Consolidated Balance Sheets (Parenthetical) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Statement of Financial Position [Abstract]    
Common stock, par value (USD per share) $ 1.25 $ 1.25
Common stock, shares authorized 36,000,000 36,000,000
Common stock, shares issued 18,496,680 18,496,680
Treasury stock, shares at cost 7,717,403 7,671,475