Cover
| Cover | Jun. 25, 2021 |
| Entity Information [Line Items] | |
| Document Type | 8-K/A |
| Document Period End Date | Jun. 25, 2021 |
| Entity Registrant Name | AT&T INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-08610 |
| Entity Tax Identification Number | 43-1301883 |
| Entity Address, Address Line One | 208 S. Akard St. |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75202 |
| City Area Code | 210 |
| Local Phone Number | 821-4105 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000732717 |
| Amendment Flag | true |
| Amendment Description | This Form 8-K/A amends the Form 8-K filed on June 25, 2021. |
| Common Shares (Par Value $1.00 Per Share) | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Shares (Par Value $1.00 Per Share) |
| Trading Symbol | T |
| Security Exchange Name | NYSE |
| Depositary Shares, each representing a 1/1000th interest in a share of 5.000% Perpetual Preferred Stock, Series A | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Depositary Shares, each representing a 1/1000th interest in a share of 5.000% Perpetual Preferred Stock, Series A |
| Trading Symbol | T PRA |
| Security Exchange Name | NYSE |
| Depositary Shares, each representing a 1/1000th interest in a share of 4.750% Perpetual Preferred Stock, Series C | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Depositary Shares, each representing a 1/1000th interest in a share of 4.750% Perpetual Preferred Stock, Series C |
| Trading Symbol | T PRC |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.650% Global Notes due December 17, 2021 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.650% Global Notes due December 17, 2021 |
| Trading Symbol | T 21B |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.450% Global Notes due June 1, 2022 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.450% Global Notes due June 1, 2022 |
| Trading Symbol | T 22B |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.500% Global Notes due March 15, 2023 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.500% Global Notes due March 15, 2023 |
| Trading Symbol | T 23 |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.750% Global Notes due May 19, 2023 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.750% Global Notes due May 19, 2023 |
| Trading Symbol | T 23C |
| Security Exchange Name | NYSE |
| AT&T Inc. Floating Rate Global Notes due September 5, 2023 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. Floating Rate Global Notes due September 5, 2023 |
| Trading Symbol | T 23D |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.050% Global Notes due September 5, 2023 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.050% Global Notes due September 5, 2023 |
| Trading Symbol | T 23E |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.300% Global Notes due September 5, 2023 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.300% Global Notes due September 5, 2023 |
| Trading Symbol | T 23A |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.950% Global Notes due September 15, 2023 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.950% Global Notes due September 15, 2023 |
| Trading Symbol | T 23F |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.400% Global Notes due March 15, 2024 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.400% Global Notes due March 15, 2024 |
| Trading Symbol | T 24A |
| Security Exchange Name | NYSE |
| AT&T Inc. 3.500% Global Notes due December 17, 2025 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 3.500% Global Notes due December 17, 2025 |
| Trading Symbol | T 25 |
| Security Exchange Name | NYSE |
| AT&T Inc. 0.250% Global Notes due March 4, 2026 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 0.250% Global Notes due March 4, 2026 |
| Trading Symbol | T 26E |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.800% Global Notes due September 5, 2026 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.800% Global Notes due September 5, 2026 |
| Trading Symbol | T 26D |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.900% Global Notes due December 4, 2026 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.900% Global Notes due December 4, 2026 |
| Trading Symbol | T 26A |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.600% Global Notes due May 19, 2028 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.600% Global Notes due May 19, 2028 |
| Trading Symbol | T 28C |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.350% Global Notes due September 5, 2029 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.350% Global Notes due September 5, 2029 |
| Trading Symbol | T 29D |
| Security Exchange Name | NYSE |
| AT&T Inc. 4.375% Global Notes due September 14, 2029 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 4.375% Global Notes due September 14, 2029 |
| Trading Symbol | T 29B |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.600% Global Notes due December 17, 2029 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.600% Global Notes due December 17, 2029 |
| Trading Symbol | T 29A |
| Security Exchange Name | NYSE |
| AT&T Inc. 0.800% Global Notes due March 4, 2030 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 0.800% Global Notes due March 4, 2030 |
| Trading Symbol | T 30B |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.050% Global Notes due May 19, 2032 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.050% Global Notes due May 19, 2032 |
| Trading Symbol | T 32A |
| Security Exchange Name | NYSE |
| AT&T Inc. 3.550% Global Notes due December 17, 2032 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 3.550% Global Notes due December 17, 2032 |
| Trading Symbol | T 32 |
| Security Exchange Name | NYSE |
| AT&T Inc. 5.200% Global Notes due November 18, 2033 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 5.200% Global Notes due November 18, 2033 |
| Trading Symbol | T 33 |
| Security Exchange Name | NYSE |
| AT&T Inc. 3.375% Global Notes due March 15, 2034 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 3.375% Global Notes due March 15, 2034 |
| Trading Symbol | T 34 |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.450% Global Notes due March 15, 2035 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.450% Global Notes due March 15, 2035 |
| Trading Symbol | T 35 |
| Security Exchange Name | NYSE |
| AT&T Inc. 3.150% Global Notes due September 4, 2036 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 3.150% Global Notes due September 4, 2036 |
| Trading Symbol | T 36A |
| Security Exchange Name | NYSE |
| AT&T Inc. 2.600% Global Notes due May 19, 2038 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 2.600% Global Notes due May 19, 2038 |
| Trading Symbol | T 38C |
| Security Exchange Name | NYSE |
| AT&T Inc. 1.800% Global Notes due September 14, 2039 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 1.800% Global Notes due September 14, 2039 |
| Trading Symbol | T 39B |
| Security Exchange Name | NYSE |
| AT&T Inc. 7.000% Global Notes due April 30, 2040 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 7.000% Global Notes due April 30, 2040 |
| Trading Symbol | T 40 |
| Security Exchange Name | NYSE |
| AT&T Inc. 4.250% Global Notes due June 1, 2043 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 4.250% Global Notes due June 1, 2043 |
| Trading Symbol | T 43 |
| Security Exchange Name | NYSE |
| AT&T Inc. 4.875% Global Notes due June 1, 2044 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 4.875% Global Notes due June 1, 2044 |
| Trading Symbol | T 44 |
| Security Exchange Name | NYSE |
| AT&T Inc. 4.000% Global Notes due June 1, 2049 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 4.000% Global Notes due June 1, 2049 |
| Trading Symbol | T 49A |
| Security Exchange Name | NYSE |
| AT&T Inc. 4.250% Global Notes due March 1, 2050 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 4.250% Global Notes due March 1, 2050 |
| Trading Symbol | T 50 |
| Security Exchange Name | NYSE |
| AT&T Inc. 3.750% Global Notes due September 1, 2050 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 3.750% Global Notes due September 1, 2050 |
| Trading Symbol | T 50A |
| Security Exchange Name | NYSE |
| AT&T Inc. 5.350% Global Notes due November 1, 2066 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 5.350% Global Notes due November 1, 2066 |
| Trading Symbol | TBB |
| Security Exchange Name | NYSE |
| AT&T Inc. 5.625% Global Notes due August 1, 2067 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | AT&T Inc. 5.625% Global Notes due August 1, 2067 |
| Trading Symbol | TBC |
| Security Exchange Name | NYSE |