Consolidated Statement Of Changes In Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock Preferred Stock - Series A	Preferred Stock Preferred Stock - Series B	Preferred Stock Preferred Stock - Series C	Common Stock	Additional Paid-In Capital	Retained (Deficit) Earnings	Treasury stock, held (in shares)	Accumulated Other Comprehensive Income Attributable to AT&T, net of tax	Noncontrolling Interest1
Balance at beginning of period at Dec. 31, 2021	$ 183,855	$ 0	$ 0	$ 0	$ 7,621	$ 130,112	$ 42,350	$ (17,280)	$ 3,529	$ 17,523
Balance at beginning of period (in shares) at Dec. 31, 2021		0	0	0	7,621			(480)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia						(6,832)	(45,041)
Repurchase and acquisition of common stock								$ (875)
Repurchase and acquisition of common stock (in shares)								(43)
Issuance/reissuance of treasury stock						(149)		$ (1,007)
Issuance/reissuance of treasury stock (in shares)								28
Share-based payments						(198)
Net income attributable to AT&T	14,993						14,993
Preferred stock dividends						0	(171)
Dividends, Common Stock, Cash						0	(6,004)
Other comprehensive income (loss) attributable to AT&T	(656)								(656)
Net income attributable to noncontrolling interest	1,107									1,107
Issuance and acquisition (disposition) by noncontrolling owners										0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests										(34)
Distributions										(1,024)
Balance at end of period at Sep. 30, 2022	139,978	$ 0	$ 0	$ 0	$ 7,621	122,933	6,127	$ (17,148)	2,873	17,572
Balance at end of period (in shares) at Sep. 30, 2022		0	0	0	7,621			(495)
Balance at beginning of period at Jun. 30, 2022	135,307	$ 0	$ 0	$ 0	$ 7,621	122,850	2,128	$ (17,160)	2,307	17,561
Balance at beginning of period (in shares) at Jun. 30, 2022		0	0	0	7,621			(495)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia						0	0
Repurchase and acquisition of common stock								$ (3)
Repurchase and acquisition of common stock (in shares)								0
Issuance/reissuance of treasury stock						(5)		$ (15)
Issuance/reissuance of treasury stock (in shares)								0
Share-based payments						(88)
Net income attributable to AT&T	6,026						6,026
Preferred stock dividends						0	(36)
Dividends, Common Stock, Cash						0	(1,991)
Other comprehensive income (loss) attributable to AT&T									566
Net income attributable to noncontrolling interest	373									373
Issuance and acquisition (disposition) by noncontrolling owners										0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests										(18)
Distributions										(344)
Balance at end of period at Sep. 30, 2022	139,978	$ 0	$ 0	$ 0	$ 7,621	122,933	6,127	$ (17,148)	2,873	17,572
Balance at end of period (in shares) at Sep. 30, 2022		0	0	0	7,621			(495)
Balance at beginning of period at Dec. 31, 2022	106,457	$ 0	$ 0	$ 0	$ 7,621	123,610	(19,415)	$ (17,082)	2,766	8,957
Balance at beginning of period (in shares) at Dec. 31, 2022		0	0	0	7,621			(493)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia						0	0
Repurchase and acquisition of common stock								$ (190)
Repurchase and acquisition of common stock (in shares)								(10)
Issuance/reissuance of treasury stock						(371)		$ (1,122)
Issuance/reissuance of treasury stock (in shares)								32
Share-based payments						(181)
Net income attributable to AT&T	12,212						12,212
Preferred stock dividends						(170)	0
Dividends, Common Stock, Cash						(5,998)	0
Other comprehensive income (loss) attributable to AT&T	(221)								(221)
Net income attributable to noncontrolling interest	829									787
Issuance and acquisition (disposition) by noncontrolling owners										5,180
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests										0
Distributions										(772)
Balance at end of period at Sep. 30, 2023	117,855	$ 0	$ 0	$ 0	$ 7,621	116,890	(7,203)	$ (16,150)	2,545	14,152
Balance at end of period (in shares) at Sep. 30, 2023		0	0	0	7,621			(471)
Balance at beginning of period at Jun. 30, 2023	116,075	$ 0	$ 0	$ 0	$ 7,621	118,833	(10,698)	$ (16,158)	2,305	14,172
Balance at beginning of period (in shares) at Jun. 30, 2023		0	0	0	7,621			(471)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distribution of WarnerMedia						0	0
Repurchase and acquisition of common stock								$ (1)
Repurchase and acquisition of common stock (in shares)								0
Issuance/reissuance of treasury stock						(3)		$ (9)
Issuance/reissuance of treasury stock (in shares)								0
Share-based payments						(93)
Net income attributable to AT&T	3,495						3,495
Preferred stock dividends						(36)	0
Dividends, Common Stock, Cash						(1,997)	0
Other comprehensive income (loss) attributable to AT&T									240
Net income attributable to noncontrolling interest	331									295
Issuance and acquisition (disposition) by noncontrolling owners										(1)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests										0
Distributions										(314)
Balance at end of period at Sep. 30, 2023	$ 117,855	$ 0	$ 0	$ 0	$ 7,621	$ 116,890	$ (7,203)	$ (16,150)	$ 2,545	$ 14,152
Balance at end of period (in shares) at Sep. 30, 2023		0	0	0	7,621			(471)