Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.0.6
Share-Based Payments - Employee Activity Performance Shares (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 1,557 $ 1,606
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 34.50% 40.80%
Weighted Average Risk Free Interest Rate 0.40% 0.40%
Outstanding and non-vested, beginning of period (in shares) 62  
Grants in Period 26  
Shares Vested in Period 0  
Outstanding and non-vested, end of period (in shares) 88  
Outstanding and non-vested, weighted-average grant date fair value, beginning of period $ 36  
Grants in Period, Weighted Average Grant Date Fair Value $ 40  
Vested in Period, Weighed-average grant date fair value $ 0  
Outstanding and non-vested, weighted-average grant date fair value, end of period $ 37  
Outstanding and non-vested, aggregate grant date fair value 3,278  
Share-based compensation expense 233 147
Tax benefit related to share-based expense 89 57
Unrecognized share-based compensation, net of estimated forfeitures $ 2,012 $ 1,724