Quarterly report pursuant to Section 13 or 15(d)

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

v3.3.0.814
Share-Based Payments - Employee Activity Performance Shares (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation expense $ 1,886 $ 1,676 $ 5,562 $ 5,005
Key Employee Performance Share Based Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Period of Share Price Performance Comparison to Peer Group     3 years  
Minimum percentage of peer group by which Company share price must outperform before incremental performance shares are issued     30.00%  
Percentage of Peer Group By Which Company Share Price Must Outperform Before Maximum Incremental Shares Are Issued     90.00%  
Expected Stock Price Volatility Rate     23.50% 32.50%
Weighted Average Risk Free Interest Rate     1.00% 0.70%
Outstanding and non-vested, beginning of period (in shares) 77   74  
Grants in Period 0   27  
Additional Shares Awarded Based on Performance, Shares Issued in Period 0   0  
Shares Vested in Period 0   (24)  
Outstanding and non-vested, end of period (in shares) 77   77  
Outstanding and non-vested, weighted-average grant date fair value, beginning of period $ 52   $ 44  
Grants in Period, Weighted Average Grant Date Fair Value 0   67  
Stock Issued During Period, Weighted Average Grant Date Fair Value 0   0  
Vested in Period, Weighed-average grant date fair value 0   45  
Outstanding and non-vested, weighted-average grant date fair value, end of period $ 52   $ 52  
Outstanding and non-vested, aggregate grant date fair value $ 4,016   $ 4,016  
Share-based compensation expense 337 275 972 $ 822
Tax benefit related to share-based expense 132 105 380 313
Unrecognized share-based compensation, net of estimated forfeitures $ 2,062 $ 1,500 $ 2,062 $ 1,500