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
Mar. 31, 2014
Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 1,652 $ 1,557
Employee Stock Option [Member]
    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense 314 424
Tax benefit related to share-based expense 120 136
Unrecognized share-based compensation, net of estimated forfeitures 2,561 2,488
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%
Expected stock price volatility 40.60% 43.70%
Weighted Average Risk Free Interest Rate 1.60% 0.90%
Expected life of options (in years) 5 years 5 months 11 days 5 years 3 months 11 days
Weighted-average fair value of options (dollars per share) $ 15 $ 13
Outstanding, beginning of period (in shares) 1,732,000  
Granted (in shares) 91,000  
Exercised (in shares) (341,000)  
Forfeited (in shares) (8,000)  
Outstanding, end of period (in shares) 1,474,000  
Exercisable, end of period (in shares) 1,277,000  
Outstanding, beginning of period (in dollars per share) $ 27  
Grants in Period (in dollars per share) $ 43  
Exercises in Period (in dollars per share) $ 28  
Forfeited in period (in dollars per share) $ 38  
Outstanding, end of period (in dollars per share) $ 28  
Exercisable, end of period (in dollars per share) $ 26  
Aggregate Intrinsic Value Outstanding, end of period 23,812  
Aggregate Intrinsic Value Exercisable, end of period $ 22,948  
Weighted-average remaining contractual term Outstanding, end of period (in years) 2 years 9 months 11 days  
Weighted-average remaining contractual term Exercisable, end of period (in years) 2 years 2 months 11 days  
Non-employee Director Stock Options [Member]
    
Employee activity - stock options [Abstract]    
Outstanding, end of period (in shares) 15,000  
Exercisable, end of period (in dollars per share) $ 26  
Weighted-average remaining contractual term Outstanding, end of period (in years) 1 year 2 months 11 days  
Non-employee Director Activity - Options [Abstract]    
Terms of options granted to non-employee directors (in years) 10 years