Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments - Employee Activity Non-vested Shares (Details)

v3.8.0.1
Share-Based Payments - Employee Activity Non-vested Shares (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 2,261 $ 1,962
Employee Non-vested Shares [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Grants, vesting period (in years) 3 years  
Outstanding and non-vested, beginning of period (in shares) 227  
Stock Issued During Period, Shares, Restricted Stock Award, Gross 122  
Shares Vested in Period (105)  
Shares Forfeited in Period (2)  
Outstanding and non-vested, end of period (in shares) 242  
Outstanding and non-vested, weighted-average grant date fair value, beginning of period $ 47  
Grants in Period, Weighted Average Grant Date Fair Value 58  
Vested in Period, Weighed-average grant date fair value 56  
Forfeited in period (in dollars per share) 52  
Outstanding and non-vested, weighted-average grant date fair value, end of period $ 52  
Outstanding and non-vested, aggregate grant date fair value $ 12,690  
Share-based compensation expense 1,399 1,246
Tax benefit related to share-based expense 360 459
Unrecognized share-based compensation, net of estimated forfeitures $ 11,747 $ 10,470
Weighted average period over which unrecognized compensation will be recognized (years) 2 years 3 months 11 days