense $ 29    
Weighted average period for amortization of unrecognized stock-based compensation 12 months 20 days    
Non-Employee Directors | Vested deferred restricted stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vested and remaining outstanding (in shares) 98,763    
Shares Withheld and Repurchased | Vested deferred restricted stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares withheld and repurchased to satisfy tax obligation (in shares) 877    
Statutory tax withholding requirements $ 1