Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments - Employee Activity Performance Shares (Details)

v3.19.1
Share-Based Payments - Employee Activity Performance Shares (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 3,047 $ 2,261
Key Employee Performance Share Based Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Period of years over which performance is calculated 3 years  
Percentage of grant based on meeting EBITDA per share targets 50.00%  
Percentage of grant based on three year performance of Company's TSR as compared to TSR of peer group 50.00%  
Minimum percentage of shares attainable based on EBITDA per share targets 0.00%  
Maximum percentage of shares attainable based on EBITDA per share targets 200.00%  
Minimum percentage of peer group by which Company share price must outperform before incremental performance shares are issued 25.00%  
Percentage of Peer Group By Which Company Share Price Must Outperform Before Maximum Incremental Shares Are Issued 90.00%  
Expected Stock Price Volatility Rate 23.40% 24.30%
Weighted Average Risk Free Interest Rate 2.50% 2.20%
Outstanding and non-vested, beginning of period (in shares) 65  
Grants in Period 27  
Shares Vested in Period (23)  
Outstanding and non-vested, end of period (in shares) 69  
Outstanding and non-vested, weighted-average grant date fair value, beginning of period $ 58  
Grants in Period, Weighted Average Grant Date Fair Value 61  
Vested in Period, Weighed-average grant date fair value 64  
Outstanding and non-vested, weighted-average grant date fair value, end of period $ 62  
Outstanding and non-vested, aggregate grant date fair value $ 4,318  
Share-based compensation expense 348 $ 335
Tax benefit related to share-based expense 83 86
Unrecognized share-based compensation, net of estimated forfeitures $ 2,806 $ 2,343
Weighted average period over which unrecognized compensation will be recognized (years) 2 years 3 months 11 days