Investments (Investee Summarized Income Statement Information) (Details) (Clearwire [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Clearwire [Member]
Revenues	$ 1,254	$ 535	$ 244
Equity Method Investment, Summarized Financial Information, Operating Expenses	3,645	2,698	1,384
Equity Method Investment, Summarized Financial Information, Operating Income (Loss)	(2,391)	(2,163)	(1,140)
Net loss before non-controlling interests	(2,856)	(2,251)	(1,209)
Equity Method Investment, Summarized Financial Information, Income (loss) from discontinued operations before non-controlling interests	$ (82)	$ (52)	$ (45)