Consolidated Balance Sheet (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	224,665,395	242,019,650
Common stock, shares outstanding	222,955,853	241,035,250