Consolidated Condensed Balance Sheets (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Shareholders' equity:
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, $1.67 par value. Authorized 450,000,000 shares
Common stock, par value	$ 1.67	$ 1.67
Common stock, shares authorized	450,000,000	450,000,000
Series A Common Stock
Common stock, $1.67 par value. Authorized 450,000,000 shares
Common stock, shares issued	93,412,167	92,916,960
Series B Common Stock
Common stock, $1.67 par value. Authorized 450,000,000 shares
Common stock, shares issued	10,264,667	10,272,679