Segment Information (Reconciliation Of Operating Income Loss to Consolidated Statement Of Income) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	$ 6,560	$ 5,773	$ 13,691	$ 11,330
Interest Expense	1,258	932	2,465	1,831
Equity in net income of affiliates	28	33	41	33
Other income (expense) - net	91	48	161	118
Income Before Income Taxes	5,421	4,922	11,428	9,650
Operating Segments [Member] \| Business Solutions [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	4,201	4,232	8,500	8,374
Equity in net income of affiliates	0	0	0	0
Income Before Income Taxes	4,201	4,232	8,500	8,374
Operating Segments [Member] \| Entertainment Group [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	1,653	(196)	3,245	(460)
Equity in net income of affiliates	(2)	(12)	1	(18)
Income Before Income Taxes	1,651	(208)	3,246	(478)
Operating Segments [Member] \| Consumer Mobility [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	2,574	2,619	5,068	4,854
Equity in net income of affiliates	0	0	0	0
Income Before Income Taxes	2,574	2,619	5,068	4,854
Operating Segments [Member] \| International [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	(193)	(131)	(391)	(141)
Equity in net income of affiliates	9	0	23	0
Income Before Income Taxes	(184)	(131)	(368)	(141)
Operating Segments [Member] \| Segment Contribution [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	8,235	6,524	16,422	12,627
Equity in net income of affiliates	7	(12)	24	(18)
Income Before Income Taxes	8,242	6,512	16,446	12,609
Reconciling Items [Member] \| Corporate and Other [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	(97)	63	(218)	154
Reconciling Items [Member] \| Merger and intergration charges [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	(233)	(694)	(528)	(993)
Reconciling Items [Member] \| Amortization of intangibles acquired [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	(1,316)	(120)	(2,667)	(241)
Reconciling Items [Member] \| Employee separate charges [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	(29)	0	(54)	(217)
Reconciling Items [Member] \| Gain on wireless spectrum transactions [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	0	0	736	0
Reconciling Items [Member] \| Segment equity in net (income) loss of affiliates
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	$ (7)	$ 12	$ (24)	$ 18

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

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