Derivative And Hedging Activities (Interest Income And Interest Expense Disclosure) (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Derivative And Hedging Activities
Interest expense on senior notes	$ 164	$ 190	$ 342	$ 383
Interest expense on credit facilities	10	12	31	24
Gains (losses) on interest rate derivatives	19	(51)	18	(81)
Amortization of loan discount and other	8	12	23	23
Capitalized interest	(176)	(179)	(381)	(340)
Total interest (expense) income	$ 25	$ (16)	$ 33	$ 9