Derivative and Hedging Activities Interest Income and Interest Expense Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest Income (Expense), Net [Abstract]
Interest expense on senior notes	$ 180	$ 187	$ 560	$ 546
Interest expense on credit facilities	8	13	30	51
Interest expense on term loans	29	112	87	173
(Gains) losses on interest rate derivatives	(3)	(2)	51	(4)
Amortization of loan discount, issuance costs and other	21	24	70	67
Capitalized interest	(195)	(298)	(634)	(770)
Total interest expense	$ 40	$ 36	$ 164	$ 63