Property, Plant And Equipment (Property, Plant And Equipment, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 17,801	$ 16,946
Less: Accumulated depreciation	(9,308)	(8,380)
Property, plant and equipment, net	8,493	8,566
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	151	147
Buildings and leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,327	1,326
Estimated useful lives	41 years
General support [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,146	1,037
General support [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	17 years
General support [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Central office/electronic circuit equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 6,244	5,934
Central office/electronic circuit equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	18 years
Central office/electronic circuit equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Poles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 712	672
Estimated useful lives	30 years
Cable and wire [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 7,280	6,973
Cable and wire [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Cable and wire [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	15 years
Conduit [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 515	509
Estimated useful lives	55 years
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 47	47
Other [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Other [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	12 years
Construction Work In Progress [Member]
Property, Plant and Equipment [Line Items]
Construction work in progress	$ 379	$ 301