Goodwill And Other Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill And Other Intangible Assets [Line Items]
Gross goodwill balance	$ 7,400,000,000	$ 7,100,000,000
Amortization of purchased intangibles	19,000,000	15,000,000	8,000,000
Estimated amortization expense for 2013 through 2015	30,000,000
Estimated amortization expense after 2015	29,000,000
Telecommunications [Member]
Goodwill And Other Intangible Assets [Line Items]
Accumulated impairment losses	$ 6,500,000,000	$ 6,500,000,000