Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments - Stock Option Activity (Details)

v2.4.0.8
Share-Based Payments - Stock Option Activity (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation expense $ 1,676 $ 1,525 $ 5,005 $ 4,619
Employee Stock Option [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation expense 343 329 989 1,076
Tax benefit related to share-based expense 131 124 377 381
Unrecognized share-based compensation, net of estimated forfeitures 1,971 1,899 1,971 1,899
Employee activity - stock options [Abstract]        
Stock option grants expire (in years)     7 years  
Grants, vesting period (in years)     3 years  
Expected dividend yield (in hundredths)   1.20% 1.20% 1.20%
Expected stock price volatility   43.40% 38.80% 43.70%
Weighted Average Risk Free Interest Rate   1.50% 1.60% 0.90%
Expected life of options (in years)   4 years 6 months 11 days 5 years 3 months 11 days 5 years 3 months 11 days
Weighted-average fair value of options (dollars per share)   $ 13 $ 14 $ 13
Outstanding, beginning of period (in shares) 1,431,000   1,732,000  
Granted (in shares) 0   101,000  
Exercised (in shares) (51,000)   (445,000)  
Forfeited (in shares) 0   (8,000)  
Outstanding, end of period (in shares) 1,380,000   1,380,000  
Exercisable, end of period (in shares) 1,174,000   1,174,000  
Outstanding, beginning of period (in dollars per share) $ 28   $ 27  
Grants in Period (in dollars per share) $ 0   $ 43  
Exercises in Period (in dollars per share) $ 29   $ 28  
Forfeited in period (in dollars per share) $ 0   $ 38  
Outstanding, end of period (in dollars per share) $ 28   $ 28  
Exercisable, end of period (in dollars per share) $ 26   $ 26  
Aggregate Intrinsic Value Outstanding, end of period 25,745   25,745  
Aggregate Intrinsic Value Exercisable, end of period $ 24,377   $ 24,377  
Weighted-average remaining contractual term Outstanding, end of period (in years) 2 years 4 months 11 days   2 years 4 months 11 days  
Weighted-average remaining contractual term Exercisable, end of period (in years) 1 year 9 months 11 days   1 year 9 months 11 days  
Non-employee Director Stock Options [Member]
        
Employee activity - stock options [Abstract]        
Outstanding, end of period (in shares) 7,500   7,500  
Exercisable, end of period (in dollars per share) $ 26   $ 26  
Weighted-average remaining contractual term Outstanding, end of period (in years)     7 months 11 days  
Non-employee Director Activity - Options [Abstract]        
Terms of options granted to non-employee directors (in years)     10 years