Consolidated Balance Sheets (Parenthetical) (USD $)
Jun. 30, 2012
Dec. 31, 2011
Consolidated Balance Sheets [Abstract]    
Common stock, par value $ 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 7,439,747 7,187,315