Consolidated Statements Of Changes In Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings (Deficit)	Treasury Stock	Accumulated Other Comprehensive Income Attributable to AT&T, net of tax	Noncontrolling Interest	Preferred Stock Additional Paid-In Capital	Preferred Stock – Series A Preferred Stock	Preferred Stock – Series B Preferred Stock	Preferred Stock – Series C Preferred Stock	Common Stock Additional Paid-In Capital
Balance at beginning of year at Dec. 31, 2021	$ 183,855	$ 7,621	$ 130,112	$ 42,350	$ (17,280)	$ 3,529	$ 17,523		$ 0	$ 0	$ 0
Balance at beginning of year (in shares) at Dec. 31, 2021		7,621			(480)				0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia			(6,832)	(45,041)
Repurchase and acquisition of common stock					$ (890)
Repurchase and acquisition common stock (in shares)					(44)
Issuance of treasury stock			(171)		$ (1,088)
Issuance of treasury stock (in shares)					31
Share-based payments			(162)
Redemption or reclassification of interests held by noncontrolling owners			663				(5,997)
Net income (loss) attributable to AT&T	(8,524)			(8,524)
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings								$ 0				$ 0
Preferred stock dividends				(207)
Common stock dividends ($1.11, $1.11 and $1.11 per share in 2024, 2023 and 2022)				(7,993)
Other comprehensive income (loss) attributable to AT&T	(763)					(763)
Net income attributable to noncontrolling interest							1,469
Issuance and acquisition (disposition) of noncontrolling owners							(21)
Redemption of noncontrolling interest							(2,665)
Distributions							(1,352)
Balance at end of year at Dec. 31, 2022	106,457	$ 7,621	123,610	(19,415)	$ (17,082)	2,766	8,957		$ 0	$ 0	$ 0
Balance at end of year (in shares) at Dec. 31, 2022		7,621			(493)				0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia			0	0
Repurchase and acquisition of common stock					$ (194)
Repurchase and acquisition common stock (in shares)					(10)
Issuance of treasury stock			(379)		$ (1,148)
Issuance of treasury stock (in shares)					32
Share-based payments			(109)
Redemption or reclassification of interests held by noncontrolling owners			(407)				0
Net income (loss) attributable to AT&T	14,400			14,400
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings								205				7,991
Preferred stock dividends				0
Common stock dividends ($1.11, $1.11 and $1.11 per share in 2024, 2023 and 2022)				0
Other comprehensive income (loss) attributable to AT&T	(466)					(466)
Net income attributable to noncontrolling interest							1,146
Issuance and acquisition (disposition) of noncontrolling owners							5,180
Redemption of noncontrolling interest							(53)
Distributions							(1,085)
Balance at end of year at Dec. 31, 2023	117,442	$ 7,621	114,519	(5,015)	$ (16,128)	2,300	14,145		$ 0	$ 0	$ 0
Balance at end of year (in shares) at Dec. 31, 2023		7,621			(471)				0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia			0	0
Repurchase and acquisition of common stock					$ (215)
Repurchase and acquisition common stock (in shares)					(12)
Issuance of treasury stock			(516)		$ (1,320)
Issuance of treasury stock (in shares)					38
Share-based payments			(184)
Redemption or reclassification of interests held by noncontrolling owners			(557)				0
Net income (loss) attributable to AT&T	10,948			10,948
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings								$ 134				$ 4,020
Preferred stock dividends				(71)
Common stock dividends ($1.11, $1.11 and $1.11 per share in 2024, 2023 and 2022)				(3,991)
Other comprehensive income (loss) attributable to AT&T	(1,505)					(1,505)
Net income attributable to noncontrolling interest							1,163
Issuance and acquisition (disposition) of noncontrolling owners							(29)
Redemption of noncontrolling interest							(76)
Distributions							(1,330)
Balance at end of year at Dec. 31, 2024	$ 118,245	$ 7,621	$ 109,108	$ 1,871	$ (15,023)	$ 795	$ 13,873		$ 0	$ 0	$ 0
Balance at end of year (in shares) at Dec. 31, 2024		7,621			(445)				0	0	0