Debt (Summary Of Long-Term Debt Of AT&T And Its Subsidiaries) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 131,835	$ 143,347
Unamortized (discount) premium – net	(9,340)	(9,509)
Unamortized issuance costs	(379)	(436)
Total notes and debentures	122,116	133,402
Finance lease obligations	1,416	1,838
Total long-term debt, including current maturities	123,532	135,240
Current maturities of long-term debt	(5,089)	(7,386)
Total long-term debt	118,443	127,854
Fair value of interest rate swaps recorded in debt
Debt Instrument [Line Items]
Carrying amount of notes and debentures	6	7
Notes And Debentures Maturing Through 2033 [Member] \| Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 21,860	24,560
Notes And Debentures Maturing Through 2033 [Member] \| Notes and debentures \| Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	0.00%
Notes And Debentures Maturing Through 2033 [Member] \| Notes and debentures \| Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	2.99%
Notes And Debentures Maturing 2024-2061 \| Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 83,725	87,855
Notes And Debentures Maturing 2024-2061 \| Notes and debentures \| Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	3.00%
Notes And Debentures Maturing 2024-2061 \| Notes and debentures \| Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	4.99%
Notes And Debentures Maturing 2024-2095 \| Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 22,679	27,286
Notes And Debentures Maturing 2024-2095 \| Notes and debentures \| Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	5.00%
Notes And Debentures Maturing 2024-2095 \| Notes and debentures \| Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	6.99%
Notes And Debentures Maturing 2024-2097 \| Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 3,565	$ 3,639
Notes And Debentures Maturing 2024-2097 \| Notes and debentures \| Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	7.00%
Notes And Debentures Maturing 2024-2097 \| Notes and debentures \| Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	8.75%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt discount (premium).

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Present value of lessee's discounted obligation for lease payments from finance lease.

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