Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets [Abstract]
Convertible preferred stock dividend rate	5.50%	5.50%
5-1/2 % convertible preferred stock, cumulative, voting, par value
5-1/2 % convertible preferred stock, cumulative, voting, shares authorized	2,000,000	2,000,000
5-1/2 % convertible preferred stock, cumulative, voting, shares issued	61,935	61,935
5-1/2 % convertible preferred stock, cumulative, voting, shares outstanding	61,935	61,935
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	25,277,548	25,141,610
Treasury stock, shares	3,188,039	3,175,638