Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Stockholders' equity:
Common stock shares authorized (in shares)	500,000,000	500,000,000
Common stock par value (in dollars per share)	$ 1.00	$ 1.00
Common stock shares issued (in shares)	189,332,485	188,901,379
Treasury stock (in shares)	538,921	538,921