Name:	t_ContractDuration
Namespace Prefix:	t_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Contract With Customer, Refund Liability, Construction Period

No definition available.

Name:	t_ContractWithCustomerRefundLiabilityConstructionPeriod
Namespace Prefix:	t_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Contract With Customer, Refund Liability, Expected Collection Period

No definition available.

Name:	t_ContractWithCustomerRefundLiabilityExpectedCollectionPeriod
Namespace Prefix:	t_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Contract With Customer, Refund Liability, Number Of Operating Capability Milestones

No definition available.

Name:	t_ContractWithCustomerRefundLiabilityNumberOfOperatingCapabilityMilestones
Namespace Prefix:	t_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Contract With Customer, Reinvestment Above Original Success-Based Payments, Expected Receivable

No definition available.

Name:	t_ContractWithCustomerReinvestmentAboveOriginalSuccessBasedPaymentsExpectedReceivable
Namespace Prefix:	t_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The First Responder Network Authoritys generally recurring costs associated with normal operations expenses adjusted for inflation over the life of the contract. This estimate was calculated by the reporting entity.

No definition available.

Name:	t_FirstResponderNetworkAuthorityOperatingExpensesAdjustedForInflation
Namespace Prefix:	t_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

Name:	t_GovernmentContractsSubjectToRenegotiationLineItems
Namespace Prefix:	t_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The total sustainability payment paid based on the number of states that have opted-in to the program.

No definition available.

Name:	t_SustainabilityPaymentAmount
Namespace Prefix:	t_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The total sustainability payment commitment paid based on the number of states that have opted-in to the program.

No definition available.

Name:	t_SustainabilityPaymentCommitmentAmount
Namespace Prefix:	t_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Sustainability Payment Commitment, Estimated Network Reinvestment Amount

No definition available.

Name:	t_SustainabilityPaymentCommitmentEstimatedNetworkReinvestmentAmount
Namespace Prefix:	t_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of liability for consideration received or receivable from customer which is not included in transaction price, when consideration is expected to be refunded to customer.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 55
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=118944142&loc=SL49130611-203046-203046

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of contractual obligation due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_ContractualObligationDueAfterFifthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of contractual obligation due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_ContractualObligationDueInFifthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of contractual obligation due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_ContractualObligationDueInFourthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of contractual obligation due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_ContractualObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of contractual obligation due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_ContractualObligationDueInSecondYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of contractual obligation due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_ContractualObligationDueInThirdYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045