The stated amount payable to holders if debt instrument is held to maturity debt security.

No definition available.

Name:	t_DebtInstrumentRedemptionAmount
Namespace Prefix:	t_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=t_NotesAndDebenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=t_DebtIssuedInForeignMarketsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=t_AnnualPutResetSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=t_ZeroCouponMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Debt (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2007
Debt Instrument [Line Items]
Debt instrument - redemption amount	$ 10,823
Weighted avg. coupon of our debt issuances during period	3.80%
Notes And Debentures [Member]
Debt Instrument [Line Items]
Weighted avg. coupon of our debt issuances during period	4.20%	4.00%
Debt Issued in Foreign Markets [Member]
Debt Instrument [Line Items]
Debt instrument - principal amount	$ 24,292	$ 26,221
Annual Put Reset Securities [Member]
Debt Instrument [Line Items]
Debt instrument - principal amount	$ 1,000
Debt instruments - maturity date	Apr. 30, 2021
Zero Coupon [Member]
Debt Instrument [Line Items]
Debt instrument - principal amount			$ 500
Debt instruments - maturity date	May 31, 2022
Debt instrument - redemption amount	$ 1,030