Acquisitions, Dispositions And Other Adjustments (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended				3 Months Ended	6 Months Ended
	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015
Acquisition and Dispositions [Line Items]
Acquisition of business - anticipated or actual cash paid to seller						$ 485	$ 20,954
DIRECTV [Member] | Acquisition [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - anticipated or actual acquisition period	Jul. 31, 2015
Acquisition of business - value/amount of assets acquired	$ 47,409
FCC Auction 97 [Member] | Acquisition [Member] | Spectrum Licenses [Member]
Acquisition and Dispositions [Line Items]
Acquisition of assets - anticipated or actual acquisition date			Jan. 31, 2015
Acquisition of intangible assets through a group purchase - value/amount of assets acquired			$ 18,189
Payments To Acquire Intangible Assets				$ 921	$ 17,268
GSF Telecom Holdings [Member] | Acquisition [Member]
Acquisition and Dispositions [Line Items]
Acquisition of assets - anticipated or actual acquisition date			Jan. 31, 2015
Acquistion of business - allocaton to debt, net of cash received by seller			$ 700
Acquisition of business - anticipated or actual cash paid to seller			2,500
GSF Telecom Holdings [Member] | Acquisition [Member] | Property, Plant and Equipment [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - value/amount of assets acquired			658
GSF Telecom Holdings [Member] | Acquisition [Member] | Customer lists and relationships [Member]
Acquisition and Dispositions [Line Items]
Acquisition of intangible assets - value/amount of assets acquired			378
GSF Telecom Holdings [Member] | Acquisition [Member] | Goodwill [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - value/amount of assets acquired			956
GSF Telecom Holdings [Member] | Acquisition [Member] | Spectrum Licenses [Member]
Acquisition and Dispositions [Line Items]
Acquisition of intangible assets - value/amount of assets acquired			735
GSF Telecom Holdings [Member] | Acquisition [Member] | Trade Names [Member]
Acquisition and Dispositions [Line Items]
Acquisition of intangible assets - value/amount of assets acquired			$ 26
Nextel Mexico [Member] | Acquisition [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - anticipated or actual acquisition period		Apr. 30, 2015
Acquistion of business - allocaton to debt, net of cash received by seller		$ 427
Acquisition of business - anticipated or actual cash paid to seller		1,875
Nextel Mexico [Member] | Acquisition [Member] | Property, Plant and Equipment [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - value/amount of assets acquired		1,167
Nextel Mexico [Member] | Acquisition [Member] | Customer lists and relationships [Member]
Acquisition and Dispositions [Line Items]
Acquisition of intangible assets - value/amount of assets acquired		128
Nextel Mexico [Member] | Acquisition [Member] | Goodwill [Member]
Acquisition and Dispositions [Line Items]
Acquisition of business - value/amount of assets acquired		193
Nextel Mexico [Member] | Acquisition [Member] | Spectrum Licenses [Member]
Acquisition and Dispositions [Line Items]
Acquisition of intangible assets - value/amount of assets acquired		$ 376