Stock-Based Compensation Plans (Schedule of Stock Option Activity) (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Number of Shares  
Options outstanding, beginning 111,950
Granted 4,500
Exercised (19,000)
Forfeited and expired (3,200)
Options outstanding, ending 94,250
Options exercisable 73,150
Weighted Average Exercise Price Per Share  
Options outstanding, beginning $ 33.36
Granted $ 35.22
Exercised $ 32.58
Forfeited and expired $ 38.32
Options outstanding, ending $ 33.44
Options exercisable $ 33.21
Weighted- Average Remaining Contractual Term  
Options outstanding 4 years 6 months
Options exercisable 3 years 9 months 18 days
Aggregate Intrinsic Value  
Options outstanding $ 664
Options exercisable $ 545