Segment Information (Reconciliation Of Operating Income Loss to Consolidated Statement Of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	$ 5,782	$ 6,012	$ 18,190	$ 16,505
Asset impairments and abandonments and restructuring	(604)	(114)	(604)	(745)
Interest expense	1,662	1,420	4,978	4,548
Equity in net income of affiliates	420	392	1,338	1,417
Other income (expense) — net	440	2,270	2,362	6,729
Income from Continuing Operations Before Income Taxes	4,980	7,254	16,912	20,103
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	7,244	6,926	21,095	19,912
Operating Segments | Communications
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	7,273	6,989	21,193	20,159
Operating Segments | Latin America
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	(29)	(63)	(98)	(247)
Corporate
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	(725)	(710)	(2,206)	(2,044)
Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction and other costs	(72)	(58)	(72)	(341)
Amortization of intangibles acquired	(21)	(16)	(55)	(60)
Asset impairments and abandonments and restructuring	(604)	(114)	(604)	(745)
Benefit-related gains (losses)	$ (40)	$ (16)	$ 32	$ (217)