Investments (Investee Summarized Financial Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Subsidiary or Equity Method Investee [Line Items]
Revenues	$ 314	$ 332	$ 954	$ 892
Operating Expenses	(647)	(731)	(2,020)	(2,850)
Operating loss	(333)	(399)	(1,066)	(1,958)
Net loss from continuing operations before non-controlling interests	(320)	(479)	(1,312)	(2,212)
Net loss from discontinued operations before non-controlling interests	$ (173)	$ (5)	$ (179)	$ (79)