Acquisitions, Dispositions And Other Adjustments (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended		0 Months Ended	7 Months Ended	0 Months Ended					1 Months Ended		9 Months Ended	0 Months Ended		9 Months Ended				0 Months Ended	1 Months Ended	0 Months Ended	1 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 13, 2014 Acquisition [Member] Leap Wireless International [Member]	Jul. 31, 2014 Acquisition [Member] Leap Wireless International [Member]	Mar. 13, 2014 Acquisition [Member] Leap Wireless International [Member] Licenses [Member]	Mar. 13, 2014 Acquisition [Member] Leap Wireless International [Member] Property, Plant and Equipment [Member]	Mar. 13, 2014 Acquisition [Member] Leap Wireless International [Member] Customer Lists [Member]	Mar. 13, 2014 Acquisition [Member] Leap Wireless International [Member] Goodwill [Member]	Mar. 13, 2014 Acquisition [Member] Leap Wireless International [Member] Trade Names [Member]	Oct. 31, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member]	May 31, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member]	Sep. 30, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member]	May 18, 2015 Acquisition [Member] Pending Approval [Member] DIRECTV [Member] Initial Period [Member]	Nov. 13, 2015 Acquisition [Member] Pending Approval [Member] DIRECTV [Member] Extended Period [Member]	Sep. 30, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member] Stock Price Scenario 1 [Member]	Sep. 30, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member] Stock Price Scenario 2 [Member] Minimum [Member]	Sep. 30, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member] Stock Price Scenario 2 [Member] Maximum [Member]	Sep. 30, 2014 Acquisition [Member] Pending Approval [Member] DIRECTV [Member] Stock Price Scenario 3 [Member]	Jun. 30, 2014 Disposition [Member] America Movil [Member]	May 31, 2014 Disposition [Member] America Movil [Member]	Oct. 24, 2014 Disposition [Member] Connecticut Wireline [Member]	Dec. 31, 2013 Disposition [Member] Connecticut Wireline [Member]	Jul. 31, 2014 Disposition [Member] Connecticut Wireline [Member] Federal Communication Commission [Member]	Oct. 15, 2014 Disposition [Member] Connecticut Wireline [Member] Connecticut Public Utilities Regulatory Authority [Member]
Business Acquisition [Line Items]
Acquisition of assets - anticipated or actual acquisition date			Mar. 13, 2014
Acquisition of assets - noncash consideration			one non-transferable contingent value right per share
Acquisition of business - end of termination rights period													May 18, 2015	Nov. 13, 2015
Acquisition of business - purchase price			$ 1,248
Acquisition of business - purchase price (in US dollars per share)			$ 15
Acquisition of business - preliminary value/amount of assets acquired					3,000	510	520	744	340
Long-Term Commitment - Description										In October 2014, DIRECTV and the National Football League renewed their agreement for the "NFL Sunday Ticket" service substantially on the terms discussed between AT&T and DIRECTV, satisfying one of the conditions to closing the merger.
Agreement date sale of equity method investment																				May 31, 2014
Debt redeemed or matured during period	(11,494)	(11,716)		3,889
Disposition of asset - agreement period																						2013-12
Disposal date of subsidiary/assets																			Jun. 30, 2014		Oct. 24, 2014
Total sales price (in U.S. dollars) of the company's investment in subsidiary																			5,566
Disposition of business - pretax gain recognized from sale of subsidiary/investment																			1,243
Dispositions	6,074	846																	4,565
Disposition of business - estimated cash to be received from sale of subsidiary/investment																						2,000
Long-term Debt, Fair Value			3,889
Regulatory Approval Date																							Jul. 31, 2014	Oct. 15, 2014
Pendiing Acquisitions Dispositions
Acquisition of business - agreement date or period											May 31, 2014
Acquisition of business - anticipated or actual acquisition period												first half of 2015
Acquisition of business - acquired entity's stockholder approval date												Sep. 25, 2014
Acquisition of business - purchase price											48,500
Acquisition of business - purchase price (in US dollars per share)											$ 95	$ 28.50
Acquisition of business - sellers debt, net of cash												$ 16,852
Acquisition of business - noncash consideration to be given															1.905 shares of AT&T stock per share of DIRECTV	1.724 shares of AT&T stock per share of DIRECTV	1.905 shares of AT&T stock per share of DIRECTV	1.724 shares of AT&T stock per share of DIRECTV
Acquisition of business - value of noncash consideration to be given (in US dollars per share)												$ 66.50			$ 34.90	$ 34.90	$ 38.58	$ 38.58