Investments (Investee Summarized Financial Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Subsidiary or Equity Method Investee [Line Items]
Revenues	$ 317	$ 323	$ 640	$ 559
Operating Expenses	(628)	(1,234)	(1,373)	(2,118)
Operating loss	(311)	(911)	(733)	(1,559)
Net loss from continuing operations before non-controlling interests	(431)	(940)	(992)	(1,733)
Net loss from discontinued operations before non-controlling interests	$ (7)	$ (33)	$ (6)	$ (74)