Debt and Equity Transactions (Unaudited) Interest, Dividends and Maturities (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Long-term Debt, Fiscal Year Maturity [Abstract]
Remainder of 2013	$ 67,000,000		$ 67,000,000
2014	614,000,000		614,000,000
2015	1,100,000,000		1,100,000,000
2016	750,000,000		750,000,000
2017	700,000,000		700,000,000
Thereafter	17,900,000,000		17,900,000,000
Interest costs incurred	223,000,000	56,000,000	465,000,000	210,000,000
Interest costs capitalized	$ 61,000,000	$ 14,000,000	$ 114,000,000	$ 62,000,000