STATEMENT OF CONSOLIDATED SHAREHOLDERS' EQUITY (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income tax benefit (expense) to post retirement	$ 5	$ 7	$ (2)
Tax (benefit) expense to commodity hedges	(35)	66	62
Common stock, dividends, per share	$ 0.68	$ 0.60	$ 0.60
Retained Earnings [Member]
Common stock, dividends, per share	$ 0.68	$ 0.60	$ 0.60
Accumulated Other Comprehensive (Loss) [Member]
Income tax benefit (expense) to post retirement	5	7	(2)
Tax (benefit) expense to commodity hedges	$ (35)	$ 66	$ 62