Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)
Sep. 30, 2012
Dec. 31, 2011
Stockholders' equity    
Preferred stock, par value (in dollars per share) $ 4 $ 4
Liquidation preference (in dollars per share) $ 1,000 $ 1,000
Preferred stock, shares authorized (in shares) 1,000,000 1,000,000
Preferred stock, shares issued (in shares) 14,738 14,738
Preferred stock, shares outstanding (in shares) 14,738 14,738
Common stock, par value (in dollars per share) $ 4 $ 4
Common stock, shares authorized (in shares) 10,000,000 10,000,000
Common stock, shares issued (in shares) 4,251,795 4,243,378
Common stock, shares outstanding (in shares) 4,251,795 4,243,378