Cover [Abstract] Cover [Abstract] Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Stock [Member] Common Shares (Par Value $1.00 Per Share) [Member] Series A Preferred Stock [Member] Depositary Shares, each representing a 1/1000th interest in a share of 5.000% Perpetual Preferred Stock, Series A [Member] Depositary Shares, each representing a 1/1000th interest in a share of 4.750% Perpetual Preferred Stock, Series C [Member] Depositary Shares, each representing a 1/1000th interest in a share of 4.750% Perpetual Preferred Stock, Series C [Member] ATT Inc 0.250% Global Notes Due March 4, 2026 [Member] AT&T Inc. 0.250% Global Notes due March 4, 2026 [Member] ATT Inc 1.800% Global Notes Due September 5, 2026 [Member] AT&T Inc. 1.800% Global Notes due September 5, 2026 [Member] ATT Inc 2.900% Global Notes Due December 4, 2026 [Member] AT&T Inc. 2.900% Global Notes due December 4, 2026 [Member] ATT Inc Floating Rate Global Notes Due September 16, 2027 [Member] AT&T Inc. Floating Rate Global Notes due September 16, 2027 [Member] ATT Inc 1.600% Global Notes Due May 19, 2028 [Member] AT&T Inc. 1.600% Global Notes due May 19, 2028 [Member] ATT Inc 2.350% Global Notes Due September 5, 2029 [Member] AT&T Inc. 2.350% Global Notes due September 5, 2029 [Member] ATT Inc 4.375% Global Notes Due September 14, 2029 [Member] AT&T Inc. 4.375% Global Notes due September 14, 2029 [Member] ATT Inc 2.600% Global Notes Due December 17, 2029 [Member] AT&T Inc. 2.600% Global Notes due December 17, 2029 [Member] ATT Inc 0.800% Global Notes Due March 4, 2030 [Member] AT&T Inc. 0.800% Global Notes due March 4, 2030 [Member] ATT Inc. 3.150% Global Notes Due June 1, 2030 [Member] AT&T Inc. 3.150% Global Notes due June 1, 2030 [Member] ATT Inc. 3.950% Global Notes due April 30, 2031 [Member] AT&T Inc. 3.950% Global Notes due April 30, 2031 [Member] ATT Inc 2.050% Global Notes Due May 19, 2032 [Member] AT&T Inc. 2.050% Global Notes due May 19, 2032 [Member] ATT Inc 3.550% Global Notes Due December 17, 2032 [Member] AT&T Inc. 3.550% Global Notes due December 17, 2032 [Member] ATT Inc 3.600% Global Notes Due June 1, 2033 [Member] AT&T Inc. 3.600% Global Notes due June 1, 2033 [Member] ATT Inc 5.200% Global Notes Due November 18, 2033 [Member] AT&T Inc. 5.200% Global Notes due November 18, 2033 [Member] ATT Inc 3.375% Global Notes Due March 15, 2034 [Member] AT&T Inc. 3.375% Global Notes due March 15, 2034 [Member] ATT Inc. 4.300% Global Notes due November 18, 2034 [Member] AT&T Inc. 4.300% Global Notes due November 18, 2034 [Member] ATT Inc 2.450% Global Notes Due March 15, 2035 [Member] AT&T Inc. 2.450% Global Notes due March 15, 2035 [Member] ATT Inc 3.150% Global Notes Due September 4, 2036 [Member] AT&T Inc. 3.150% Global Notes due September 4, 2036 [Member] ATT Inc 4.050% Global Notes Due June 1, 2037 [Member] AT&T Inc. 4.050% Global Notes due June 1, 2037 [Member] ATT Inc 2.600% Global Notes Due May 19, 2038 [Member] AT&T Inc. 2.600% Global Notes due May 19, 2038 [Member] ATT Inc 1.800% Global Notes Due September 14, 2039 [Member] AT&T Inc. 1.800% Global Notes due September 14, 2039 [Member] ATT Inc 7.000% Global Notes Due April 30, 2040 [Member] AT&T Inc. 7.000% Global Notes due April 30, 2040 [Member] ATT Inc 4.250% Global Notes Due June 1, 2043 [Member] AT&T Inc. 4.250% Global Notes due June 1, 2043 [Member] ATT Inc 4.875% Global Notes Due June 1, 2044 [Member] AT&T Inc. 4.875% Global Notes due June 1, 2044 [Member] ATT Inc 4.000% Global Notes Due June 1, 2049 [Member] AT&T Inc. 4.000% Global Notes due June 1, 2049 [Member] ATT Inc 4.250% Global Notes Due March 1, 2050 [Member] AT&T Inc. 4.250% Global Notes due March 1, 2050 [Member] ATT Inc 3.750% Global Notes Due September 1, 2050 [Member] AT&T Inc. 3.750% Global Notes due September 1, 2050 [Member] ATT Inc 5.350% Global Notes Due November 1, 2066 [Member] AT&T Inc. 5.350% Global Notes due November 1, 2066 [Member] Document Type Document Type Document Period End Date Document Period End Date Entity Registrant Name Entity Registrant Name Entity Incorporation State Country Code Entity Incorporation State Country Code Entity File Number Entity File Number Entity Tax Identification Number Entity Tax Identification Number Entity Address Address Line 1 Entity Address Address Line 1 Entity Address City Or Town Entity Address City Or Town Entity Address State Or Province Entity Address State Or Province Entity Address Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Written Communications Written Communications Soliciting Material Soliciting Material Pre Commencement Tender Offer Pre Commencement Tender Offer Pre Commencement Issuer Tender Offer Pre Commencement Issuer Tender Offer Security 12b Title Security 12b Title Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Emerging Growth Company Entity Emerging Growth Company Current Fiscal Year End Date Current Fiscal Year End Date Entity Central Index Key Entity Central Index Key Amendment Flag Amendment Flag