Property, Plant and Equipment Property, Plant and Equipment (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 site	Mar. 31, 2012
Property, Plant and Equipment [Line Items]
Number of cell sites to take off-air	9,600
Interest Costs Capitalized	$ 15	$ 115
Property, Plant and Equipment, Additions	450
Weighted Average [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	8 years
iDEN and CDMA [Member]
Property, Plant and Equipment [Line Items]
Depreciation	$ 360	$ 543