Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity, Stock Options and Net Income per Share - Stock Option Activity (Details)

v2.4.0.8
Shareholders' Equity, Stock Options and Net Income per Share - Stock Option Activity (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation $ 6,178 $ 6,050 $ 5,971
Employee Stock Option [Member]
      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Outstanding at beginning of year (shares) 2,874 3,363 3,702
Granted (shares) 118 94 117
Exercise of stock options (in shares) (1,260) (570) (451)
Forfeited (shares) 0 (13) (5)
Outstanding at end of year (shares) 1,732 2,874 3,363
Weighted Average Outstanding at beginning of year (per share) $ 26 $ 26 $ 26
Weighted average exercise price for options granted in the period $ 38 $ 37 $ 29
Weighted average exercise price for options exercised in the period $ 26 $ 27 $ 23
Weighted average exercise price for options forfeited in the period $ 0 $ 29 $ 24
Weighted Average Outstanding at end of year (per share) $ 27 $ 26 $ 26
Exercisable at end of year 1,514 2,487 2,585
Weighted average exercise price for options exercisable at year end $ 26 $ 26 $ 27
Weighted-average fair value of options granted during the year (dollars per share) $ 14 $ 13 $ 11
Aggregate intrinsic value of options exercised 15,477 3,924 3,771
Average aggregate intrinsic value for options outstanding 19,823    
Average aggregate instrinsic value for exercisable options 19,156    
Share-based compensation 1,410 2,585 3,981
Tax benefit related to share-based compensation expense 508 713 1,042
Unrecognized compensation cost 1,635    
Non-employee Director Stock Options [Member]
      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Outstanding at beginning of year (shares) 29 41 63
Exercise of stock options (in shares) (3) (12) (22)
Outstanding at end of year (shares) 26 29 41
Weighted Average Outstanding at beginning of year (per share) $ 23 $ 21 $ 22
Weighted average exercise price for options exercised in the period $ 20 $ 16 $ 23
Weighted Average Outstanding at end of year (per share) $ 23 $ 23 $ 21
Aggregate intrinsic value of options exercised 54 207 202
Average aggregate intrinsic value for options outstanding and exercisable $ 403    
Non-employee Director Activity - Options [Abstract]      
Weighted average remaining contractual term for options outstanding 1 year    
Term of options issued under the plan 10 years    
Exercise Price Range 22.47 thru 24.98 [Member] | Employee Stock Option [Member]
      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Outstanding at end of year (shares) 769    
Weighted Average Outstanding at end of year (per share) $ 22.67    
Exercisable at end of year 769    
Weighted average exercise price for options exercisable at year end $ 22.67    
Range of exercise price, lower range limit $ 22.47    
Range of exercise price, upper range limit $ 24.98    
Weighted average remaining contractual life 2 years 8 months 12 days    
Exercise Price Range 28.61 thru 31.65 [Member] | Employee Stock Option [Member]
      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Outstanding at end of year (shares) 751    
Weighted Average Outstanding at end of year (per share) $ 29.40    
Exercisable at end of year 713    
Weighted average exercise price for options exercisable at year end $ 29.44    
Range of exercise price, lower range limit $ 28.61    
Range of exercise price, upper range limit $ 31.65    
Weighted average remaining contractual life 1 year 4 months 24 days    
Exercise Price Range 36.55 thru 41.80 [Member] | Employee Stock Option [Member]
      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Outstanding at end of year (shares) 212    
Weighted Average Outstanding at end of year (per share) $ 37.13    
Exercisable at end of year 32    
Weighted average exercise price for options exercisable at year end $ 36.59    
Range of exercise price, lower range limit $ 36.55    
Range of exercise price, upper range limit $ 41.80    
Weighted average remaining contractual life 5 years 8 months 12 days    
Exercise Price Range 22.47 thru 41.80 [Member] | Employee Stock Option [Member]
      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Outstanding at end of year (shares) 1,732    
Weighted Average Outstanding at end of year (per share) $ 27.36    
Exercisable at end of year 1,514    
Weighted average exercise price for options exercisable at year end $ 26.14    
Range of exercise price, lower range limit $ 22.47    
Range of exercise price, upper range limit $ 41.80    
Weighted average remaining contractual life 2 years 6 months