Stock-Based Compensation Plans (Schedule of Compensation Expense Recognized in Connection with LTIP) (Details) (Long-Term Performance Share Plan [Member], USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Long-Term Performance Share Plan [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense $ 151 $ 200 $ 174
Related income tax benefit 53 70 61
Fair value of grants vested $ 0 $ 497 $ 609