Other Financial Data (Accrued Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accrued Liabilities, Current [Abstract]
Deferred revenue	$ 788	$ 774
Billings in excess of costs and earnings	395	250
Compensation	290	471
Tax liabilities	93	126
Customer reserves	105	125
Dividend payable	63	70
Networks purchase price adjustment	0	96
Other	615	821
Accrued liabilities	$ 2,349	$ 2,733