Document and Entity Information
| Document and Entity Information | Feb. 01, 2022 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0000732717 |
| Document Type | 8-K |
| Document Period End Date | Feb. 1, 2022 |
| Entity Registrant Name | AT&T INC. |
| Entity Incorporation State 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 | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Shares (Par Value $1.00 Per Share) |
| Trading Symbol | T |
| Security Exchange Name | NYSE |
| Series A Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 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 |
| Series C Preferred Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 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 |
| ATT Inc 2650 Global Notes Due December 172021 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.650% Global Notes due December 17, 2021 |
| Trading Symbol | T 21B |
| Security Exchange Name | NYSE |
| ATT Inc 1450 Global Notes Due June 12022 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.450% Global Notes due June 1, 2022 |
| Trading Symbol | T 22B |
| Security Exchange Name | NYSE |
| ATT Inc 2500 Global Notes Due March 152023 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.500% Global Notes due March 15, 2023 |
| Trading Symbol | T 23 |
| Security Exchange Name | NYSE |
| ATT Inc 2750 Global Notes Due May 192023 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.750% Global Notes due May 19, 2023 |
| Trading Symbol | T 23C |
| Security Exchange Name | NYSE |
| ATT Inc Floating Rate Global Notes Due September 52023 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. Floating Rate Global Notes due September 5, 2023 |
| Trading Symbol | T 23D |
| Security Exchange Name | NYSE |
| Att Inc .1.050 Global Notes Due September 520233 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.050% Global Notes due September 5, 2023 |
| Trading Symbol | T 23E |
| Security Exchange Name | NYSE |
| Att Inc .1.300 Global Notes Due September 520231 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.300% Global Notes due September 5, 2023 |
| Trading Symbol | T 23A |
| Security Exchange Name | NYSE |
| ATT Inc 1950 Global Notes Due September 152023 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.950% Global Notes due September 15, 2023 |
| Trading Symbol | T 23F |
| Security Exchange Name | NYSE |
| ATT Inc 2400 Global Notes Due March 152024 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.400% Global Notes due March 15, 2024 |
| Trading Symbol | T 24A |
| Security Exchange Name | NYSE |
| ATT Inc 3500 Global Notes Due December 172025 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 3.500% Global Notes due December 17, 2025 |
| Trading Symbol | T 25 |
| Security Exchange Name | NYSE |
| ATT Inc 0250 Global Notes Due March 42026 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 0.250% Global Notes due March 4, 2026 |
| Trading Symbol | T 26E |
| Security Exchange Name | NYSE |
| Att Inc .1.800 Global Notes Due September 520265 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.800% Global Notes due September 5, 2026 |
| Trading Symbol | T 26D |
| Security Exchange Name | NYSE |
| ATT Inc 2900 Global Notes Due December 42026 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.900% Global Notes due December 4, 2026 |
| Trading Symbol | T 26A |
| Security Exchange Name | NYSE |
| ATT Inc 1600 Global Notes Due May 192028 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.600% Global Notes due May 19, 2028 |
| Trading Symbol | T 28C |
| Security Exchange Name | NYSE |
| ATT Inc 2350 Global Notes Due September 52029 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.350% Global Notes due September 5, 2029 |
| Trading Symbol | T 29D |
| Security Exchange Name | NYSE |
| Att Inc .4.375 Global Notes Due September 1420292 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 4.375% Global Notes due September 14, 2029 |
| Trading Symbol | T 29B |
| Security Exchange Name | NYSE |
| ATT Inc 2600 Global Notes Due December 172029 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.600% Global Notes due December 17, 2029 |
| Trading Symbol | T 29A |
| Security Exchange Name | NYSE |
| ATT Inc 0800 Global Notes Due March 42030 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 0.800% Global Notes due March 4, 2030 |
| Trading Symbol | T 30B |
| Security Exchange Name | NYSE |
| ATT Inc 2050 Global Notes Due May 192032 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.050% Global Notes due May 19, 2032 |
| Trading Symbol | T 32A |
| Security Exchange Name | NYSE |
| ATT Inc 3550 Global Notes Due December 172032 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 3.550% Global Notes due December 17, 2032 |
| Trading Symbol | T 32 |
| Security Exchange Name | NYSE |
| ATT Inc 5200 Global Notes Due November 182033 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 5.200% Global Notes due November 18, 2033 |
| Trading Symbol | T 33 |
| Security Exchange Name | NYSE |
| ATT Inc 3375 Global Notes Due March 152034 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 3.375% Global Notes due March 15, 2034 |
| Trading Symbol | T 34 |
| Security Exchange Name | NYSE |
| ATT Inc 2450 Global Notes Due March 152035 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.450% Global Notes due March 15, 2035 |
| Trading Symbol | T 35 |
| Security Exchange Name | NYSE |
| ATT Inc 3150 Global Notes Due September 42036 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 3.150% Global Notes due September 4, 2036 |
| Trading Symbol | T 36A |
| Security Exchange Name | NYSE |
| ATT Inc 2600 Global Notes Due May 192038 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 2.600% Global Notes due May 19, 2038 |
| Trading Symbol | T 38C |
| Security Exchange Name | NYSE |
| Att Inc .1.800 Global Notes Due September 1420394 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 1.800% Global Notes due September 14, 2039 |
| Trading Symbol | T 39B |
| Security Exchange Name | NYSE |
| ATT Inc 7000 Global Notes Due April 302040 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 7.000% Global Notes due April 30, 2040 |
| Trading Symbol | T 40 |
| Security Exchange Name | NYSE |
| ATT Inc 4250 Global Notes Due June 12043 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 4.250% Global Notes due June 1, 2043 |
| Trading Symbol | T 43 |
| Security Exchange Name | NYSE |
| ATT Inc 4875 Global Notes Due June 12044 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 4.875% Global Notes due June 1, 2044 |
| Trading Symbol | T 44 |
| Security Exchange Name | NYSE |
| ATT Inc 4000 Global Notes Due June 12049 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 4.000% Global Notes due June 1, 2049 |
| Trading Symbol | T 49A |
| Security Exchange Name | NYSE |
| ATT Inc 4250 Global Notes Due March 12050 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 4.250% Global Notes due March 1, 2050 |
| Trading Symbol | T 50 |
| Security Exchange Name | NYSE |
| ATT Inc 3750 Global Notes Due September 12050 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 3.750% Global Notes due September 1, 2050 |
| Trading Symbol | T 50A |
| Security Exchange Name | NYSE |
| ATT Inc 5350 Global Notes Due November 12066 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 5.350% Global Notes due November 1, 2066 |
| Trading Symbol | TBB |
| Security Exchange Name | NYSE |
| ATT Inc 5625 Global Notes Due August 12067 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | AT&T Inc. 5.625% Global Notes due August 1, 2067 |
| Trading Symbol | TBC |
| Security Exchange Name | NYSE |