AT&T (T) 10-K 19 Feb 20 2019 FY Annual report Financial data

Document Entity Information

Document Entity Information - USD ($) $ / shares in Units, $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 12, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Document Transition Report	false
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000732717
Entity File Number	001-8610
Entity Registrant Name	AT&T INC.
Entity Incorporation, State or Country Code	DE
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
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Shell Company	false
Share Price			$ 33.51
Entity Public Float			$ 245
Entity Common Stock, Shares Outstanding		7,172,884,070
Common Shares (Par Value $1.00 Per Share)
Entity Listings [Line Items]
Title of 12(b) Security	Common Shares (Par Value $1.00 Per Share)
Entity 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 Listings [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
Entity Trading Symbol	TPRA
Security Exchange Name	NYSE
Depositary Shares, each representing a 1/1000th interest in a share of 4.750% Perpetual Preferred Stock, Series C
Entity Listings [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
Entity Trading Symbol	TPRC
Security Exchange Name	NYSE
AT&T Inc. Floating Rate Due August 3 2020 Member [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. Floating Rate Global Notes due August 3, 2020
Entity Trading Symbol	T 20C
Security Exchange Name	NYSE
AT&T Inc. 1.875% Global Notes due December 4, 2020 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.875% Global Notes due December 4, 2020
Entity Trading Symbol	T 20
Security Exchange Name	NYSE
AT&T Inc. 2.650% Global Notes due December 17, 2021 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.650% Global Notes due December 17, 2021
Entity Trading Symbol	T 21B
Security Exchange Name	NYSE
AT&T Inc. 1.450% Global Notes due June 1, 2022 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.450% Global Notes due June 1, 2022
Entity Trading Symbol	T 22B
Security Exchange Name	NYSE
AT&T Inc. 2.500% Global Notes due March 15, 2023 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.500% Global Notes due March 15, 2023
Entity Trading Symbol	T 23
Security Exchange Name	NYSE
AT&T Inc. 2.750% Global Notes due May 19, 2023 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.750% Global Notes due May 19, 2023
Entity Trading Symbol	T 23C
Security Exchange Name	NYSE
AT&T Inc. Floating Rate Due September 5, 2023 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. Floating Rate Global Notes due September 5, 2023
Entity Trading Symbol	T 23D
Security Exchange Name	NYSE
AT&T Inc. 1.050% Global Notes due September 5, 2023 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.050% Global Notes due September 5, 2023
Entity Trading Symbol	T 23E
Security Exchange Name	NYSE
AT&T Inc. 1.300% Global Notes due September 5, 2023 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.300% Global Notes due September 5, 2023
Entity Trading Symbol	T 23A
Security Exchange Name	NYSE
AT&T Inc. 1.950% Global Notes due September 15, 2023 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.950% Global Notes due September 15, 2023
Entity Trading Symbol	T 23F
Security Exchange Name	NYSE
AT&T Inc. 2.400% Global Notes due March 15, 2024 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.400% Global Notes due March 15, 2024
Entity Trading Symbol	T 24A
Security Exchange Name	NYSE
AT&T Inc. 3.500% Global Notes due December 17, 2025 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.500% Global Notes due December 17, 2025
Entity Trading Symbol	T 25
Security Exchange Name	NYSE
AT&T Inc. 0.250% Global Notes due March 4, 2026 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 0.250% Global Notes due March 4, 2026
Entity Trading Symbol	T 26E
Security Exchange Name	NYSE
AT&T Inc. 1.800% Global Notes due September 5, 2026 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.800% Global Notes due September 5, 2026
Entity Trading Symbol	T 26D
Security Exchange Name	NYSE
AT&T Inc. 2.900% Global Notes due December 4, 2026 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.900% Global Notes due December 4, 2026
Entity Trading Symbol	T 26A
Security Exchange Name	NYSE
AT&T Inc. 4.375% Global Notes due September 14, 2029 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.375% Global Notes due September 14, 2029
Entity Trading Symbol	T 29B
Security Exchange Name	NYSE
AT&T Inc. 2.600% Global Notes due December 17, 2029 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.600% Global Notes due December 17, 2029
Entity Trading Symbol	T 29A
Security Exchange Name	NYSE
AT&T Inc. 0.800% Global Notes due March 4, 2030 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 0.800% Global Notes due March 4, 2030
Entity Trading Symbol	T 30B
Security Exchange Name	NYSE
AT&T Inc. 3.550% Global Notes due December 17, 2032 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.550% Global Notes due December 17, 2032
Entity Trading Symbol	T 32
Security Exchange Name	NYSE
AT&T Inc. 5.200% Global Notes due November 18, 2033 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 5.200% Global Notes due November 18, 2033
Entity Trading Symbol	T 33
Security Exchange Name	NYSE
AT&T Inc. 3.375% Global Notes due March 15, 2034 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.375% Global Notes due March 15, 2034
Entity Trading Symbol	T 34
Security Exchange Name	NYSE
AT&T Inc. 2.450% Global Notes Due March 15, 2035 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.450% Global Notes due March 15, 2035
Entity Trading Symbol	T 35
Security Exchange Name	NYSE
AT&T Inc. 3.150% Global Notes due September 4, 2036 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.150% Global Notes due September 4, 2036
Entity Trading Symbol	T 36A
Security Exchange Name	NYSE
AT&T Inc. 1.800% Global Notes due September 14, 2039 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.800% Global Notes due September 14, 2039
Entity Trading Symbol	T 39B
Security Exchange Name	NYSE
AT&T Inc. 7.000% Global Notes Due April 30, 2040 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 7.000% Global Notes due April 30, 2040
Entity Trading Symbol	T 40
Security Exchange Name	NYSE
AT&T Inc. 4.250% Global Notes due June 1, 2043 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.250% Global Notes due June 1, 2043
Entity Trading Symbol	T 43
Security Exchange Name	NYSE
AT&T Inc. 4.875% Global Notes due June 1, 2044 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.875% Global Notes due June 1, 2044
Entity Trading Symbol	T 44
Security Exchange Name	NYSE
AT&T Inc. 4.250% Global Notes due March 1, 2050 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.250% Global Notes due March 1, 2050
Entity Trading Symbol	T 50
Security Exchange Name	NYSE
AT&T Inc. 5.350% Global Notes due November 1, 2066 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 5.350% Global Notes due November 1, 2066
Entity Trading Symbol	TBB
Security Exchange Name	NYSE
AT&T Inc. 2.350% Global Notes due September 5, 2029 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.350% Global Notes due September 5, 2029
Entity Trading Symbol	T 29D
Security Exchange Name	NYSE
AT&T Inc. 5.625% Global Notes due August 1, 2067 [Member]
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 5.625% Global Notes due August 1, 2067
Entity Trading Symbol	TBC
Security Exchange Name	NYSE

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Revenues
Total operating revenues	$ 181,193	$ 170,756	$ 160,546
Operating Expenses
Other cost of revenues (exclusive of depreciation and amortization shown separately below)	34,356	32,906	37,942
Selling, general and administrative	39,422	36,765	35,465
Asset abandonments and impairments	1,458	46	2,914
Depreciation and amortization	28,217	28,430	24,387
Total operating expenses	153,238	144,660	140,576
Operating Income	27,955	26,096	19,970
Other Income (Expense)
Interest expense	(8,422)	(7,957)	(6,300)
Equity in net income (loss) of affiliates	(6)	48	128
Other income (expense) - net	(1,071)	6,782	1,597
Total other income (expense)	(9,487)	(1,223)	(4,831)
Income Before Income Taxes	18,468	24,873	15,139
Income tax (benefit) expense	3,493	4,920	(14,708)
Net Income	14,975	19,953	29,847
Less: Net Income Attributable to Noncontrolling Interest	(1,072)	(583)	(397)
Net Income Attributable to AT&T	13,903	19,370	29,450
Less: Preferred Stock Dividends	(3)	0	0
Net Income Attributable to Common Stock	$ 13,900	$ 19,370	$ 29,450
Basic Earnings Per Share Attributable to Common Stock	$ 1.90	$ 2.85	$ 4.77
Diluted Earnings Per Share Attributable to Common Stock	$ 1.89	$ 2.85	$ 4.76
Service
Operating Revenues
Total operating revenues	$ 163,499	$ 152,345	$ 145,597
Equipment
Operating Revenues
Total operating revenues	17,694	18,411	14,949
Operating Expenses
Cost of Goods and Services Sold	18,653	19,786	18,709
Broadcast, programming and operations
Operating Expenses
Cost of Goods and Services Sold	$ 31,132	$ 26,727	$ 21,159

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statements Of Comprehensive Income [Abstract]
Net Income	$ 14,975	$ 19,953	$ 29,847
Foreign Currency:
Translation adjustment (includes $(9), $(32) and $(5) attributable to noncontrolling interest), net of taxes of $18, $(45) and $123	19	(1,062)	15
Securities:
Net unrealized gains (losses), net of taxes of $17, $(1) and $109	50	(4)	187
Reclassification adjustment included in net income, net of taxes of $0, $0 and $(117)	0	0	(185)
Derivative Instruments:
Net unrealized gains (losses), net of taxes of $(240), $(156) and $200	(900)	(597)	371
Reclassification adjustment included in net income, net of taxes of $12, $6 and $21	45	13	39
Defined benefit postretirement plans:
Net prior service credit arising during period, net of taxes of $1,134, $271 and $675	3,457	830	1,083
Amortization of net prior service credit included in net income, net of taxes of $(475), $(431) and $(604)	(1,459)	(1,322)	(988)
Other comprehensive income (loss)	1,212	(2,142)	522
Total comprehensive Income	16,187	17,811	30,369
Less: Total comprehensive income attributable to noncontrolling interest	(1,063)	(551)	(392)
Total Comprehensive Income Attributable to AT&T	$ 15,124	$ 17,260	$ 29,977

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statements Of Comprehensive Income [Abstract]
Foreign currency translation adjustments, attributable to noncontrolling interest, net of taxes	$ (9)	$ (32)	$ (5)
Foreign currency translation adjustments, tax effect	18	(45)	123
Unrealized gains (losses) on securities, tax effect	17	(1)	109
Reclassification adjustment included in net income on securities, tax effect	0	0	(117)
Unrealized gains (losses) on derivative instruments, tax effect	(240)	(156)	200
Reclassification adjustment included in net income on derivative instruments, tax effect	12	6	21
Net prior service credit (cost) arising during period - tax effect	1,134	271	675
Amortization of net prior service cost (credit) included in net income, tax effect	$ (475)	$ (431)	$ (604)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 12,130	$ 5,204
Accounts receivable - net of allowances for doubtful accounts of $1,235 and $907	22,636	26,472
Prepaid expenses	1,631	2,047
Other current assets	18,364	17,704
Total current assets	54,761	51,427
Noncurrent inventories and theatrical film and television production costs	12,434	7,713
Property, Plant and Equipment - Net	130,128	131,473
Goodwill	146,241	146,370
Licenses - Net	97,907	96,144
Indefinite-Lived Intangible Assets (Excluding Goodwill)	101,392	102,418
Other Intangible Assets - Net	20,798	26,269
Investments In and Advances to Equity Affiliates	3,695	6,245
Operating lease right-of-use assets	24,039	0
Other Assets	22,754	24,809
Total Assets	551,669	531,864
Current Liabilities
Debt maturing within one year	11,838	10,255
Accounts payable and accrued liabilities	45,956	43,184
Advanced billings and customer deposits	6,124	5,948
Accrued taxes	1,212	1,179
Dividends payable	3,781	3,854
Total current liabilities	68,911	64,420
Long-Term Debt	151,309	166,250
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes	59,502	57,859
Postemployment benefit obligation	18,788	19,218
Operating lease liabilities	21,804	0
Other noncurrent liabilities	29,421	30,233
Total deferred credits and other noncurrent liabilities	129,515	107,310
Stockholders' Equity
Preferred stock ($1 par value, 5% cumulative, 10,000,000 authorized, 48,000 shares issued and outstanding at December 31, 2019 and 0 issued and outstanding at December 31, 2018	0	0
Common stock ($1 par value, 14,000,000,000 authorized at December 31, 2019 and December 31, 2018: issued 7,620,748,598 at December 31, 2019 and December 31, 2018)	7,621	7,621
Additional paid-in capital	126,279	125,525
Retained earnings	57,936	58,753
Treasury stock (366,193,458 at December 31, 2019 and 339,120,073 at December 31, 2018, at cost)	(13,085)	(12,059)
Accumulated other comprehensive income	5,470	4,249
Noncontrolling interest	17,713	9,795
Total stockholders' equity	201,934	193,884
Total Liabilities and Stockholders' Equity	551,669	531,864
Trademarks And Tradenames - Net
Current Assets
Indefinite-Lived Intangible Assets (Excluding Goodwill)	23,567	24,345
Distribution Networks - Net
Current Assets
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 15,345	$ 17,069

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Allowances for doubtful accounts	$ 1,235	$ 907
Preferred stock, par value	$ 1
Preferred stock, dividend rate	5.00%
Preferred stock, authorized (in shares)	10,000,000
Preferred stock, issued (in shares)	48,000	0
Preferred stock, outstanding (in shares)	48,000	0
Common stock, par value	$ 1	$ 1
Common stock, authorized	14,000,000,000	14,000,000,000
Common stock, issued	7,620,748,598	7,620,748,598
Treasury stock, held	366,193,458	339,120,073

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net Income	$ 14,975	$ 19,953	$ 29,847
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	28,217	28,430	24,387
Amortization of film and television costs	9,587	3,772	0
Undistributed earnings from investments in equity affiliates	295	292	174
Provision for uncollectible accounts	2,575	1,791	1,642
Deferred income tax expense (benefit)	1,806	4,931	(15,265)
Net (gain) loss from sale of investments, net of impairments	(1,218)	(739)	(282)
Pension and postretirement benefit expense (credit)	(2,002)	(1,148)	(1,031)
Actuarial (gain) loss on pension and postretirement benefits	5,171	(3,412)	1,258
Asset abandonments and impairments	1,458	46	2,914
Changes in operating assets and liabilities:
Receivable	2,812	(1,580)	(986)
Other current assets inventories and theatrical film and television production costs	(12,852)	(6,442)	(778)
Accounts payable and other accrued liabilities	(1,524)	1,602	816
Equipment installment receivables and related sales	548	(490)	(1,239)
Deferred customer contract acquisition and fulfillment costs	(910)	(3,458)	(1,422)
Postretirement claims and contributions	(1,008)	(936)	(2,064)
Other - net	738	990	39
Total adjustments	33,693	23,649	8,163
Net Cash Provided by Operating Activities	48,668	43,602	38,010
Investing Activities
Purchase of property and equipment	(19,435)	(20,758)	(20,647)
Interest during construction	(200)	(493)	(903)
Acquisitions, net of cash acquired	(1,809)	(43,309)	1,123
Disposition	4,684	2,148	59
(Purchases) sales and settlement of of securities and investments, net	435	(183)	449
Advances to and investments in equity affiliates	(365)	(1,050)	0
Cash collections of deferred purchase price	0	500	976
Net Cash Used in Investing Activities	(16,690)	(63,145)	(18,943)
Financing Activities
Net change in short-term borrowings with original maturities of three months or less	(276)	(821)	(2)
Issuance of other short-term borrowings	4,012	4,898	0
Repayment of other short-term borrowings	(6,904)	(2,098)	0
Issuance of long-term debt	17,039	41,875	48,793
Repayment of long-term debt	(27,592)	(52,643)	(12,339)
Payment of vendor financing	(3,050)	(560)	(572)
Issuance of preferred stock	1,164	0	0
Purchase of treasury stock	(2,417)	(609)	(463)
Issuance of treasury stock	631	745	33
Issuance of preferred interest in subsidiary	7,876	0	0
Dividends paid	(14,888)	(13,410)	(12,038)
Other	(678)	(3,366)	2,518
Net Cash (Used in) Provided by Financing Activities	(25,083)	(25,989)	25,930
Net increase (decrease) in cash and cash equivalents and restricted cash	6,895	(45,532)	44,997
Cash and cash equivalents and restricted cash beginning of year	5,400	50,932	5,935
Cash and Cash Equivalents and Restricted Cash End of Year	$ 12,295	$ 5,400	$ 50,932

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]Preferred Stock [Member]	Additional Paid-In Capital [Member]Common Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member]Preferred Stock [Member]	Retained Earnings [Member]Common Stock [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income Attributable To AT&T, Net Of Tax [Member]	Noncontrolling Interest [Member]
Balance at beginning of year at Dec. 31, 2016	$ 124,110	$ 0	$ 6,495	$ 89,604			$ 34,734			$ (12,659)	$ 4,961	$ 975
Balance at beginning of year (in shares) at Dec. 31, 2016		0	6,495							(356)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (value)		$ 0	$ 0		$ 0	$ 0
Issuance of stock (in shares)		0	0
Issuance of treasury stock				2						$ 496
Issuance of treasury stock (in shares)										14
Share-based payments				(43)
Changes related to acquisitions of interest held by noncontrolling owners				0
Repurchase and acquisition of common stock										$ (551)
Repurchase and acquisition common stock (in shares)										(14)
Net income attributable to AT&T ($1.89, $2.85 and $4.76 per diluted share)	29,450						29,450
Dividends to stockholders ($2.05, $2.01 and $1.97 per share)								$ 0	$ (12,157)
Other comprehensive income (loss) attributable to AT&T	527										527
Net income attributable to noncontrolling interest	397											397
Interest acquired by noncontrolling owners												0
Acquisitions of noncontrolling interests												140
Distributions												(361)
Acquisition of interests held by noncontrolling owners												0
Translation adjustments attributable to noncontrolling interest, net of taxes	(5)											(5)
Balance at end of year at Dec. 31, 2017	142,007	$ 0	$ 6,495	89,563			50,500			$ (12,714)	7,017	1,146
Balance at end of year (in shares) at Dec. 31, 2017		0	6,495							(356)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (value)		$ 0	$ 1,126		0	35,473
Issuance of stock (in shares)		0	1,126
Issuance of treasury stock				(115)						$ 1,347
Issuance of treasury stock (in shares)										37
Share-based payments				604
Changes related to acquisitions of interest held by noncontrolling owners				0
Repurchase and acquisition of common stock										$ (692)
Repurchase and acquisition common stock (in shares)										(20)
Net income attributable to AT&T ($1.89, $2.85 and $4.76 per diluted share)	19,370						19,370
Dividends to stockholders ($2.05, $2.01 and $1.97 per share)								0	(14,117)
Other comprehensive income (loss) attributable to AT&T	(2,110)										(2,110)
Net income attributable to noncontrolling interest	583											583
Interest acquired by noncontrolling owners												8,803
Acquisitions of noncontrolling interests												1
Distributions												(732)
Acquisition of interests held by noncontrolling owners												(9)
Translation adjustments attributable to noncontrolling interest, net of taxes	(32)											(32)
Balance at end of year at Dec. 31, 2018	193,884	$ 0	$ 7,621	125,525			58,753			$ (12,059)	4,249	9,795
Balance at end of year (in shares) at Dec. 31, 2018		0	7,621							(339)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock (value)		$ 0	$ 0		$ 1,164	$ 0
Issuance of stock (in shares)		0	0
Issuance of treasury stock				(125)						$ 1,466
Issuance of treasury stock (in shares)										40
Share-based payments				(271)
Changes related to acquisitions of interest held by noncontrolling owners				(14)
Repurchase and acquisition of common stock										$ (2,492)
Repurchase and acquisition common stock (in shares)										(67)
Net income attributable to AT&T ($1.89, $2.85 and $4.76 per diluted share)	13,903						13,903
Dividends to stockholders ($2.05, $2.01 and $1.97 per share)								$ (8)	$ (15,028)
Other comprehensive income (loss) attributable to AT&T	1,221										1,221
Net income attributable to noncontrolling interest	1,072											1,072
Interest acquired by noncontrolling owners												7,876
Acquisitions of noncontrolling interests												5
Distributions												(1,055)
Acquisition of interests held by noncontrolling owners												0
Translation adjustments attributable to noncontrolling interest, net of taxes	(9)											(9)
Balance at end of year at Dec. 31, 2019	$ 201,934	$ 0	$ 7,621	$ 126,279			$ 57,936			$ (13,085)	$ 5,470	$ 17,713
Balance at end of year (in shares) at Dec. 31, 2019		0	7,621							(366)

Consolidated Statements Of Ch_2

Consolidated Statements Of Changes In Stockholders' Equity (Parenthetical) - $ / shares

1 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2019

[1]

Sep. 30, 2019

[1]

Jun. 30, 2019

[1]

Mar. 31, 2019

[1]

Dec. 31, 2018

[1]

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Consolidated Statements Of Changes In Stockholders' Equity

Net income attributable to AT&T, per diluted share

$ 0.33

$ 0.50

$ 0.51

$ 0.56

$ 0.66

$ 0.65

$ 0.81

$ 0.75

$ 0.65

$ 0.81

$ 0.75

$ 1.89

$ 2.85

$ 4.76

Dividends to stockholders, per share

$ 0.52

$ 0.51

$ 2.05

$ 2.01

$ 1.97

[1]

Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year.

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Summary Of Significant Accounting Policies
Basis of Presentation and Significant Accounting Policies [Text Block]	NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation Throughout this document, AT&T Inc. is referred to as “AT&T,” “we” or the “Company.” The consolidated financial statements include the accounts of the Company and our majority-owned subsidiaries and affiliates, including the results of Time Warner Inc. (referred to as “Time Warner” or “WarnerMedia”), which was acquired on June 14, 2018 (see Note 6). AT&T is a holding company whose subsidiaries and affiliates operate worldwide in the telecommunications, media and technology industries. All significant intercompany transactions are eliminated in the consolidation process. Investments in less than majority-owned subsidiaries and partnerships where we have significant influence are accounted for under the equity method. Earnings from certain investments accounted for using the equity method are included for periods ended within up to one quarter of our period end. We also record our proportionate share of our equity method investees’ other comprehensive income (OCI) items, including translation adjustments. We treat distributions received from equity method investees as returns on investment and classify them as cash flows from operating activities until those distributions exceed our cumulative equity in the earnings of that investment. We treat the excess amount as a return of investment and classify it as cash flows from investing activities. The preparation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes, including estimates of probable losses and expenses. Actual results could differ from those estimates. Certain prior period amounts have been conformed to the current period’s presentation. See Note 4 for a discussion on the recast of our segment results. Accounting Policies and Adopted Accounting Standards Leases As of January 1, 2019, we adopted, with modified retrospective The key change upon adoption of the standard was balance sheet recognition, given that the recognition of lease expense on our income statement is similar to our historical accounting. Using the modified retrospective transition method of adoption, we did not adjust the balance sheet for comparative periods practical expedients The adoption of ASC 842 resulted in the recognition of an operating lease liability of $ 22,121 20,960. The cumulative effect of the adoption to retained earnings was an increase of $ 316 reflecting the reclassification of deferred gains related to sale/leaseback transactions. The standard did not materially impact our income statements or statements of cash flows Deferral of Episodic Television and Film Costs In March 2019, the FASB issued ASU No. 2019-02, “ Entertainment—Films—Other Assets—Film Costs (Subtopic 926-20) and Entertainment—Broadcasters—Intangibles—Goodwill and Other (Subtopic 920-350): Improvements to Accounting for Costs of Films and License Agreements for Program Materials” (ASU 2019-02), which we early adopted January 1, 2019 , with prospective programming inventory were eliminated. As of January 1, 2019, we reclassified $ 2,274 This change in accounting does not materially impact our income statement . Revenue Recognition As of January 1, 2018 , we adopted ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” as modified (ASC 606), using the modified retrospective does not allow us to adjust prior periods 2,342 to retained earnings for the cumulative effect of the change, with an offsetting contract asset of $ 1,737, deferred contract acquisition costs of $ 1,454, other asset reductions of $ 239, other liability reductions of $ 212, deferred income tax liability of $ 787 and increase to noncontrolling interest of $ 35. (See Note 5) Financial Instruments As of January 1, 2018 , we adopted ASU No. 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01), which requires us to prospectively 658 Income Taxes We record deferred income taxes for temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the computed tax basis of those assets and liabilities. We record valuation allowances against the deferred tax assets (included, together with our deferred income tax assets, as part of our reportable net deferred income tax liabilities on our consolidated balance sheets), for which the realization is uncertain. We review these items regularly in light of changes in federal and state tax laws and changes in our business. The Tax Cuts and Jobs Act (the Act) was enacted on December 22, 2017. The Act reduced the U.S. federal corporate income tax rate from 35% to 21% and required companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred. Recognizing the late enactment of the Act and complexity of accurately accounting for its impact, the Securities and Exchange Commission (SEC) in Staff Accounting Bulletin (SAB) 118 provided guidance that allowed registrants to provide a reasonable estimate of the impact to their financial statements and adjust the reported impact in a measurement period not to exceed one year. We included the estimated impact of the Act in our financial results at or for the period ended December 31, 2017, with additional adjustments recorded in 2018. (See Note 14) In February 2018, the FASB issued ASU No. 2018-02, “Income Statement– Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (ASU 2018-02), which allows entities the option to reclassify from accumulated OCI to retained earnings the stranded tax effects resulting from the application of the Act. We elected to adopt ASU 2018-02 in the period in which the estimated income tax effects of the Act were recognized, reflecting a $ 1,529 adjustment for 2017 in the consolidated statements of changes in stockholders’ equity. (See Note 3) Cash and Cash Equivalents Cash and cash equivalents include all highly liquid investments with original maturities of three months or less. The carrying amounts approximate fair value. At December 31, 2019, we held $ 2,654 in cash and $ 9,476 in money market funds and other cash equivalents. Of our total cash and cash equivalents, $ 2,681 resided in foreign jurisdictions, some of which is subject to restrictions on repatriation. Allowance for Doubtful Accounts We record expense to maintain an allowance for doubtful accounts for estimated losses that result from the failure or inability of our customers to make required payments deemed collectible from the customer when the service was provided or product was delivered. When determining the allowance, we consider the probability of recoverability of accounts receivable based on past experience, taking into account current collection trends as well as general economic factors, including bankruptcy rates. Credit risks are assessed based on historical write-offs, net of recoveries, as well as an analysis of the aged accounts receivable balances with allowances generally increasing as the receivable ages. Accounts receivable may be fully reserved for when specific collection issues are known to exist, such as catastrophes or pending bankruptcies. Equipment Inventory Equipment inventories, which primarily consist of wireless devices and accessories, are included in “Other current assets” on our consolidated balance sheets. Equipment inventories are valued at the lower of cost or net realizable value and were $ 2,864 at December 31, 2019 and $ 2,771 at December 31, 2018. Licensed Programming Inventory Cost Recognition and Impairment We enter into agreements to license programming exhibition rights from licensors. A programming inventory asset related to these rights and a corresponding liability payable to the licensor are recorded (on a discounted basis if the license agreements are long-term) when (i) the cost of the programming is reasonably determined, (ii) the programming material has been accepted in accordance with the terms of the agreement, (iii) the programming is available for its first showing or telecast, and (iv) the license period has commenced. There are variations in the amortization methods of these rights, depending on whether the network is advertising-supported (e.g., TNT and TBS) or not advertising-supported (e.g., HBO and Turner Classic Movies). For the advertising-supported networks, our general policy is to amortize each program’s costs on a straight-line basis (or per-play basis, if greater) over its license period. In circumstances where the initial airing of the program has more value than subsequent airings, an accelerated method of amortization is used. The accelerated amortization upon the first airing versus subsequent airings is determined based on a study of historical and estimated future advertising sales for similar programming. For rights fees paid for sports programming arrangements, such rights fees are amortized using a revenue-forecast model, in which the rights fees are amortized using the ratio of current period advertising revenue to total estimated remaining advertising revenue over the term of the arrangement. For premium pay television, streaming and over-the-top (OTT) services that are not advertising-supported, each licensed program’s costs are amortized on a straight-line basis over its license period or estimated period of use, beginning with the month of initial exhibition. When we have the right to exhibit feature theatrical programming in multiple windows over a number of years, historical audience viewership is used as the basis for determining the amount of programming amortization attributable to each window. Licensed programming inventory is carried at the lower of unamortized cost or fair value. For networks that generate both advertising and subscription revenues, the net realizable value of unamortized programming costs is generally evaluated based on the network’s programming taken as a whole. In assessing whether the programming inventory for a particular advertising-supported network is impaired, the net realizable value for all of the network’s programming inventory is determined based on a projection of the network’s profitability. This assessment would occur upon the occurrence of certain triggering events. Similarly, for premium pay television, streaming and OTT services that are not advertising-supported, an evaluation of the fair value of unamortized programming costs is performed based on services’ licensed programming taken as a whole. Specifically, the fair value for all premium pay television, streaming and OTT service licensed programming is determined based on projections of estimated subscription revenues less certain costs of delivering and distributing the licensed programming. Changes in management’s intended usage of a specific program, such as a decision to no longer exhibit that program and forgo the use of the rights associated with the program license, results in a reassessment of that program’s fair value, which could result in an impairment. (See Note 11) Film and Television Production Cost Recognition, Participations and Residuals and Impairments Film and television production costs on our consolidated balance sheets include the unamortized cost of completed theatrical films and television episodes, theatrical films and television series in production and undeveloped film and television rights. Film and television production costs are stated at the lower of cost, less accumulated amortization, or fair value. For films and television programs predominantly monetized individually, the amount of capitalized film and television production costs and the amount of participations and residuals to be recognized as broadcast, programming and operations expenses for a given film or television series in a particular period was determined using the film forecast computation method. Under this method, the amortization of capitalized costs and the accrual of participations and residuals was based on the proportion of the film’s (or television program’s) revenues recognized for such period to the film’s (or television program’s) estimated remaining ultimate revenues (i.e., the total revenue to be received throughout a film’s (or television program’s) life cycle). The process of estimating a film’s ultimate revenues requires us to make a series of judgments related to future revenue-generating activities associated with a particular film. We estimate the ultimate revenues, less additional costs to be incurred (including exploitation and participation costs), in order to determine whether the value of a film or television series is impaired and requires an immediate write-off of unrecoverable film and television production costs. To the extent that the ultimate revenues are adjusted, the resulting gross margin reported on the exploitation of that film or television series in a period is also adjusted. Prior to the theatrical release of a film, our estimates are based on factors such as the historical performance of similar films, the star power of the lead actors, the rating and genre of the film, pre-release market research (including test market screenings), international distribution plans and the expected number of theaters in which the film will be released. In the absence of revenues directly related to the exhibition of owned film or television programs on our television networks, premium pay television, streaming or OTT services, we estimate a portion of the unamortized costs that are representative of the utilization of that film or television program in that exhibition and expense such costs as the film or television program is exhibited. The period over which ultimate revenues are estimated was generally not to exceed ten years from the initial release of a motion picture or from the date of delivery of the first episode of an episodic television series. Estimates were updated based on information available during the film’s production and, upon release, the actual results of each film. For a film (or television program) predominantly monetized as part of a film (or television program) group, the amount of capitalized film and television production costs is amortized using a reasonably reliable estimate of the portion of unamortized film costs that is representative of the use of the film. Production costs are expensed as the film (or television program) is exhibited or exploited. Property, Plant and Equipment Property, plant and equipment is stated at cost, except for assets acquired using acquisition accounting, which are initially recorded at fair value (see Note 7). The cost of additions and substantial improvements to property, plant and equipment is capitalized, and includes internal compensation costs for these projects. The cost of maintenance and repairs of property, plant and equipment is charged to operating expenses. Property, plant and equipment costs are depreciated using straight-line methods over their estimated economic lives. Certain subsidiaries follow composite group depreciation methodology. Accordingly, when a portion of their depreciable property, plant and equipment is retired in the ordinary course of business, the gross book value is reclassified to accumulated depreciation, and no gain or loss is recognized on the disposition of these assets. Property, plant and equipment is reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. We recognize an impairment loss when the carrying amount of a long-lived asset is not recoverable. The carrying amount of a long-lived asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. See Note 7 for a discussion of asset abandonments. The liability for the fair value of an asset retirement obligation is recorded in the period in which it is incurred if a reasonable estimate of fair value can be made. In periods subsequent to initial measurement, we recognize period-to-period changes in the liability resulting from the passage of time and revisions to either the timing or the amount of the original estimate. The increase in the carrying value of the associated long-lived asset is depreciated over the corresponding estimated economic life. Software Costs We capitalize certain costs incurred in connection with developing or obtaining internal-use software. Capitalized software costs are included in “Property, Plant and Equipment” on our consolidated balance sheets. In addition, there is certain network software that allows the equipment to provide the features and functions unique to the AT&T network, which we include in the cost of the equipment categories for financial reporting purposes. We amortize our capitalized software costs over a three-year seven-year Goodwill and Other Intangible Assets We have the following major classes of intangible assets: goodwill; licenses, which include Federal Communications Commission (FCC) and other wireless licenses and orbital slots; distribution networks; film and television libraries; intellectual properties and franchises; trademarks and trade names; customer lists; and various other finite-lived intangible assets (see Note 9). Goodwill represents the excess of consideration paid over the fair value of identifiable net assets acquired in business combinations. Wireless licenses provide us with the exclusive right to utilize certain radio frequency spectrum to provide wireless communications services. While wireless licenses are issued for a fixed period of time (generally ten years), renewals of domestic wireless licenses have occurred routinely and at nominal cost. We have determined that there are currently no legal, regulatory, contractual, competitive, economic or other factors that limit the useful lives of our FCC wireless licenses. During the first quarter of 2019, in conjunction with the renewal process of certain wireless licenses in Mexico, we reassessed the estimated economic lives and renewal assumptions for these licenses. As a result, we have changed the life of these licenses from indefinite to finite-lived. On January 1, 2019, we began amortizing our wireless licenses in Mexico over their average remaining economic life of 25 years. This change in accounting does not materially impact our income statement. Orbital slots represent the space in which we operate the broadcast satellites that support our digital video entertainment service offerings. Similar to our FCC wireless licenses, there are limited legal and regulatory factors that constrain the useful lives of our orbital slots. We acquired the rights to the AT&T and other trade names in previous acquisitions, classifying certain of those trade names as indefinite-lived. We have the effective ability to retain these exclusive rights permanently at a nominal cost. Goodwill, FCC wireless licenses and other indefinite-lived intangible assets are not amortized but are tested at least annually for impairment. The testing is performed on the value as of October 1 each year, and compares the book values of the assets to their fair values. Goodwill is tested by comparing the carrying amount of each reporting unit, deemed to be our principal operating segments or one level below them, to the fair value using both discounted cash flow as well as market multiple approaches. FCC wireless licenses are tested on an aggregate basis, consistent with our use of the licenses on a national scope, using a discounted cash flow approach. Orbital slots are similarly aggregated for purposes of impairment testing and valued using a discounted cash flow approach. Trade names are tested by comparing their book values to their fair values calculated using a discounted cash flow approach on a presumed royalty rate derived from the revenues related to each brand name. Intangible assets that have finite useful lives are amortized over their estimated useful lives (see Note 9). Customer lists and relationships are amortized using primarily the sum-of-the-months-digits method of amortization over the period in which those relationships are expected to contribute to our future cash flows. Finite-lived trademarks and trade names and distribution networks are amortized using the straight-line method over the estimated useful life of the assets. Film library is amortized using the film forecast computation method, as previously disclosed. The remaining finite-lived intangible assets are generally amortized using the straight-line method. Advertising Costs We expense advertising costs for products and services or for promoting our corporate image as we incur them (see Note 22). Foreign Currency Translation Our foreign subsidiaries and foreign investments generally report their earnings in their local currencies. We translate their foreign assets and liabilities at exchange rates in effect at the balance sheet dates. We translate their revenues and expenses using average rates during the year. The resulting foreign currency translation adjustments are recorded as a separate component of accumulated OCI in our consolidated balance sheets (see Note 3). Operations in countries with highly inflationary economies consider the U.S. dollar as the functional currency. We hedge a portion of the foreign currency exchange risk involved in certain foreign currency-denominated transactions, which we explain further in our discussion of our methods of managing our foreign currency risk (see Note 13). Pension and Other Postretirement Benefits See Note 15 for a comprehensive discussion of our pension and postretirement benefit expense, including a discussion of the actuarial assumptions, our policy for recognizing the associated gains and losses and our method used to estimate service and interest cost components. New Accounting Standards Credit Loss Standard In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13, as amended), which replaces the incurred loss impairment methodology under current GAAP. ASU 2016-13 affects trade receivables, loans and other financial assets that are not subject to fair value through net income, as defined by the standard. The amendments under ASU 2016-13 will be effective as of January 1, 2020, and interim periods within that year. We do not expect the standard to have a material impact on our financial statements. Income Taxes In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (ASU 2019-12), which is expected to simplify income tax accounting requirements in areas deemed costly and complex. The amendments under ASU 2019-12 will be effective as of January 1, 2021, and interim periods within that year, with early adoption permitted in its entirety as of the beginning of the year of adoption. At adoption, the guidance allows for modified retrospective application through a cumulative effect adjustment to retained earnings. We are evaluating ASU 2019-12 for its impact to our financial statements.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share
Earnings Per Share [Text Block]	NOTE 2. EARNINGS PER SHARE A reconciliation of the numerators and denominators of basic and diluted earnings per share is shown in the table below: Year Ended December 31, 2019 2018 2017 Numerators Numerator for basic earnings per share: Net income $ 14,975 $ 19,953 $ 29,847 Less: Net income attributable to noncontrolling interest ( 1,072) ( 583) ( 397) Net income attributable to AT&T 13,903 19,370 29,450 Less: Preferred stock dividends ( 3) - - Net income attributable to common stock 13,900 19,370 29,450 Dilutive potential common shares: Share-based payment 21 19 13 Numerator for diluted earnings per share $ 13,921 $ 19,389 $ 29,463 Denominators (000,000) Denominator for basic earnings per share: Weighted-average number of common shares outstanding 7,319 6,778 6,164 Dilutive potential common shares: Share-based payment (in shares) 29 28 19 Denominator for diluted earnings per share 7,348 6,806 6,183 Basic earnings per share attributable to Common Stock $ 1.90 $ 2.85 $ 4.77 Diluted earnings per share attributable to Common Stock $ 1.89 $ 2.85 $ 4.76 We executed an accelerated share repurchase agreement with a third-party financial institution to repurchase AT&T common stock (see Note 17). Under the terms of the agreement, on January 3, 2020 , we paid the financial institution $4,000 and received approximately 80% of the stock, or 82.3 million shares. The final number of shares to be repurchased under the agreement will be based on the average of the daily volume-weighted average prices of AT&T common stock during the repurchase period, which is expected to conclude late in the first quarter of 2020. Upon final settlement of the agreement, we may be entitled to receive additional shares of AT&T common stock, or, under certain circumstances, we may be required to deliver shares of AT&T common stock or make a cash payment, at our election.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Income [Abstract]
Accumulated Other Comprehensive Income [Text Block]	NOTE 3. OTHER COMPREHENSIVE INCOME Changes in the balances of each component included in accumulated OCI are presented below. All amounts are net of tax and exclude noncontrolling interest. Foreign Currency Translation Adjustment Net Unrealized Gains (Losses) on Available-for-Sale Securities Net Unrealized Gains (Losses) on Cash Flow Hedges Defined Benefit Postretirement Plans Accumulated Other Comprehensive Income Balance as of December 31, 2016 $ ( 1,995) $ 541 $ 744 $ 5,671 $ 4,961 Other comprehensive income (loss) before reclassifications 20 187 371 1,083 1,661 Amounts reclassified from accumulated OCI - 1 ( 185) 1 39 2 ( 988) 3 ( 1,134) Net other comprehensive income (loss) 20 2 410 95 527 Amounts reclassified to retained earnings 4 ( 79) 117 248 1,243 1,529 Balance as of December 31, 2017 ( 2,054) 660 1,402 7,009 7,017 Other comprehensive income (loss) before reclassifications ( 1,030) ( 4) ( 597) 830 ( 801) Amounts reclassified from accumulated OCI - 1 - 1 13 2 ( 1,322) 3 ( 1,309) Net other comprehensive income (loss) ( 1,030) ( 4) ( 584) ( 492) ( 2,110) Amounts reclassified to retained earnings 5 - ( 658) - - ( 658) Balance as of December 31, 2018 ( 3,084) ( 2) 818 6,517 4,249 Other comprehensive income (loss) before reclassifications 28 50 ( 900) 3,457 2,635 Amounts reclassified from accumulated OCI - 1 - 1 45 2 ( 1,459) 3 ( 1,414) Net other comprehensive income (loss) 28 50 ( 855) 1,998 1,221 Balance as of December 31, 2019 $ ( 3,056) $ 48 $ ( 37) $ 8,515 $ 5,470 1 (Gains) losses are included in Other income (expense) - net in the consolidated statements of income. 2 (Gains) losses are included in Interest expense in the consolidated statements of income (see Note 13). 3 The amortization of prior service credits associated with postretirement benefits is included in Other income (expense) in the consolidated statements of income (see Note 15). 4 With the adoption of ASU 2018-02, the stranded tax effects resulting from the application of the Tax Cuts and Jobs Act are reclassified to retained earnings (see Note 1). 5 With the adoption of ASU 2016-01, the unrealized (gains) losses on our equity investments are reclassified to retained earnings (see Note 1).

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Information
Segment Information [Text Block]	NOTE 4. SEGMENT INFORMATION Our segments are strategic business units that offer products and services to different customer segments over various technology platforms and/or in different geographies that are managed accordingly. We analyze our segments based on segment operating contribution, which consists of operating income, excluding acquisition-related costs and other significant items (as discussed below), and equity in net income (loss) of affiliates for investments managed within each segment. We have four reportable segments: (1) Communications, (2) WarnerMedia, (3) Latin America, and (4) Xandr. We also evaluate segment and business unit performance based on EBITDA and/or EBITDA margin. EBITDA is defined as operating contribution excluding equity in net income (loss) of affiliates and depreciation and amortization. We believe EBITDA to be a relevant and useful measurement to our investors as it is part of our internal management reporting and planning processes and it is an important metric that management uses to evaluate operating performance. EBITDA does not give effect to cash used for debt service requirements and thus does not reflect available funds for distributions, reinvestment or other discretionary uses. EBITDA margin is EBITDA divided by total revenues. We have recast our segment results for all prior periods to exclude wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands from our Mobility and Business Wireline business units of the Communications segment, instead reporting them with Corporate and Other (see Note 6). The Communications segment provides wireless and wireline telecom, video and broadband services to consumers located in the U.S. and businesses globally. This segment contains the following business units:  Mobility provides nationwide wireless service and equipment.  Entertainment Group provides video, including OTT services, broadband and voice communications services primarily to residential customers. This segment also sells advertising on DIRECTV and U-verse distribution platforms.  Business Wireline provides advanced IP-based services, as well as traditional voice and data services to business customers. The WarnerMedia segment develops, produces and distributes feature films, television, gaming and other content in various physical and digital formats globally. This segment contains the following business units:  Turner primarily operates multichannel basic television networks and digital properties. Turner also sells advertising on its networks and digital properties.  Home Box Office consists of premium pay television and OTT and streaming services domestically and premium pay, basic tier television and OTT and streaming services internationally, as well as content licensing and home entertainment.  Warner Bros. consists of the production, distribution and licensing of television programming and feature films, the distribution of home entertainment products and the production and distribution of games. The Latin America segment provides entertainment and wireless services outside of the U.S. This segment contains the following business units:  Mexico provides wireless service and equipment to customers in Mexico.  Vrio provides video services primarily to residential customers using satellite technology in Latin America and the Caribbean. The Xandr segment provides advertising services. These services utilize data insights to develop higher-value targeted advertising across video and digital platforms. Certain revenues in this segment are also reported by the Communications segment and are eliminated upon consolidation. Corporate and Other reconciles our segment results to consolidated operating income and income before income taxes, and includes:  Corporate , which consists of: (1) businesses no longer integral to our operations or which we no longer actively market, (2) corporate support functions, (3) impacts of corporate-wide decisions for which the individual operating segments are not being evaluated, (4) the reclassification of the amortization of prior service credits, which we continue to report with segment operating expenses, to consolidated other income (expense) – net and (5) the recharacterization of programming intangible asset amortization, for released programming acquired in the Time Warner acquisition, which we continue to report within WarnerMedia segment operating expense, to consolidated amortization expense. The programming and intangible asset amortization reclass was $ 472 and $ 1,416 for the year ended December 31, 2019 and 2018, respectively.  Acquisition-related items which consists of items associated with the merger and integration of acquired businesses, including amortization of intangible assets.  Certain significant items includes (1) employee separation charges associated with voluntary and/or strategic offers, (2) losses resulting from abandonment or impairment of assets and (3) other items for which the segments are not being evaluated.  Eliminations and consolidations , which (1) removes transactions involving dealings between our segments, including content licensing between WarnerMedia and Communications, and (2) includes adjustments for our reporting of the advertising business. Interest expense and other income (expense) – net, are managed only on a total company basis and are, accordingly, reflected only in consolidated results. For the year ended December 31, 2019 Revenues Operations and Support Expenses EBITDA Depreciation and Amortization Operating Income (Loss) Equity in Net Income (Loss) of Affiliates Segment Contribution Communications Mobility $ 71,056 $ 40,681 $ 30,375 $ 8,054 $ 22,321 $ - $ 22,321 Entertainment Group 45,126 35,028 10,098 5,276 4,822 - 4,822 Business Wireline 26,177 16,091 10,086 4,999 5,087 - 5,087 Total Communications 142,359 91,800 50,559 18,329 32,230 - 32,230 WarnerMedia Turner 13,122 7,740 5,382 235 5,147 52 5,199 Home Box Office 6,749 4,312 2,437 102 2,335 30 2,365 Warner Bros. 14,358 11,816 2,542 162 2,380 ( 30) 2,350 Other ( 730) ( 71) ( 659) 39 ( 698) 110 ( 588) Total WarnerMedia 33,499 23,797 9,702 538 9,164 162 9,326 Latin America Vrio 4,094 3,378 716 660 56 27 83 Mexico 2,869 3,085 ( 216) 502 ( 718) - ( 718) Total Latin America 6,963 6,463 500 1,162 ( 662) 27 ( 635) Xandr 2,022 646 1,376 58 1,318 - 1,318 Segment Total 184,843 122,706 62,137 20,087 42,050 $ 189 $ 42,239 Corporate and Other Corporate 1,675 3,008 ( 1,333) 629 ( 1,962) Acquisition-related items ( 72) 960 ( 1,032) 7,460 ( 8,492) Certain significant items - 2,082 ( 2,082) 43 ( 2,125) Eliminations and consolidations ( 5,253) ( 3,735) ( 1,518) ( 2) ( 1,516) AT&T Inc. $ 181,193 $ 125,021 $ 56,172 $ 28,217 $ 27,955 For the year ended December 31, 2018 Revenues Operations and Support Expenses EBITDA Depreciation and Amortization Operating Income (Loss) Equity in Net Income (Loss) of Affiliates Segment Contribution Communications Mobility $ 70,521 $ 40,690 $ 29,831 $ 8,263 $ 21,568 $ - $ 21,568 Entertainment Group 46,460 36,430 10,030 5,315 4,715 - 4,715 Business Wireline 26,740 16,201 10,539 4,714 5,825 - 5,825 Total Communications 143,721 93,321 50,400 18,292 32,108 - 32,108 WarnerMedia Turner 6,979 3,794 3,185 131 3,054 54 3,108 Home Box Office 3,598 2,187 1,411 56 1,355 29 1,384 Warner Bros. 8,703 7,130 1,573 96 1,477 ( 28) 1,449 Other ( 339) ( 145) ( 194) 22 ( 216) ( 30) ( 246) Total WarnerMedia 18,941 12,966 5,975 305 5,670 25 5,695 Latin America Vrio 4,784 3,743 1,041 728 313 34 347 Mexico 2,868 3,415 ( 547) 510 ( 1,057) - ( 1,057) Total Latin America 7,652 7,158 494 1,238 ( 744) 34 ( 710) Xandr 1,740 398 1,342 9 1,333 - 1,333 Segment Total 172,054 113,843 58,211 19,844 38,367 $ 59 $ 38,426 Corporate and Other Corporate 2,150 2,250 ( 100) 1,630 ( 1,730) Acquisition-related items ( 49) 1,185 ( 1,234) 6,931 ( 8,165) Certain significant items - 899 ( 899) 26 ( 925) Eliminations and consolidations ( 3,399) ( 1,947) ( 1,452) ( 1) ( 1,451) AT&T Inc. $ 170,756 $ 116,230 $ 54,526 $ 28,430 $ 26,096 For the year ended December 31, 2017 Revenues Operations and Support Expenses EBITDA Depreciation and Amortization Operating Income (Loss) Equity in Net Income (Loss) of Affiliates Segment Contribution Communications Mobility $ 70,259 $ 42,317 $ 27,942 $ 7,931 $ 20,011 $ - $ 20,011 Entertainment Group 49,995 38,903 11,092 5,621 5,471 - 5,471 Business Wireline 29,203 18,441 10,762 4,756 6,006 - 6,006 Total Communications 149,457 99,661 49,796 18,308 31,488 - 31,488 WarnerMedia Turner 430 331 99 4 95 45 140 Home Box Office - - - - - - - Warner Bros. - - - - - - - Other - 4 ( 4) - ( 4) ( 74) ( 78) Total WarnerMedia 430 335 95 4 91 ( 29) 62 Latin America Vrio 5,456 4,172 1,284 849 435 87 522 Mexico 2,813 3,232 ( 419) 369 ( 788) - ( 788) Total Latin America 8,269 7,404 865 1,218 ( 353) 87 ( 266) Xandr 1,373 169 1,204 2 1,202 - 1,202 Segment Total 159,529 107,569 51,960 19,532 32,428 $ 58 $ 32,486 Corporate and Other Corporate 2,443 3,911 ( 1,468) 214 ( 1,682) Acquisition-related items - 798 ( 798) 4,608 ( 5,406) Certain significant items ( 243) 3,880 ( 4,123) 33 ( 4,156) Eliminations and consolidations ( 1,183) 31 ( 1,214) - ( 1,214) AT&T Inc. $ 160,546 $ 116,189 $ 44,357 $ 24,387 $ 19,970 The following table is a reconciliation of operating income (loss) to Income Before Income Taxes reported in our consolidated statements of income: 2019 2018 2017 Communications $ 32,230 $ 32,108 $ 31,488 WarnerMedia 9,326 5,695 62 Latin America ( 635) ( 710) ( 266) Xandr 1,318 1,333 1,202 Segment Contribution 42,239 38,426 32,486 Reconciling Items: Corporate and Other ( 1,962) ( 1,730) ( 1,682) Merger and integration items ( 1,032) ( 1,234) ( 798) Amortization of intangibles acquired ( 7,460) ( 6,931) ( 4,608) Abandonments and impairments ( 1,458) ( 46) ( 2,914) Employee separation charges ( 624) ( 587) ( 445) Other noncash charges (credits), net ( 43) ( 111) 49 Natural disaster items - ( 181) ( 626) Tax reform special bonus - - ( 220) Segment equity in net income of affiliates ( 189) ( 59) ( 58) Eliminations and consolidations ( 1,516) ( 1,451) ( 1,214) AT&T Operating Income 27,955 26,096 19,970 Interest Expense 8,422 7,957 6,300 Equity in net income (loss) of affiliates 6 ( 48) ( 128) Other income (expense) - net ( 1,071) 6,782 1,597 Income Before Income Taxes $ 18,468 $ 24,873 $ 15,139 The following table sets forth revenues earned from customers, and property, plant and equipment located in different geographic areas. 2019 2018 2017 Revenues Net Property, Plant & Equipment Revenues Net Property, Plant & Equipment Revenues Net Property, Plant & Equipment United States $ 162,344 $ 122,567 $ 154,795 $ 123,457 $ 149,841 $ 118,200 Europe 6,137 1,854 4,073 1,634 1,064 392 Mexico 3,198 3,648 3,100 3,467 2,913 3,619 Brazil 2,761 1,057 2,724 1,213 2,948 1,447 All other Latin America 3,219 544 3,055 1,217 2,743 1,294 Asia/Pacific Rim 2,651 390 2,214 408 829 194 Other 883 68 795 77 208 76 Total $ 181,193 $ 130,128 $ 170,756 $ 131,473 $ 160,546 $ 125,222 The following tables present intersegment revenues, assets, investments in equity affiliates and capital expenditures by segment. Intersegment Reconciliation 2019 2018 2017 Intersegment revenues Communications $ 26 $ 13 $ - WarnerMedia 3,308 1,875 134 Latin America - - - Xandr 10 - - Total Intersegment Revenues 3,344 1,888 134 Consolidations 1,909 1,511 1,049 Eliminations and consolidations $ 5,253 $ 3,399 $ 1,183 At or for the years ended December 31, 2019 2018 Investments in Equity Method Investees Capital Expenditures Investments in Equity Method Investees Capital Expenditures Assets Assets Communications $ 521,252 $ - $ 17,410 $ 485,357 $ - $ 19,509 WarnerMedia 137,264 3,011 1,013 132,453 5,547 581 Latin America 20,606 650 757 18,148 677 745 Xandr 3,116 - 192 2,718 - 106 Corporate and eliminations ( 130,569) 34 263 ( 106,812) 21 310 Total $ 551,669 $ 3,695 $ 19,635 $ 531,864 $ 6,245 $ 21,251

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	NOTE 5. REVENUE RECOGNITION We report our revenues net of sales taxes and record certain regulatory fees, primarily Universal Service Fund (USF) fees, on a net basis. Wireless, Advanced Data, Legacy Voice & Data Services and Equipment Revenue We offer service-only contracts and contracts that bundle equipment used to access the services and/or with other service offerings. Some contracts have fixed terms and others are cancellable on a short-term basis (i.e., month-to-month arrangements). Examples of service revenues include wireless, video entertainment (e.g., AT&T U-verse and DIRECTV), strategic services (e.g., virtual private network service), and legacy voice and data (e.g., traditional local and long-distance). These services represent a series of distinct services that is considered a separate performance obligation. Service revenue is recognized when services are provided, based upon either usage (e.g., minutes of traffic/bytes of data processed) or period of time (e.g., monthly service fees). Some of our services require customer premises equipment that, when combined and integrated with AT&T’s specific network infrastructure, facilitate the delivery of service to the customer. In evaluating whether the equipment is a separate performance obligation, we consider the customer’s ability to benefit from the equipment on its own or together with other readily available resources and if so, whether the service and equipment are separately identifiable (i.e., is the service highly dependent on, or highly interrelated with the equipment). When the equipment does not meet the criteria to be a distinct performance obligation (e.g., equipment associated with certain video services), we allocate the total transaction price to the related service. When equipment is a distinct performance obligation, we record the sale of equipment when title has passed and the products are accepted by the customer. For devices sold through indirect channels (e.g., national dealers), revenue is recognized when the dealer accepts the device, not upon activation. Our equipment and service revenues are predominantly recognized on a gross basis, as most of our services do not involve a third party and we typically control the equipment that is sold to our customers. Revenue recognized from fixed term contracts that bundle services and/or equipment is allocated based on the stand-alone selling price of all required performance obligations of the contract (i.e., each item included in the bundle). Promotional discounts are attributed to each required component of the arrangement, resulting in recognition over the contract term. Stand-alone selling prices are determined by assessing prices paid for service-only contracts (e.g., arrangements where customers bring their own devices) and stand-alone device pricing. We offer the majority of our customers the option to purchase certain wireless devices in installments over a specified period of time, and, in many cases, they may be eligible to trade in the original equipment for a new device and have the remaining unpaid balance paid or settled. For customers that elect these equipment installment payment programs, at the point of sale, we recognize revenue for the entire amount of revenue allocated to the customer receivable net of fair value of the trade-in right guarantee. The difference between the revenue recognized and the consideration received is recorded as a note receivable when the devices are not discounted and our right to consideration is unconditional. When installment sales include promotional discounts (e.g., “buy one get one free”), the difference between revenue recognized and consideration received is recorded as a contract asset to be amortized over the contract term. Less commonly, we offer certain customers highly discounted devices when they enter into a minimum service agreement term. For these contracts, we recognize equipment revenue at the point of sale based on a stand-alone selling price allocation. The difference between the revenue recognized and the cash received is recorded as a contract asset that will amortize over the contract term. Our contracts allow for customers to frequently modify their arrangement, without incurring penalties in many cases. When a contract is modified, we evaluate the change in scope or price of the contract to determine if the modification should be treated as a new contract or if it should be considered a change of the existing contract. We generally do not have significant impacts from contract modifications. Revenues from transactions between us and our customers are recorded net of revenue-based regulatory fees and taxes. Cash incentives given to customers are recorded as a reduction of revenue. Nonrefundable, upfront service activation and setup fees associated with service arrangements are deferred and recognized over the associated service contract period or customer life. Subscription Revenue Subscription revenues from cable networks and premium pay and basic-tier television services are recognized over the license period as programming is provided to affiliates or digital distributors based on negotiated contractual programming rates. When a distribution contract with an affiliate has expired and a new distribution contract has not been executed, revenues are based on estimated rates, giving consideration to factors including the previous contractual rates, inflation, current payments by the affiliate and the status of the negotiations on a new contract. When the new distribution contract terms are finalized, an adjustment to revenue is recorded, if necessary, to reflect the new terms. Subscription revenues from end-user subscribers are recognized when services are provided, based upon either usage or period of time. Subscription revenues from streaming services are recognized as programming services are provided to customers. Content Revenue Feature films typically are produced or acquired for initial exhibition in theaters, followed by distribution, generally commencing within three years of such initial exhibition. Revenues from film rentals by theaters are recognized as the films are exhibited. Television programs and series are initially produced for broadcast and may be subsequently licensed or sold in physical format and/or electronic delivery. Revenues from the distribution of television programming through broadcast networks, cable networks, first-run syndication and streaming services are recognized when the programs or series are available to the licensee. In certain circumstances, pursuant to the terms of the applicable contractual arrangements, the availability dates granted to customers may precede the date in which the customer can be billed for these sales. Revenues from sales of feature films and television programming in physical format are recognized at the later of the delivery date or the date when made widely available for sale or rental by retailers based on gross sales less a provision for estimated returns, rebates and pricing allowances. Revenues from the licensing of television programs and series for electronic sell-through or video-on-demand are recognized when the product has been purchased by and made available to the consumer to either download or stream. Upfront or guaranteed payments for the licensing of intellectual property are recognized as revenue at either the inception of the license term if the intellectual property has significant standalone functionality or over the corresponding license term if the licensee’s ability to derive utility is dependent on our continued support of the intellectual property throughout the license term. Revenues from the sales of console games are recognized at the later of the delivery date or the date that the product is made widely available for sale or rental by retailers based on gross sales less a provision for estimated returns, rebates and pricing allowances. Advertising Revenue Advertising revenues are recognized, net of agency commissions, in the period that the advertisements are aired. If there is a targeted audience guarantee, revenues are recognized for the actual audience delivery and revenues are deferred for any shortfall until the guaranteed audience delivery is met, typically by providing additional advertisements. Advertising revenues from digital properties are recognized as impressions are delivered or the services are performed. Revenue Categories The following tables set forth reported revenue by category and by business unit: For the year ended December 31, 2019 Service Revenues Wireless Advanced Data Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 55,040 $ - $ - $ - $ - $ 291 $ - $ 15,725 $ 71,056 Entertainment Group - 8,403 2,573 30,438 - 1,672 2,032 8 45,126 Business Wireline - 12,926 9,180 - - - 3,286 785 26,177 WarnerMedia Turner - - - 7,736 481 4,566 339 - 13,122 Home Box Office - - - 5,814 925 - 10 - 6,749 Warner Bros. - - - 88 13,532 41 697 - 14,358 Eliminations and Other - - - 222 ( 1,058) 69 37 - ( 730) Latin America Vrio - - - 4,094 - - - - 4,094 Mexico 1,863 - - - - - - 1,006 2,869 Xandr - - - - - 2,022 - - 2,022 Corporate and Other 549 51 155 - - - 678 170 1,603 Eliminations and consolidations - - - - ( 3,249) ( 1,672) ( 332) - ( 5,253) Total Operating Revenues $ 57,452 $ 21,380 $ 11,908 $ 48,392 $ 10,631 $ 6,989 $ 6,747 $ 17,694 $ 181,193 For the year ended December 31, 2018 Service Revenues Wireless Advanced Data Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 54,062 $ - $ - $ - $ - $ 232 $ - $ 16,227 $ 70,521 Entertainment Group - 7,956 3,041 31,762 - 1,595 2,097 9 46,460 Business Wireline - 12,245 10,674 - - - 2,998 823 26,740 WarnerMedia Turner - - - 4,207 295 2,330 147 - 6,979 Home Box Office - - - 3,201 391 - 6 - 3,598 Warner Bros. - - - 47 8,216 53 387 - 8,703 Eliminations and Other - - - 74 ( 518) 78 27 - ( 339) Latin America Vrio - - - 4,784 - - - - 4,784 Mexico 1,701 - - - - - - 1,167 2,868 Xandr - - - - - 1,740 - - 1,740 Corporate and Other 638 52 36 - - - 1,190 185 2,101 Eliminations and consolidations - - - - ( 1,843) ( 1,595) 39 - ( 3,399) Total Operating Revenues $ 56,401 $ 20,253 $ 13,751 $ 44,075 $ 6,541 $ 4,433 $ 6,891 $ 18,411 $ 170,756 No customer accounted for more than 10% of consolidated revenues in 2019, 2018 or 2017. Deferred Customer Contract Acquisition and Fulfillment Costs Costs to acquire and fulfill customer contracts, including commissions on service activations, for our wireless, business wireline and video entertainment services, are deferred and amortized over the contract period or expected customer relationship life, which typically ranges from three years to five years. For contracts with an estimated amortization period of less than one year, we expense incremental costs immediately. The following table presents the deferred customer contract acquisition and fulfillment costs included on our consolidated balance sheets at December 31: Consolidated Balance Sheets 2019 2018 Deferred Acquisition Costs Other current assets $ 2,462 $ 1,901 Other Assets 2,991 2,073 Total deferred customer contract acquisition costs $ 5,453 $ 3,974 Deferred Fulfillment Costs Other current assets $ 4,519 $ 4,090 Other Assets 6,439 7,450 Total deferred customer contract fulfillment costs $ 10,958 $ 11,540 The following table presents amortization of deferred customer contract acquisition and fulfillment cost, which are recorded in other cost of revenues in our consolidated statements of income, for the year ended December 31: Consolidated Statements of Income 2019 2018 Deferred acquisition cost amortization $ 2,174 $ 1,433 Deferred fulfillment cost amortization 4,947 4,039 Contract Assets and Liabilities A contract asset is recorded when revenue is recognized in advance of our right to bill and receive consideration. The contract asset will decrease as services are provided and billed. For example, when installment sales include promotional discounts (e.g., “buy one get one free”) the difference between revenue recognized and consideration received is recorded as a contract asset to be amortized over the contract term. When consideration is received in advance of the delivery of goods or services, a contract liability is recorded for deferred revenue. Reductions in the contract liability will be recorded as revenue as we satisfy the performance obligations. The following table presents contract assets and liabilities on our consolidated balance sheets at December 31: Consolidated Balance Sheets 2019 2018 Contract assets $ 2,472 $ 1,896 Contract liabilities 6,999 6,856 Our beginning of period contract liabilities recorded as customer contract revenue during 2019 was $ 5,394. Our consolidated balance sheets at December 31, 2019 and 2018 included approximately $ 1,611 and $ 1,244, respectively, for the current portion of our contract assets in “Other current assets” and $ 5,939 and $ 5,752, respectively, for the current portion of our contract liabilities in “Advanced billings and customer deposits.” Remaining Performance Obligations Remaining performance obligations represent services we are required to provide to customers under bundled or discounted arrangements, which are satisfied as services are provided over the contract term. In determining the transaction price allocated, we do not include nonrecurring charges and estimates for usage, nor do we consider arrangements with an original expected duration of less than one year, which are primarily prepaid wireless, video and residential internet agreements. Remaining performance obligations associated with business contracts reflect recurring charges billed, adjusted to reflect estimates for sales incentives and revenue adjustments. Performance obligations associated with wireless contracts are estimated using a portfolio approach in which we review all relevant promotional activities, calculating the remaining performance obligation using the average service component for the portfolio and the average device price. As of December 31, 2019, the aggregate amount of the transaction price allocated to remaining performance obligations was $ 39,245, of which we expect to recognize approximately 60% by the end of 2020, with the balance recognized thereafter. 2017 Results Prior to the adoption of ASC 606 in 2018, revenue recognized from contracts that bundle services and equipment was limited to the lesser of the amount allocated based on the relative selling price of the equipment and service already delivered or the consideration received from the customer for the equipment and service already delivered. Our prior accounting also separately recognized regulatory fees as operating revenue when received and as an expense when incurred. Sales commissions were previously expensed as incurred.

Acquisitions, Dispositions And

Acquisitions, Dispositions And Other Adjustments	12 Months Ended
	Dec. 31, 2019
Acquisitions, Dispositions And Other Adjustments
Acquisitions, Dispositions And Other Adjustments [Text Block]	NOTE 6. ACQUISITIONS, DISPOSITIONS AND OTHER ADJUSTMENTS Acquisitions Time Warner On June 14, 2018, we completed our acquisition of Time Warner, a leader in media and entertainment whose major businesses encompass an array of some of the most respected media brands. We paid Time Warner shareholders $ 36,599 in AT&T stock and $ 42,100 in cash. Total consideration, including share-based payment arrangements and other adjustments, totaled $ 79,358, excluding Time Warner’s net debt at acquisition. The fair values of the assets acquired and liabilities assumed were determined using the income, cost and market approaches. The fair value measurements were primarily based on significant inputs that are not observable in the market and thus represent a Level 3 measurement as defined in ASC 820, “Fair Value Measurement,” other than cash and long-term debt acquired in the acquisition. The income approach was primarily used to value the intangible assets, consisting primarily of distribution network, released TV and film content, in-place advertising network, trade names, and franchises. The income approach estimates fair value for an asset based on the present value of cash flow projected to be generated by the asset. Projected cash flow is discounted at a required rate of return that reflects the relative risk of achieving the cash flow and the time value of money. The cost approach, which estimates value by determining the current cost of replacing an asset with another of equivalent economic utility, was used, as appropriate, for plant, property and equipment. The cost to replace a given asset reflects the estimated reproduction or replacement cost for the property, less an allowance for loss in value due to depreciation. Goodwill is calculated as the difference between the acquisition date fair value of the consideration transferred and the fair value of the net assets acquired, and represents the future economic benefits that we expect to achieve as a result of the acquisition. The following table summarizes the fair values of the Time Warner assets acquired and liabilities assumed and related deferred income taxes as of the acquisition date: Assets acquired Cash $ 1,889 Accounts receivable 9,020 All other current assets 2,913 Noncurrent inventory and theatrical film and television production costs 5,591 Property, plant and equipment 4,693 Intangible assets subject to amortization Distribution network 18,040 Released television and film content 10,806 Trademarks and trade names 18,081 Other 10,300 Investments and other assets 9,438 Goodwill 38,801 Total assets acquired 129,572 Liabilities assumed Current liabilities, excluding current portion of long-term debt 8,294 Debt maturing within one year 4,471 Long-term debt 18,394 Other noncurrent liabilities 19,054 Total liabilities assumed 50,213 Net assets acquired 79,359 Noncontrolling interest ( 1) Aggregate value of consideration paid $ 79,358 For the 200-day period ended December 31, 2018, our consolidated statement of income included $ 18,209 of revenues and $ 1,400 of operating income, which included $ 3,296 of intangible amortization, from Time Warner and its affiliates. The following unaudited pro forma consolidated results of operations assume that the acquisition of Time Warner was completed as of January 1, 2017. (Unaudited) Year Ended December 31, 2018 2017 Total operating revenues $ 183,651 $ 188,769 Net Income Attributable to AT&T 20,814 31,380 Basic Earnings Per Share Attributable to Common Stock $ 2.86 $ 4.30 Diluted Earnings Per Share Attributable to Common Stock $ 2.85 $ 4.26 These unaudited pro forma consolidated results reflect the adoption of ASC 606 for 2018, which is not on a comparable basis with 2017 (see Note 5). Pro forma data may not be indicative of the results that would have been obtained had these events occurred at the beginning of the periods presented, nor is it intended to be a projection of future results. Otter Media On August 7, 2018, we acquired the remaining interest in Otter Media Holdings (Otter Media) for $ 157 in cash and the conversion to equity of the $ 1,480 advance made in the first quarter of 2018. At acquisition, we remeasured the fair value of the total business, which exceeded the carrying amount of our equity method investment and resulted in a pre-tax gain of $ 395. We consolidated that business upon close and recorded those assets at fair value, including $ 1,239 of goodwill that is reported in the WarnerMedia segment. AppNexus On August 15, 2018, we purchased AppNexus for $ 1,432 and recorded $ 1,220 of goodwill that is reported in the Xandr segment. Our investment will allow us to create a marketplace for TV and digital video advertising. Spectrum Auctions In December 2019 982 of 24 GHz spectrum in an FCC auction. In April 2017 910 of spectrum in 18 markets. We provided the FCC an initial deposit of $ 2,348 in July 2016 and received a refund of $ 1,438 in April 2017, which was recorded as cash from investing activities in our consolidated statement of cash flows. In 2018 Dispositions Hudson Yards In June 2019 2,081 and recorded a loss of approximately $ 100 resulting from transaction costs (primarily real estate transfer taxes). Hulu In April 2019 1,430 and recorded a gain of $ 740. Data Colocation Operations On December 31, 2018, we sold certain data centers to Brookfield Infrastructure Partners for $ 1,100 and recorded a pre-tax gain of $ 432. The sale included assets; primarily consisting of property, plant and equipment, of $ 298; and goodwill of $ 215. Held-for-Sale In October 2019 1,950. We expect the transaction to close in the first half of 2020, subject to customary closing conditions. We applied held-for-sale treatment to the assets and liabilities of these operations, and, accordingly, included the assets in “Other current assets,” and the related liabilities in “Accounts payable and accrued liabilities,” on our consolidated balance sheet at December 31, 2019. The assets and liabilities primarily consist of approximately $ 700 of net property, plant and equipment; $ 1,100 of FCC licenses; $ 300 of goodwill; and $ 400 of net tax liabilities.

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2019
Property, Plant And Equipment
Property, Plant And Equipment [Text Block]	NOTE 7. PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment is summarized as follows at December 31: Lives (years) 2019 2018 Land - $ 2,651 $ 2,714 Buildings and improvements 2-44 38,924 38,013 Central office equipment 1 3-10 96,061 95,173 Cable, wiring and conduit 15-50 72,042 73,397 Satellites 14-17 2,489 2,961 Other equipment 3-20 94,951 93,782 Software 3-7 22,244 19,124 Under construction - 4,176 5,526 333,538 330,690 Accumulated depreciation and amortization 203,410 199,217 Property, plant and equipment - net $ 130,128 $ 131,473 1 Includes certain network software. Our depreciation expense was $ 20,285 in 2019, $ 20,083 in 2018 and $ 19,761 in 2017. Depreciation expense included amortization of software totaling $ 3,313 in 2019, $ 3,092 in 2018 and $ 2,810 in 2017. In 2017, as a result of planned fiber deployment, we recorded a noncash pre-tax charge of $ 2,883 to abandon certain copper assets that we did not plan to utilize to support network activity. Largely due to the pace at which our customers have migrated to fiber, which exceeded previous forecasts, we identified additional copper assets that we no longer expect will be utilized to support future network activity. In the fourth quarter of 2019, we recorded a noncash pre-tax charge of $ 1,290 to abandon these copper assets. Each of these abandonments is considered outside the ordinary course of business.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	NOTE 8. LEASES We have operating and finance leases for certain facilities and equipment used in our operations. As of December 31, 2019, our leases have remaining lease terms of up to 15 some of our leases include options to terminate the leases within one year Upon the adoption of ASC 842 on January 1, 2019, we recognized a right-of-use asset for operating leases, and an operating lease liability that represents the present value of our obligation to make payments over the lease terms. The present value of the lease payments is calculated using the incremental borrowing rate for operating and finance leases, which is determined using a portfolio approach based on the rate of interest that we would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term. We use the unsecured borrowing rate and risk-adjust that rate to approximate a collateralized rate in the currency of the lease, which is updated on a quarterly basis for measurement of new lease obligations. The components of lease expense are as follows: 2019 Operating lease cost $ 5,684 Finance lease cost: Amortization of right-of-use assets $ 271 Interest on lease obligation 169 Total finance lease cost $ 440 The following tables set forth supplemental balance sheet information related to leases at December 31, 2019: Operating Leases Operating lease right-of-use assets $ 24,039 Accounts payable and accrued liabilities $ 3,451 Operating lease obligation 21,804 Total operating lease obligation $ 25,255 Finance Leases Property, plant and equipment, at cost $ 3,534 Accumulated depreciation and amortization ( 1,296) Property, plant and equipment, net $ 2,238 Current portion of long-term debt $ 162 Long-term debt 1,872 Total finance lease obligation $ 2,034 Weighted-Average Remaining Lease Term Operating leases 8.4 yrs Finance leases 10.3 yrs Weighted-Average Discount Rate Operating leases 4.2 % Finance leases 8.4 % The following table provides the expected future minimum maturities of lease obligations: Operating Finance Leases Leases 2020 $ 4,723 $ 340 2021 4,349 305 2022 4,028 289 2023 3,611 274 2024 3,078 258 Thereafter 11,366 1,649 Total lease payments 31,155 3,115 Less: imputed interest ( 5,900) ( 1,081) Total $ 25,255 $ 2,034

Goodwill And Other Intangible A

Goodwill And Other Intangible Assets	12 Months Ended
	Dec. 31, 2019
Goodwill And Other Intangible Assets
Goodwill And Other Intangible Assets [Text Block]	NOTE 9. GOODWILL AND OTHER INTANGIBLE ASSETS The following table sets forth the changes in the carrying amounts of goodwill by operating segment. We test goodwill for impairment at a reporting unit level, which is deemed to be our principal operating segments or one level below. Our Communications segment has three reporting units: Mobility, Entertainment Group and Business Wireline. Our WarnerMedia segment has three reporting units: Turner, Home Box Office and Warner Bros. Our Latin America segment has two reporting units: Mexico and Vrio. 2019 2018 Balance at Jan. 1 Acquisitions Dispositions, currency exchange and other Balance at Dec. 31 Balance at Jan. 1 Reallocation Acquisitions Dispositions, currency exchange and other Balance at Dec. 31 Communications $ 100,551 $ - $ ( 317) $ 100,234 $ 39,280 $ 61,075 $ 422 $ ( 226) $ 100,551 WarnerMedia 40,698 - 181 40,879 - 681 40,036 ( 19) 40,698 Latin America 3,718 - ( 56) 3,662 4,234 ( 32) - ( 484) 3,718 Xandr 1,403 66 ( 3) 1,466 - 211 1,220 ( 28) 1,403 Business Solutions - - - - 45,395 ( 45,395) - - - Consumer Mobility - - - - 16,540 ( 16,540) - - - Total $ 146,370 $ 66 $ ( 195) $ 146,241 $ 105,449 $ - $ 41,678 $ ( 757) $ 146,370 Changes to our goodwill in 2019, primarily resulted from the held-for-sale treatment of wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands (see Note 6) and final valuations related to our acquisitions of Time Warner and Otter Media, as well as changes from foreign currency translation. The majority of our goodwill acquired in 2018 is from our acquisitions of Time Warner, AppNexus and Otter Media. Other changes to our goodwill in 2018 include the sale of our data colocation operations, as well as changes from foreign currency translation. With our segment realignment in 2018, we reallocated goodwill within our reporting units. Our other intangible assets at December 31 are summarized as follows: 2019 2018 Other Intangible Assets Weighted-Average Life Gross Carrying Amount Accumulated Amortization Currency Translation Adjustment Gross Carrying Amount Accumulated Amortization Currency Translation Adjustment Amortized intangible assets: Wireless licenses 24.5 years $ 2,981 $ 156 $ ( 243) $ - $ - $ - Trademarks and trade names 37.3 years 18,359 853 ( 6) 18,371 293 ( 7) Distribution network 10.0 years 18,138 2,793 - 18,040 971 - Released television and film content 16.4 years 10,941 4,974 - 10,814 2,988 - Customer lists and relationships 9.1 years 20,304 14,773 ( 281) 20,516 12,451 ( 314) Other 20.4 years 11,427 1,843 ( 3) 11,624 907 ( 25) Total 21.5 years $ 82,150 $ 25,392 $ ( 533) $ 79,365 $ 17,610 $ ( 346) Indefinite-lived intangible assets not subject to amortization, net of currency translation adjustment: Licenses: Wireless licenses $ 83,623 $ 84,442 Orbital slots 11,702 11,702 Trade names 6,067 6,274 Total $ 101,392 $ 102,418 Amortized intangible assets are definite-life assets, and, as such, we record amortization expense based on a method that most appropriately reflects our expected cash flows from these assets. Amortization expense for definite-life intangible assets was $ 7,932 for the year ended December 31, 2019, $ 8,347 for the year ended December 31, 2018 and $ 4,626 for the year ended December 31, 2017. Amortization expense is estimated to be $ 6,614 in 2020, $ 5,683 in 2021, $ 4,961 in 2022, $ 4,299 in 2023 and $ 3,644 in 2024. We review amortized intangible assets for impairment whenever events or circumstances indicate that the carrying amount may not be recoverable over the remaining life of the asset or asset group. In 2019, we recorded a $ 145 impairment on the SKY Brasil trade name. In 2018, we wrote off approximately $ 2,892 of fully amortized trade names and $ 2,890 of fully amortized customer lists. In 2019, we began amortizing wireless licenses in Mexico over their average remaining economic life (see Note 1). Renewal fees on these licenses are recorded as intangible assets and amortized over the renewal term on a straight-line basis, generally 20 years. In 2019, we recorded $ 1,561 of these intangible assets, with the majority to be amortized over 20 years. Changes to our indefinite-lived wireless licenses in 2019 were partially due to the held-for-sale treatment of wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands (see Note 6).

Equity Method Investments

Equity Method Investments	12 Months Ended
	Dec. 31, 2019
Equity Method Investments
Equity Method Investments [Text Block]	NOTE 10. EQUITY METHOD INVESTMENTS Investments in partnerships, joint ventures and less than majority-owned subsidiaries in which we have significant influence are accounted for under the equity method. During the second quarter of 2019 , we sold our ownership in Hudson Yards and Hulu. (See Note 6) In 2018 2,135 at December 31, 2019. Of this amount, $1,397 is attributed to amortizing intangibles, which will be amortized into earnings in our “Equity net income (loss) of affiliates” over a weighted-average life of 19.4 years. The earnings from these investments, subsequent to the acquisition date, are included in the following table as well as our consolidated statements of income. Our investments in equity affiliates at December 31, 2019 primarily include our interests in HBO Latin America Group, Central European Media Enterprises Ltd. and SKY Mexico. HBO Latin America Group (HBO LAG) We hold an 88.2% interest in HBO LAG, which owns and operates various television channels in Latin America. We do not have the power to direct the activities that most significantly impact this entity’s economic performance, and therefore, account for this investment under the equity method of accounting. In October 2019 230. That agreement also included a call option for HBO Brasil, which we have not exercised. We expect the transaction to close in the second half of 2020 Central European Media Enterprises Ltd. (CME) We hold a 65.7% interest in CME, a broadcasting company that operates leading television networks in Bulgaria, the Czech Republic, Romania and the Slovak Republic, as well as develops and produces content for its television networks. We do not have the power to direct the activities that most significantly impact this entity’s economic performance, and therefore, account for this investment under the equity method of accounting. In October 2019 1,100. We expect the deal to close in the first half of 2020 SKY Mexico We hold a 41.3% interest in SKY Mexico, which is a leading pay-TV provider in Mexico. The following table is a reconciliation of our investments in equity affiliates as presented on our consolidated balance sheets: 2019 2018 Beginning of year $ 6,245 $ 1,560 Additional investments 448 237 Disposition of Hudson Yards ( 1,681) - Disposition of Hulu ( 689) - Disposition of Game Show Network ( 288) - Time Warner investments acquired - 4,912 Acquisition of remaining interest in Otter Media - ( 166) Equity in net income (loss) of affiliates 6 (48) Dividends and distributions received ( 301) ( 243) Currency translation adjustments ( 10) ( 14) Other adjustments ( 35) 7 End of year $ 3,695 $ 6,245

Inventories and Theatrical Film

Inventories and Theatrical Film and Television Production Costs	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories and Theatrical Film and Television Production Costs	NOTE 11. INVENTORIES AND THEATRICAL FILM AND TELEVISION PRODUCTION COSTS Film and television production costs are stated at the lower of cost, less accumulated amortization, or fair value and include the unamortized cost of completed theatrical films and television episodes, theatrical films and television series in production and undeveloped film and television rights. The amount of capitalized film and television production costs recognized as broadcast, programming and operations expenses for a given period is determined using the film forecast computation method. As of January 1, 2019, we reclassified $ 2,274 The following table summarizes inventories and theatrical film and television production costs as of December 31: 2019 2018 Inventories: Programming costs, less amortization 1 $ 4,599 $ 4,097 Other inventory, primarily DVD and Blu-ray Discs 96 146 Total inventories 4,695 4,243 Less: current portion of inventory ( 96) ( 2,420) Total noncurrent inventories 4,599 1,823 Theatrical film production costs: 2 Released, less amortization 392 451 Completed and not released 437 435 In production 1,475 866 Development and pre-production 171 159 Television production costs: 2 Released, less amortization 1,752 965 Completed and not released 1,344 1,087 In production 2,207 1,898 Development and pre-production 57 29 Total theatrical film and television production costs 7,835 5,890 Total noncurrent inventories and theatrical film and television production costs $ 12,434 $ 7,713 1 Includes the costs of certain programming rights, primarily sports, for which payments have been made prior to the related rights being received. 2 Does not include $ 5,967, and $ 7,826 of acquired film and television library intangible assets as of December 31, 2019, and 2018, respectively, which are included in “Other Intangible Assets – Net” on our consolidated balance sheet. Approximately 95% of unamortized film costs for released theatrical and television content are expected to be amortized within three years from December 31, 2019. In addition, approximately $ 2,195 of the film costs of released and completed and not released theatrical and television product are expected to be amortized during 2020.

Debt

Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure
Debt [Text Block]	NOTE 12. DEBT Long-term debt of AT&T and its subsidiaries, including interest rates and maturities, is summarized as follows at December 31: 2019 2018 Notes and debentures Interest Rates Maturities 1 1.80% - 2.99% 2019 - 2039 $ 17,404 $ 14,404 3.00% - 4.99% 2019 - 2050 102,595 104,291 5.00% - 6.99% 2019 - 2095 34,513 37,175 7.00% - 9.15% 2019 - 2097 5,050 5,976 Credit agreement borrowings 4,969 12,618 Other - 89 Fair value of interest rate swaps recorded in debt 26 ( 32) 164,557 174,521 Unamortized (discount) premium - net ( 2,996) ( 2,526) Unamortized issuance costs ( 452) ( 466) Total notes and debentures 161,109 171,529 Finance lease obligations 2,034 1,911 Total long-term debt, including current maturities 163,143 173,440 Current maturities of long-term debt ( 11,834) ( 7,190) Total long-term debt $ 151,309 $ 166,250 1 Maturities assume putable debt is redeemed by the holders at the next opportunity. We had outstanding Euro, British pound sterling, Canadian dollar, Mexican peso, Australian dollar, Brazilian real, and Swiss franc denominated debt of approximately $ 42,485 and $ 41,356 at December 31, 2019 and 2018, respectively. The weighted-average interest rate of our entire long-term debt portfolio, including the impact of derivatives, remained unchanged at 4.4 Current maturities of long-term debt include debt that may be put back to us by the holders in 2020. We have $ 1,000 of annual put reset securities that may be put each April until maturity in 2021 May, until maturity in 2022 500 in 2007 and partially exchanged in the 2017 debt exchange offers) is held to maturity, the redemption amount will be $ 592. Debt maturing within one year consisted of the following at December 31: 2019 2018 Current maturities of long-term debt $ 11,834 $ 7,190 Commercial paper - 3,048 Bank borrowings 1 4 4 Other - 13 Total $ 11,838 $ 10,255 1 Outstanding balance of short-term credit facility of a foreign subsidiary. Financing Activities During 2019, we received net proceeds of $ 17,039 on the issuance of $ 17,235 in long-term debt in various markets, with an average weighted maturity of approximately nine years and a weighted average coupon of 3.4%. We repaid $ 27,440 in borrowings of various notes with a weighted average coupon of 3.5%. In February 2020 2,619 of 4.600% global notes with an original maturity in 2045 2,995 of 4.000% global notes due 2049 Debt Exchange and Tender Offers In June 2019, we completed exchange tender offers. In the exchange offer, approximately $ 11,041 1.950% and 9.150%, were tendered and accepted in exchange for new series of AT&T Inc. global notes with interest rates and maturities that were identical to the interest rates and maturities of the tendered notes, as well as identical interest payment dates and substantially identical optional redemption provisions. Also, in June 2019 590 notes issued by WarnerMedia subsidiaries. On December 19, 2019, we purchased $ 1,409 of notes issued by various subsidiaries. As of December 31, 2019 and 2018, we were in compliance with all covenants and conditions of instruments governing our debt. Substantially all of our outstanding long-term debt is unsecured. Maturities of outstanding long-term notes and debentures, as of December 31, 2019, and the corresponding weighted-average interest rate scheduled for repayment are as follows: 2020 2021 2022 2023 2024 Thereafter Debt repayments 1 $ 12,149 $ 11,036 $ 11,189 $ 10,037 $ 11,225 $ 112,429 Weighted-average interest rate 2.9 % 3.8 % 3.5 % 3.5 % 3.6 % 4.8 % 1 Debt repayments assume putable debt is redeemed by the holders at the next opportunity. Credit Facilities General In December 2018 five-year five-year 7,500 revolving credit agreements totaling $ 15,000. The Amended and Restated Credit Agreement terminates on December 11, 2021 and the Five Year Credit Agreement terminates on December 11, 2023. No amounts were outstanding under either agreement as of December 31, 2019. In September 2019 1,300 term loan credit agreement containing (i) a 1.25 year $ 400 facility due in 2020 2.25 year $ 400 facility due in 2021 3.25 year $ 500 facility due in 2022 No Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement’s relevant Applicable Margin by 2.00% per annum. Revolving Credit Agreements The obligations of the lenders under the Amended and Restated Credit Agreement to provide advances will terminate on December 11, 2021, and under the Five Year Credit Agreement to provide advances will terminate on December 11, 2023, unless the commitments are terminated in whole prior to that date. All advances must be repaid no later than the date on which lenders are no longer obligated to make any advances under the applicable Credit Agreement. Each of the Credit Agreements provides that we and lenders representing more than 50% of the facility amount may agree to extend their commitments under such Credit Agreement for two one-year periods beyond the initial termination date. We have the right to terminate, in whole or in part, amounts committed by the lenders under each of the Credit Agreements in excess of any outstanding advances; however, any such terminated commitments may not be reinstated. Advances under these agreements would bear interest, at AT&T’s option, either:  at a variable annual rate equal to: (1) the highest of (but not less than zero) (a) the rate of interest announced publicly by Citibank in New York, New York, from time to time, as Citibank’s base rate, (b) 0.5% per annum above the federal funds rate, and (c) the London interbank offered rate (or the successor thereto) (“LIBOR”) applicable to dollars for a period of one month plus 1.00%, plus (2) an applicable margin, as set forth in the applicable Credit Agreement (the “Applicable Margin for Base Advances”); or  at a rate equal to: (i) LIBOR (adjusted upwards to reflect any bank reserve costs) for a period of one, two, three or six months, as applicable, plus (ii) an applicable margin, as set forth in the applicable Credit Agreement (the “Applicable Margin for Eurodollar Rate Advances”). We pay a facility fee of 0.070 0.080 0.100 0.125

Fair Value Measurements And Dis

Fair Value Measurements And Disclosure	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements And Disclosure
Fair Value Measurements And Disclosure [Text Block]	NOTE 13. FAIR VALUE MEASUREMENTS AND DISCLOSURE The Fair Value Measurement and Disclosure framework in ASC 820 provides a three-tiered fair value hierarchy based on the reliability of the inputs used to determine fair value. Level 1 refers to fair values determined based on quoted prices in active markets for identical assets. Level 2 refers to fair values estimated using significant other observable inputs and Level 3 includes fair values estimated using significant unobservable inputs. The level of an asset or liability within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Our valuation techniques maximize the use of observable inputs and minimize the use of unobservable inputs. The valuation methodologies described above may produce a fair value calculation that may not be indicative of future net realizable value or reflective of future fair values. We believe our valuation methods are appropriate and consistent with other market participants. The use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. There have been no changes in the methodologies used since December 31, 2018. Long-Term Debt and Other Financial Instruments The carrying amounts and estimated fair values of our long-term debt, including current maturities, and other financial instruments, are summarized as follows: December 31, 2019 December 31, 2018 Carrying Fair Carrying Fair Amount Value Amount Value Notes and debentures 1 $ 161,109 $ 182,124 $ 171,529 $ 172,287 Commercial paper - - 3,048 3,048 Bank borrowings 4 4 4 4 Investment securities 2 3,723 3,723 3,409 3,409 1 Includes credit agreement borrowings. 2 Excludes investments accounted for under the equity method. The carrying amount of debt with an original maturity of less than one year approximates fair value. The fair value measurements used for notes and debentures are considered Level 2 and are determined using various methods, including quoted prices for identical or similar securities in both active and inactive markets. Following is the fair value leveling for investment securities that are measured at fair value and derivatives as of December 31, 2019, and December 31, 2018. Derivatives designated as hedging instruments are reflected as “Other assets,” “Other noncurrent liabilities” and, for a portion of interest rate swaps, “Other current assets” on our consolidated balance sheets. December 31, 2019 Level 1 Level 2 Level 3 Total Equity Securities Domestic equities $ 844 $ - $ - $ 844 International equities 183 - - 183 Fixed income equities 229 - - 229 Available-for-Sale Debt Securities - 1,444 - 1,444 Asset Derivatives Interest rate swaps - 2 - 2 Cross-currency swaps - 172 - 172 Interest rate locks - 11 - 11 Foreign exchange contracts - 89 - 89 Liability Derivatives Cross-currency swaps - ( 3,187) - ( 3,187) Interest rate locks - ( 95) - ( 95) December 31, 2018 Level 1 Level 2 Level 3 Total Equity Securities Domestic equities $ 1,061 $ - $ - $ 1,061 International equities 256 - - 256 Fixed income equities 172 - - 172 Available-for-Sale Debt Securities - 870 - 870 Asset Derivatives Cross-currency swaps - 472 - 472 Foreign exchange contracts - 87 - 87 Liability Derivatives Interest rate swaps - ( 39) - ( 39) Cross-currency swaps - ( 2,563) - ( 2,563) Foreign exchange contracts - ( 2) - ( 2) Investment Securities Our investment securities include both equity and debt securities that are measured at fair value, as well as equity securities without readily determinable fair values. A substantial portion of the fair values of our investment securities is estimated based on quoted market prices. Investments in equity securities not traded on a national securities exchange are valued at cost, less any impairment, and adjusted for changes resulting from observable, orderly transactions for identical or similar securities. Investments in debt securities not traded on a national securities exchange are valued using pricing models, quoted prices of securities with similar characteristics or discounted cash flows. The components comprising total gains and losses in the period on equity securities are as follows: For the years ended December 31, 2019 2018 2017 Total gains (losses) recognized on equity securities $ 301 $ ( 130) $ 326 Gains (losses) recognized on equity securities sold 100 ( 10) 47 Unrealized gains (losses) recognized on equity securities held at end of period $ 201 $ ( 120) $ 279 At December 31, 2019, available-for-sale debt securities totaling $ 1,444 have maturities as follows - less than one year: $ 54; one to three years: $ 172; three to five years: $ 161; for five or more years: $ 1,057. Our cash equivalents (money market securities), short-term investments (certificate and time deposits) and nonrefundable customer deposits are recorded at amortized cost, and the respective carrying amounts approximate fair values. Short-term investments and nonrefundable customer deposits are recorded in “Other current assets” and our investment securities are recorded in “Other Assets” on the consolidated balance sheets. Derivative Financial Instruments We enter into derivative transactions to manage certain market risks, primarily interest rate risk and foreign currency exchange risk. This includes the use of interest rate swaps, interest rate locks, foreign exchange forward contracts and combined interest rate foreign exchange contracts (cross-currency swaps). We do not use derivatives for trading or speculative purposes. We record derivatives on our consolidated balance sheets at fair value that is derived from observable market data, including yield curves and foreign exchange rates (all of our derivatives are Level 2). Cash flows associated with derivative instruments are presented in the same category on the consolidated statements of cash flows as the item being hedged. Fair Value Hedging We designate our fixed-to-floating interest rate swaps as fair value hedges. The purpose of these swaps is to manage interest rate risk by managing our mix of fixed-rate and floating-rate debt. These swaps involve the receipt of fixed-rate amounts for floating interest rate payments over the life of the swaps without exchange of the underlying principal amount. We also designate some of our foreign exchange contracts as fair value hedges. The purpose of these contracts is to hedge currency risk associated with foreign-currency-denominated operating assets and liabilities. Accrued and realized gains or losses from fair value hedges impact the same category on the consolidated statements of income as the item being hedged. Unrealized gains on fair value hedges are recorded at fair market value as assets, and unrealized losses are recorded at fair market value as liabilities. Changes in the fair value of derivative instruments designated as fair value hedges are offset against the change in fair value of the hedged assets or liabilities through earnings. In the year ended December 31, 2019 and 2018, no ineffectiveness was measured on fair value hedges . Cash Flow Hedging We designate our cross-currency swaps as cash flow hedges. We have entered into multiple cross-currency swaps to hedge our exposure to variability in expected future cash flows that are attributable to foreign currency risk generated from the issuance of our foreign-denominated debt. These agreements include initial and final exchanges of principal from fixed foreign currency denominated amounts to fixed U.S. dollar denominated amounts, to be exchanged at a specified rate that is usually determined by the market spot rate upon issuance. They also include an interest rate swap of a fixed or floating foreign currency-denominated interest rate to a fixed U.S. dollar denominated interest rate. We also designate some of our foreign exchange contracts as cash flow hedges. The purpose of these contracts is to hedge certain film production costs denominated in foreign currencies. Unrealized gains on derivatives designated as cash flow hedges are recorded at fair value as assets, and unrealized losses are recorded at fair value as liabilities. For derivative instruments designated as cash flow hedges, the effective portion is reported as a component of accumulated OCI until reclassified into the consolidated statements of income in the same period the hedged transaction affects earnings. Periodically, we enter into and designate interest rate locks to partially hedge the risk of changes in interest payments attributable to increases in the benchmark interest rate during the period leading up to the probable issuance of fixed-rate debt. We designate our interest rate locks as cash flow hedges. Gains and losses when we settle our interest rate locks are amortized into income over the life of the related debt. Over the next 12 months, we expect to reclassify $ 61 from accumulated OCI to interest expense due to the amortization of net losses on historical interest rate locks. Net Investment Hedging We have designated € 1,450 million aggregate principal amount of debt as a hedge of the variability of some of the Euro-denominated net investments of our subsidiaries. The gain or loss on the debt that is designated as, and is effective as, an economic hedge of the net investment in a foreign operation is recorded as a currency translation adjustment within accumulated OCI, net on the consolidated balance sheet. Net gains on net investment hedges recognized in accumulated OCI for 2019 were $ 4. Collateral and Credit-Risk Contingency We have entered into agreements with our derivative counterparties establishing collateral thresholds based on respective credit ratings and netting agreements. At December 31, 2019, we had posted collateral of $ 204 (a deposit asset) and held collateral of $ 44 (a receipt liability). Under the agreements, if AT&T’s credit rating had been downgraded one rating level by Fitch Ratings, before the final collateral exchange in December, we would have been required to post additional collateral of $ 35. If AT&T’s credit rating had been downgraded four rating levels by Fitch Ratings, two levels by S&P, and two levels by Moody’s, we would have been required to post additional collateral of $ 2,678. If DIRECTV Holdings LLC’s credit rating had been downgraded below BBB- (S&P), we would have been required to post additional collateral of $ 232. At December 31, 2018, we had posted collateral of $ 1,675 (a deposit asset) and held collateral of $ 103 (a receipt liability). We do not offset the fair value of collateral, whether the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) exists, against the fair value of the derivative instruments. Following are the notional amounts of our outstanding derivative positions at December 31: 2019 2018 Interest rate swaps $ 853 $ 3,483 Cross-currency swaps 42,325 42,192 Interest rate locks 3,500 - Foreign exchange contracts 269 2,094 Total $ 46,947 $ 47,769 Following are the related hedged items affecting our financial position and performance: Effect of Derivatives on the Consolidated Statements of Income Fair Value Hedging Relationships For the years ended December 31, 2019 2018 2017 Interest rate swaps (Interest expense): Gain (Loss) on interest rate swaps $ 58 $ ( 12) $ ( 68) Gain (Loss) on long-term debt ( 58) 12 68 The net swap settlements that accrued and settled in the periods above were included in interest expense. Cash Flow Hedging Relationships For the years ended December 31, 2019 2018 2017 Cross-currency swaps: Gain (Loss) recognized in accumulated OCI $ ( 1,066) $ ( 825) $ 571 Foreign exchange contracts: Gain (Loss) recognized in accumulated OCI 10 51 - Other income (expense) - net reclassified from accumulated OCI into income 6 39 - Interest rate locks: Gain (Loss) recognized in accumulated OCI ( 84) - - Interest income (expense) reclassified from accumulated OCI into income ( 63) ( 58) ( 60)

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes [Abstract]
Income Taxes [Text Block]	NOTE 14. INCOME TAXES The Tax Cuts and Jobs Acts (the Act) was enacted on December 22, 2017. The Act reduces the U.S. federal corporate income tax rate from 35% to 21% and required companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred. ASC 740, “Income Taxes,” requires effects of changes in tax rates to be recognized in the period enacted. Recognizing the late enactment of the Act and complexity of accurately accounting for its impact, the Securities and Exchange Commission in SAB 118 provided guidance that allowed registrants to provide a reasonable estimate of the Act in their financial statements at December 31, 2017 and adjust the reported impact in a measurement period not to exceed one year. In 2018, we completed our accounting for the tax effects of the enactment of the Act and the measurement of our deferred tax assets and liabilities based on the rates at which they were expected to reverse in the future; the total benefit was $ 22,211, of which $ 20,271 was recorded in 2017 as a provisional amount. The total net benefit for the year ended December 31, 2018 was $ 718 for all enactment date and measurement period adjustments from the Act. The impact of the enactment of the Act is reflected in the following tables. Significant components of our deferred tax liabilities (assets) are as follows at December 31: 2019 2018 Depreciation and amortization $ 44,896 $ 43,105 Licenses and nonamortizable intangibles 17,355 17,561 Employee benefits ( 5,143) ( 5,366) Deferred fulfillment costs 3,050 2,679 Net operating loss and other carryforwards ( 7,301) ( 6,470) Other – net 1,536 1,651 Subtotal 54,393 53,160 Deferred tax assets valuation allowance 4,941 4,588 Net deferred tax liabilities $ 59,334 $ 57,748 Noncurrent deferred tax liabilities $ 59,502 $ 57,859 Less: Noncurrent deferred tax assets ( 168) ( 111) Net deferred tax liabilities $ 59,334 $ 57,748 At December 31, 2019, we had combined net operating and capital loss carryforwards (tax effected) for federal income tax purposes of $ 693, state of $ 970 and foreign of $ 2,948, expiring through 2039. Additionally, we had federal credit carryforwards of $ 664 and state credit carryforwards of $ 2,025, expiring primarily through 2039. We recognize a valuation allowance if, based on the weight of available evidence, it is more likely than not that some portion, or all, of a deferred tax asset will not be realized. Our valuation allowances at December 31, 2019 and 2018 related primarily to state and foreign net operating losses and state credit carryforwards. The Company considers post-1986 unremitted foreign earnings subjected to the one-time transition tax not to be indefinitely reinvested as such earnings can be repatriated without any significant incremental tax costs. U.S. income and foreign withholding taxes have not been recorded on temporary differences related to investments in certain foreign subsidiaries as such differences are considered indefinitely reinvested. Determination of the amount of unrecognized deferred tax liability is not practicable. We recognize the financial statement effects of a tax return position when it is more likely than not, based on the technical merits, that the position will ultimately be sustained. For tax positions that meet this recognition threshold, we apply our judgment, taking into account applicable tax laws, our experience in managing tax audits and relevant GAAP, to determine the amount of tax benefits to recognize in our financial statements. For each position, the difference between the benefit realized on our tax return and the benefit reflected in our financial statements is recorded on our consolidated balance sheets as an unrecognized tax benefit (UTB). We update our UTBs at each financial statement date to reflect the impacts of audit settlements and other resolutions of audit issues, the expiration of statutes of limitation, developments in tax law and ongoing discussions with taxing authorities. A reconciliation of the change in our UTB balance from January 1 to December 31 for 2019 and 2018 is as follows: Federal, State and Foreign Tax 2019 2018 Balance at beginning of year $ 10,358 $ 7,648 Increases for tax positions related to the current year 903 336 Increases for tax positions related to prior years 1,106 2,615 Decreases for tax positions related to prior years ( 1,283) ( 394) Lapse of statute of limitations ( 32) ( 52) Settlements ( 283) ( 664) Current year acquisitions 205 872 Foreign currency effects 5 ( 3) Balance at end of year 10,979 10,358 Accrued interest and penalties 2,708 2,588 Gross unrecognized income tax benefits 13,687 12,946 Less: Deferred federal and state income tax benefits ( 886) ( 811) Less: Tax attributable to timing items included above ( 4,320) ( 3,430) Less: UTBs included above that relate to acquired entities that would impact goodwill if recognized - ( 918) Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year $ 8,481 $ 7,787 Periodically we make deposits to taxing jurisdictions which reduce our UTB balance but are not included in the reconciliation above. The amount of deposits that reduced our UTB balance was $ 2,584 at December 31, 2019 and $ 2,115 at December 31, 2018. Accrued interest and penalties included in UTBs were $ 2,708 as of December 31, 2019, and $ 2,588 as of December 31, 2018. We record interest and penalties related to federal, state and foreign UTBs in income tax expense. The net interest and penalty expense included in income tax expense was $ 267 for 2019, $ 1,290 for 2018 and $ 107 for 2017. We file income tax returns in the U.S. federal jurisdiction and various state, local and foreign jurisdictions. As a large taxpayer, our income tax returns are regularly audited by the Internal Revenue Service (IRS) and other taxing authorities. The IRS has completed field examinations of our tax returns through 2010. All audit periods prior to 2003 are closed for federal examination purposes. Contested issues from our 2003 through 2010 returns are at various stages of resolution with the IRS Appeals Division. While we do not expect material changes, we are generally unable to estimate the range of impacts on the balance of uncertain tax positions or the impact on the effective tax rate from the resolution of these issues until the close of the examination process; and it is possible that the amount of unrecognized benefit with respect to our uncertain tax positions could increase or decrease within the next 12 months. The components of income tax (benefit) expense are as follows: 2019 2018 2017 Federal: Current $ 584 $ 3,258 $ 682 Deferred 1,656 277 ( 17,970) 2,240 3,535 ( 17,288) State and local: Current 603 513 79 Deferred 144 473 1,041 747 986 1,120 Foreign: Current 605 539 471 Deferred ( 99) ( 140) 989 506 399 1,460 Total $ 3,493 $ 4,920 $ ( 14,708) “Income Before Income Taxes” in the Consolidated Statements of Income included the following components for the years ended December 31: 2019 2018 2017 U.S. income before income taxes $ 18,301 $ 25,379 $ 16,438 Foreign income (loss) before income taxes 167 ( 506) ( 1,299) Total $ 18,468 $ 24,873 $ 15,139 A reconciliation of income tax expense (benefit) and the amount computed by applying the statutory federal income tax rate ( 21 35% for 2017) to income from continuing operations before income taxes is as follows: 2019 2018 2017 Taxes computed at federal statutory rate $ 3,878 $ 5,223 $ 5,299 Increases (decreases) in income taxes resulting from: State and local income taxes – net of federal income tax benefit 611 738 509 Enactment date and measurement period adjustments from the Act - ( 718) ( 20,271) Tax on foreign investments ( 115) ( 466) 73 Noncontrolling interest ( 230) ( 121) ( 133) Other – net ( 651) 264 ( 185) Total $ 3,493 $ 4,920 $ ( 14,708) Effective Tax Rate 18.9 % 19.8 % ( 97.2) %

Pension And Postretirement Bene

Pension And Postretirement Benefits	12 Months Ended
	Dec. 31, 2019
Pension And Postretirement Benefits
Pension And Postretirement Benefits [Text Block]	NOTE 15. PENSION AND POSTRETIREMENT BENEFITS We offer noncontributory pension programs covering the majority of domestic nonmanagement employees in our Communications business. Nonmanagement employees’ pension benefits are generally calculated using one of two formulas: a flat dollar amount applied to years of service according to job classification or a cash balance plan with negotiated annual pension band credits as well as interest credits. Most employees can elect to receive their pension benefits in either a lump sum payment or an annuity. Pension programs covering U.S. management employees are closed to new entrants. These programs continue to provide benefits to participants that were generally hired before January 1, 2015, who receive benefits under either cash balance pension programs that include annual or monthly credits based on salary as well as interest credits, or a traditional pension formula (i.e., a stated percentage of employees’ adjusted career income). We also provide a variety of medical, dental and life insurance benefits to certain retired employees under various plans and accrue actuarially determined postretirement benefit costs as active employees earn these benefits. WarnerMedia and certain of its subsidiaries have both funded and unfunded defined benefit pension plans, the substantial majority of which are noncontributory plans covering domestic employees. WarnerMedia also sponsors unfunded domestic postretirement benefit plans covering certain retirees and their dependents. At acquisition, the plans were already closed to new entrants and frozen for new accruals. In 2018, we recorded the fair value of the WarnerMedia plans using assumptions and accounting policies consistent with those disclosed by AT&T. Upon acquisition, the excess of projected benefit obligation over the plan assets was recognized as a liability and previously existing deferred actuarial gains and losses and unrecognized service costs or benefits were eliminated. In 2019, for certain management participants in our pension plan who terminated employment before April 1, 2019, we offered the option of more favorable 2018 interest rates and mortality basis for determining lump-sum distributions. We recorded special termination benefits of $ 81 associated with this offer in “Other income (expense) – net.” We also committed to a plan to offer certain terminated vested pension plan participants the opportunity to receive their benefit in a lump-sum amount. During the fourth quarter of 2019, we committed to plan changes impacting the cost of postretirement health and welfare benefits, which are reflected in our results. Future retirees will not receive health retirement subsidies but will have access to a new cost-efficient comprehensive plan. During 2018, we communicated and reflected in results the plan changes involving the frequency of future health reimbursement account credit increases, and the ability of certain participants of the pension plan to receive their benefit in a lump-sum amount upon retirement. Obligations and Funded Status For defined benefit pension plans, the benefit obligation is the projected benefit obligation, the actuarial present value, as of our December 31 measurement date, of all benefits attributed by the pension benefit formula to employee service rendered to that date. The amount of benefit to be paid depends on a number of future events incorporated into the pension benefit formula, including estimates of the average life of employees and their beneficiaries and average years of service rendered. It is measured based on assumptions concerning future interest rates and future employee compensation levels as applicable. For postretirement benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, the actuarial present value as of the measurement date of all future benefits attributed under the terms of the postretirement benefit plan to employee service. The following table presents the change in the projected benefit obligation for the years ended December 31: Pension Benefits Postretirement Benefits 2019 2018 2019 2018 Benefit obligation at beginning of year $ 55,439 $ 59,294 $ 19,378 $ 24,059 Service cost - benefits earned during the period 1,019 1,116 71 109 Interest cost on projected benefit obligation 1,960 2,092 675 778 Amendments - 50 ( 4,590) ( 1,145) Actuarial (gain) loss 7,734 ( 5,046) 2,050 ( 2,815) Special termination benefits 81 1 - 1 Benefits paid ( 6,356) ( 4,632) ( 1,543) ( 1,680) Acquisitions - 2,559 - 71 Plan transfers ( 4) 5 - - Benefit obligation at end of year $ 59,873 $ 55,439 $ 16,041 $ 19,378 The following table presents the change in the fair value of plan assets for the years ended December 31 and the plans’ funded status at December 31: Pension Benefits Postretirement Benefits 2019 2018 2019 2018 Fair value of plan assets at beginning of year $ 51,681 $ 45,463 $ 4,277 $ 5,973 Actual return on plan assets 8,207 ( 1,044) 609 ( 218) Benefits paid 1 ( 6,356) ( 4,632) ( 941) ( 1,503) Contributions 2 9,307 200 25 Acquisitions - 2,582 - - Plan transfers ( 4) 5 - - Fair value of plan assets at end of year 53,530 51,681 4,145 4,277 Unfunded status at end of year 2 $ ( 6,343) $ ( 3,758) $ ( 11,896) $ ( 15,101) 1 At our discretion, certain postretirement benefits may be paid from AT&T cash accounts, which does not reduce Voluntary Employee Benefit Association (VEBA) assets. Future benefit payments may be made from VEBA trusts and thus reduce those asset balances. 2 Funded status is not indicative of our ability to pay ongoing pension benefits or of our obligation to fund retirement trusts. Required pension funding is determined in accordance with the Employee Retirement Income Security Act of 1974, as amended (ERISA) and applicable regulations. In 2013, we made a voluntary contribution of a preferred equity interest in AT&T Mobility II LLC (Mobility II), the primary holding company for our wireless business, to the trust used to pay pension benefits under certain of our qualified pension plans. In 2018, we simplified transferability and enhanced marketability of the preferred equity interest, which resulted in it being recognized as a plan asset in our consolidated financial statements and reflected a noncash contribution of $ 8,803 included as “Contributions” in the above table. Since 2013, the preferred equity interest was a plan asset under ERISA and has been recognized as such in the plan’s separate financial statements. (See Note 17) Amounts recognized on our consolidated balance sheets at December 31 are listed below: Pension Benefits Postretirement Benefits 2019 2018 2019 2018 Current portion of employee benefit obligation 1 $ - $ - $ ( 1,365) $ ( 1,464) Employee benefit obligation 2 ( 6,343) ( 3,758) ( 10,531) ( 13,637) Net amount recognized $ ( 6,343) $ ( 3,758) $ ( 11,896) $ ( 15,101) 1 Included in “Accounts payable and accrued liabilities.” 2 Included in “Postemployment benefit obligation.” The accumulated benefit obligation for our pension plans represents the actuarial present value of benefits based on employee service and compensation as of a certain date and does not include an assumption about future compensation levels. The accumulated benefit obligation for our pension plans was $ 58,150 at December 31, 2019, and $ 53,963 at December 31, 2018. Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Income Periodic Benefit Costs Our combined net pension and postretirement cost (credit) recognized in our consolidated statements of income was $ 2,762, $( 4,251) and $ 155 for the years ended December 31, 2019, 2018 and 2017. The following table presents the components of net periodic benefit cost (credit): Pension Benefits Postretirement Benefits 2019 2018 2017 2019 2018 2017 Service cost – benefits earned during the period $ 1,019 $ 1,116 $ 1,128 $ 71 $ 109 $ 138 Interest cost on projected benefit obligation 1,960 2,092 1,936 675 778 809 Expected return on assets ( 3,561) ( 3,190) ( 3,134) ( 227) ( 304) ( 319) Amortization of prior service credit ( 113) ( 115) ( 123) ( 1,820) ( 1,635) ( 1,466) Actuarial (gain) loss 3,088 ( 812) 844 1,670 ( 2,290) 342 Net pension and postretirement cost (credit) $ 2,393 $ ( 909) $ 651 $ 369 $ ( 3,342) $ ( 496) Other Changes in Benefit Obligations Recognized in Other Comprehensive Income The following table presents the after-tax changes in benefit obligations recognized in OCI and the after-tax prior service credits that were amortized from OCI into net periodic benefit costs: Pension Benefits Postretirement Benefits 2019 2018 2017 2019 2018 2017 Balance at beginning of year $ 447 $ 571 $ 575 $ 6,086 $ 6,456 $ 5,089 Prior service (cost) credit - ( 37) ( 30) 3,457 864 1,120 Amortization of prior service credit ( 86) ( 87) ( 76) ( 1,372) ( 1,234) ( 907) Total recognized in other comprehensive (income) loss ( 86) ( 124) ( 106) 2,085 ( 370) 213 Adoption of ASU 2018-02 - - 102 - - 1,154 Balance at end of year $ 361 $ 447 $ 571 $ 8,171 $ 6,086 $ 6,456 Assumptions In determining the projected benefit obligation and the net pension and postretirement benefit cost, we used the following significant weighted-average assumptions: Pension Benefits Postretirement Benefits 2019 2018 2017 2019 2018 2017 Weighted-average discount rate for determining benefit obligation at December 31 3.40 % 4.50 % 3.80 % 3.20 % 4.40 % 3.70 % Discount rate in effect for determining service cost 1,2 4.10 % 4.20 % 4.60 % 4.40 % 4.30 % 4.60 % Discount rate in effect for determining interest cost 1,2 3.50 % 3.80 % 3.60 % 3.70 % 3.60 % 3.40 % Weighted-average interest crediting rate for cash balance pension programs 3 3.30 % 3.70 % 3.50 % - % - % - % Long-term rate of return on plan assets 7.00 % 7.00 % 7.75 % 5.75 % 5.75 % 5.75 % Composite rate of compensation increase for determining benefit obligation 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % Composite rate of compensation increase for determining net cost (benefit) 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % 1 Weighted-average discount rate for pension benefits in effect from January 1, 2019 through March 31, 2019 was 4.60% for service cost and 4.20% for interest cost, from April 1, 2019 through June 30, 2019 was 4.30% for service cost and 3.70% for interest cost, from July 1, 2019 through September 30, 2019 was 3.90% for service cost and 3.20% for interest cost, and, from October 1, 2019 through December 31, 2019 was 3.50% for service cost and 3.00% for interest cost. 2 Weighted-average discount rate for postretirement benefits in effect from January 1, 2019 through October 1, 2019 was 4.70% for service cost and 4.00% for interest cost, and, from October 2, 2019 through December 31, 2019 was 3.40% for service cost and 2.70% for interest cost. 3 Weighted-average interest crediting rates for cash balance pension programs relate only to the cash balance portion of total pension benefits. A 0.50% increase in the weighted-average interest crediting rate would increase the pension benefit obligation by $ 130. We recognize gains and losses on pension and postretirement plan assets and obligations immediately in “Other income (expense) – net” in our consolidated statements of income. These gains and losses are generally measured annually as of December 31, and accordingly, will normally be recorded during the fourth quarter, unless an earlier remeasurement is required. Should actual experience differ from actuarial assumptions, the projected pension benefit obligation and net pension cost and accumulated postretirement benefit obligation and postretirement benefit cost would be affected in future years. Discount Rate Our assumed weighted-average discount rate for pension and postretirement benefits of 3.40% and 3.20% respectively, at December 31, 2019, reflects the hypothetical rate at which the projected benefit obligation could be effectively settled or paid out to participants. We determined our discount rate based on a range of factors, including a yield curve composed of the rates of return on several hundred high-quality, fixed income corporate bonds available at the measurement date and corresponding to the related expected durations of future cash outflows. These bonds were all rated at least Aa3 or AA- by one of the nationally recognized statistical rating organizations, denominated in U.S. dollars, and neither callable, convertible nor index linked. For the year ended December 31, 2019, when compared to the year ended December 31, 2018, we decreased our pension discount rate by 1.10%, resulting in an increase in our pension plan benefit obligation of $ 8,018 and decreased our postretirement discount rate by 1.20%, resulting in an increase in our postretirement benefit obligation of $ 2,399. For the year ended December 31, 2018, we increased our pension discount rate by 0.70%, resulting in a decrease in our pension plan benefit obligation of $ 4,394 and increased our postretirement discount rates by 0.70%, resulting in a decrease in our postretirement benefit obligation of $ 1,509. We utilize a full yield curve approach in the estimation of the service and interest components of net periodic benefit costs for pension and other postretirement benefits. Under this approach, we apply discounting using individual spot rates from a yield curve composed of the rates of return on several hundred high-quality, fixed income corporate bonds available at the measurement date. These spot rates align to each of the projected benefit obligations and service cost cash flows. The service cost component relates to the active participants in the plan, so the relevant cash flows on which to apply the yield curve are considerably longer in duration on average than the total projected benefit obligation cash flows, which also include benefit payments to retirees. Interest cost is computed by multiplying each spot rate by the corresponding discounted projected benefit obligation cash flows. The full yield curve approach reduces any actuarial gains and losses based upon interest rate expectations (e.g., built-in gains in interest cost in an upward sloping yield curve scenario), or gains and losses merely resulting from the timing and magnitude of cash outflows associated with our benefit obligations. Neither the annual measurement of our total benefit obligations nor annual net benefit cost is affected by the full yield curve approach. Expected Long-Term Rate of Return In 2020, our expected long-term rate of return is 7.00% on pension plan assets and 4.75% on postretirement plan assets. Our expected long-term rate of return on postretirement plan assets was adjusted to 4.75% for 2020 from 5.75% for 2019 due to a change in the asset mix, holding more VEBA assets in cash and short-term fixed income securities. Our long-term rates of return reflect the average rate of earnings expected on the funds invested, or to be invested, to provide for the benefits included in the projected benefit obligations. In setting the long-term assumed rate of return, management considers capital markets’ future expectations, the asset mix of the plans’ investment and average historical asset return. Actual long-term returns can, in relatively stable markets, also serve as a factor in determining future expectations. We consider many factors that include, but are not limited to, historical returns on plan assets, current market information on long-term returns (e.g., long-term bond rates) and current and target asset allocations between asset categories. The target asset allocation is determined based on consultations with external investment advisers. If all other factors were to remain unchanged, we expect that a 0.50% decrease in the expected long-term rate of return would cause 2020 combined pension and postretirement cost to increase $ 273. However, any differences in the rate and actual returns will be included with the actuarial gain or loss recorded in the fourth quarter when our plans are remeasured. Composite Rate of Compensation Increase Our expected composite rate of compensation increase cost of 3.00% in 2019 and 2018 reflects the long-term average rate of salary increases. Mortality Tables At December 31, 2019, we updated our assumed mortality rates to reflect our best estimate of future mortality, which decreased our pension obligation by $ 147 and our postretirement obligations by $ 4. At December 31, 2018, we updated our assumed mortality rates, which decreased our pension obligation by $ 488 and our postretirement obligations by $ 61. Healthcare Cost Trend Our healthcare cost trend assumptions are developed based on historical cost data, the near-term outlook and an assessment of likely long-term trends. Based on historical experience, updated expectations of healthcare industry inflation and recent prescription drug cost experience, our 2020 assumed annual healthcare prescription drug cost trend and medical cost trend for eligible participants will decrease from an annual and ultimate trend rate of 4.50 4.00 102 2.50 3.00 Plan Assets Plan assets consist primarily of private and public equity, government and corporate bonds, and real assets (real estate and natural resources). The asset allocations of the pension plans are maintained to meet ERISA requirements. Any plan contributions, as determined by ERISA regulations, are made to a pension trust for the benefit of plan participants. We do not have significant ERISA required contributions to our pension plans for 2020. We maintain VEBA trusts to partially fund postretirement benefits; however, there are no ERISA or regulatory requirements that these postretirement benefit plans be funded annually. We made a discretionary contribution of $ 200 to our postretirement plan in December 2019 The principal investment objectives are to ensure the availability of funds to pay pension and postretirement benefits as they become due under a broad range of future economic scenarios, maximize long-term investment return with an acceptable level of risk based on our pension and postretirement obligations, and diversify broadly across and within the capital markets to insulate asset values against adverse experience in any one market. Each asset class has broadly diversified characteristics. Substantial biases toward any particular investing style or type of security are sought to be avoided by managing the aggregation of all accounts with portfolio benchmarks. Asset and benefit obligation forecasting studies are conducted periodically, generally every two to three years, or when significant changes have occurred in market conditions, benefits, participant demographics or funded status. Decisions regarding investment policy are made with an understanding of the effect of asset allocation on funded status, future contributions and projected expenses. The plans’ weighted-average asset targets and actual allocations as a percentage of plan assets, including the notional exposure of future contracts by asset categories at December 31, are as follows: Pension Assets Postretirement (VEBA) Assets Target 2019 2018 Target 2019 2018 Equity securities: Domestic 15 % - 25 % 17 % 16 % 15 % - 25 % 20 % 25 % International 7 % - 17 % 12 12 8 % - 18 % 12 18 Fixed income securities 29 % - 39 % 35 37 47 % - 57 % 52 39 Real assets 4 % - 14 % 9 9 - % - 6 % 1 1 Private equity 2 % - 12 % 8 8 - % - 7 % 2 2 Preferred interest 13 % - 23 % 17 18 - % - - % - - Other - % - 5 % 2 - 9 % - 19 % 13 15 Total 100 % 100 % 100 % 100 % At December 31, 2019, AT&T securities represented 17% of assets held by our pension trust, including preferred interest in Mobility II, and 3% of assets (primarily common stock) held by our VEBA trusts included in these financial statements. Investment Valuation Investments are stated at fair value. Fair value is the price that would be received to sell an asset or paid to transfer a liability at the measurement date. Investments in securities traded on a national securities exchange are valued at the last reported sales price on the final business day of the year. If no sale was reported on that date, they are valued at the last reported bid price. Investments in securities not traded on a national securities exchange are valued using pricing models, quoted prices of securities with similar characteristics or discounted cash flows. Shares of registered investment companies are valued based on quoted market prices, which represent the net asset value of shares held at year-end. Other commingled investment entities are valued at quoted redemption values that represent the net asset values of units held at year-end which management has determined approximates fair value. Real estate and natural resource direct investments are valued at amounts based upon appraisal reports. Fixed income securities valuation is based upon observable prices for comparable assets, broker/dealer quotes (spreads or prices), or a pricing matrix that derives spreads for each bond based on external market data, including the current credit rating for the bonds, credit spreads to Treasuries for each credit rating, sector add-ons or credits, issue-specific add-ons or credits as well as call or other options. The preferred interest is valued using an income approach by an independent fiduciary. Purchases and sales of securities are recorded as of the trade date. Realized gains and losses on sales of securities are determined on the basis of average cost. Interest income is recognized on the accrual basis. Dividend income is recognized on the ex-dividend date. Non-interest bearing cash and overdrafts are valued at cost, which approximates fair value. Fair Value Measurements See Note 13 for a discussion of fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The following tables set forth by level, within the fair value hierarchy, the pension and postretirement assets and liabilities at fair value as of December 31, 2019: Pension Assets and Liabilities at Fair Value as of December 31, 2019 Level 1 Level 2 Level 3 Total Non-interest bearing cash $ 85 $ - $ - $ 85 Interest bearing cash 529 - - 529 Foreign currency contracts - 5 - 5 Equity securities: Domestic equities 8,068 - 4 8,072 International equities 3,929 11 6 3,946 Preferred interest - - 8,806 8,806 Fixed income securities: Corporate bonds and other investments - 10,469 4 10,473 Government and municipal bonds 49 6,123 - 6,172 Mortgage-backed securities - 522 2 524 Real estate and real assets - - 2,817 2,817 Securities lending collateral 103 1,658 - 1,761 Receivable for variation margin 5 - - 5 Assets at fair value 12,768 18,788 11,639 43,195 Investments sold short and other liabilities at fair value ( 513) ( 2) - ( 515) Total plan net assets at fair value $ 12,255 $ 18,786 $ 11,639 $ 42,680 Assets held at net asset value practical expedient Private equity funds 4,544 Real estate funds 2,062 Commingled funds 5,710 Total assets held at net asset value practical expedient 12,316 Other assets (liabilities) 1 ( 1,466) Total Plan Net Assets $ 53,530 1 Other assets (liabilities) include amounts receivable, accounts payable and net adjustment for securities lending payable. Postretirement Assets and Liabilities at Fair Value as of December 31, 2019 Level 1 Level 2 Level 3 Total Interest bearing cash $ 248 $ 301 $ - $ 549 Equity securities: Domestic equities 438 - - 438 International equities 265 - - 265 Fixed income securities: Corporate bonds and other investments 7 492 31 530 Government and municipal bonds 6 182 1 189 Mortgage-backed securities - 294 - 294 Securities lending collateral - 36 - 36 Assets at fair value 964 1,305 32 2,301 Securities lending payable and other liabilities - ( 36) - ( 36) Total plan net assets at fair value $ 964 $ 1,269 $ 32 $ 2,265 Assets held at net asset value practical expedient Private equity funds 66 Real estate funds 27 Commingled funds 1,797 Total assets held at net asset value practical expedient 1,890 Other assets (liabilities) 1 ( 10) Total Plan Net Assets $ 4,145 1 Other assets (liabilities) include amounts receivable and accounts payable. The tables below set forth a summary of changes in the fair value of the Level 3 pension and postretirement assets for the year ended December 31, 2019: Pension Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 8,750 $ 4 $ 2,579 $ 11,333 Realized gains (losses) - - 64 64 Unrealized gains (losses) 58 - 45 103 Transfers in 8 5 134 147 Transfers out - ( 6) - ( 6) Purchases - 7 228 235 Sales - ( 4) ( 233) ( 237) Balance at end of year $ 8,816 $ 6 $ 2,817 $ 11,639 Postretirement Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 1 $ 12 $ - $ 13 Transfers in - 28 - 28 Transfers out - ( 1) - ( 1) Sales ( 1) ( 7) - ( 8) Balance at end of year $ - $ 32 $ - $ 32 The following tables set forth by level, within the fair value hierarchy, the pension and postretirement assets and liabilities at fair value as of December 31, 2018: Pension Assets and Liabilities at Fair Value as of December 31, 2018 Level 1 Level 2 Level 3 Total Non-interest bearing cash $ 52 $ - $ - $ 52 Interest bearing cash 167 41 - 208 Foreign currency contracts - 5 - 5 Equity securities: Domestic equities 6,912 - 1 6,913 International equities 3,594 8 - 3,602 Preferred interest - - 8,749 8,749 Fixed income securities: Corporate bonds and other investments - 10,719 4 10,723 Government and municipal bonds 51 6,170 - 6,221 Mortgage-backed securities - 382 - 382 Real estate and real assets - - 2,579 2,579 Securities lending collateral 12 1,466 - 1,478 Purchased options, futures, and swaps - 3 - 3 Receivable for variation margin 19 - - 19 Assets at fair value 10,807 18,794 11,333 40,934 Investments sold short and other liabilities at fair value ( 657) ( 6) - ( 663) Total plan net assets at fair value $ 10,150 $ 18,788 $ 11,333 $ 40,271 Assets held at net asset value practical expedient Private equity funds 4,384 Real estate funds 2,162 Commingled funds 5,740 Total assets held at net asset value practical expedient 12,286 Other assets (liabilities) 1 ( 876) Total Plan Net Assets $ 51,681 1 Other assets (liabilities) include amounts receivable, accounts payable and net adjustment for securities lending payable. Postretirement Assets and Liabilities at Fair Value as of December 31, 2018 Level 1 Level 2 Level 3 Total Interest bearing cash $ 45 $ 624 $ - $ 669 Equity securities: Domestic equities 745 8 - 753 International equities 541 - 1 542 Fixed income securities: Corporate bonds and other investments 7 602 11 620 Government and municipal bonds 2 377 1 380 Mortgage-backed securities - 283 - 283 Securities lending collateral - 63 - 63 Assets at fair value 1,340 1,957 13 3,310 Securities lending payable and other liabilities - ( 74) - ( 74) Total plan net assets at fair value $ 1,340 $ 1,883 $ 13 $ 3,236 Assets held at net asset value practical expedient Private equity funds 79 Real estate funds 36 Commingled funds 973 Total assets held at net asset value practical expedient 1,088 Other assets (liabilities) 1 ( 47) Total Plan Net Assets $ 4,277 1 Other assets (liabilities) include amounts receivable and accounts payable. The tables below set forth a summary of changes in the fair value of the Level 3 pension and postretirement assets for the year ended December 31, 2018: Pension Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 4 $ 2 $ 2,287 $ 2,293 Realized gains (losses) - - 120 120 Unrealized gains (losses) ( 408) ( 1) 170 ( 239) Transfers in 9,158 1 266 9,425 Transfers out ( 4) ( 1) - ( 5) Purchases - 8 85 93 Sales - ( 5) ( 349) ( 354) Balance at end of year $ 8,750 $ 4 $ 2,579 $ 11,333 Postretirement Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ - $ 5 $ - $ 5 Transfers in 1 8 - 9 Transfers out - ( 1) - ( 1) Purchases - 1 - 1 Sales - ( 1) - ( 1) Balance at end of year $ 1 $ 12 $ - $ 13 Estimated Future Benefit Payments Expected benefit payments are estimated using the same assumptions used in determining our benefit obligation at December 31, 2019. Because benefit payments will depend on future employment and compensation levels; average years employed; average life spans; and payment elections, among other factors, changes in any of these assumptions could significantly affect these expected amounts. The following table provides expected benefit payments under our pension and postretirement plans: Pension Benefits Postretirement Benefits 2020 $ 5,540 $ 1,539 2021 4,471 1,441 2022 4,362 1,343 2023 4,272 1,258 2024 4,174 1,015 Years 2025 - 2029 19,965 4,307 Supplemental Retirement Plans We also provide certain senior- and middle-management employees with nonqualified, unfunded supplemental retirement and savings plans. While these plans are unfunded, we have assets in a designated non-bankruptcy remote trust that are independently managed and used to provide for certain of these benefits. These plans include supplemental pension benefits as well as compensation-deferral plans, some of which include a corresponding match by us based on a percentage of the compensation deferral. For our supplemental retirement plans, the projected benefit obligation was $ 2,605 and the net supplemental retirement pension cost was $ 438 at and for the year ended December 31, 2019. The projected benefit obligation was $ 2,397 and the net supplemental retirement pension credit was $ 53 at and for the year ended December 31, 2018. We use the same significant assumptions for the composite rate of compensation increase in determining our projected benefit obligation and the net pension and postemployment benefit cost. Our discount rates of 3.20% at December 31, 2019 and 4.40% at December 31, 2018 were calculated using the same methodologies used in calculating the discount rate for our qualified pension and postretirement benefit plans. Deferred compensation expense was $ 199 in 2019, $ 128 in 2018 and $ 138 in 2017. Contributory Savings Plans We maintain contributory savings plans that cover substantially all employees. Under the savings plans, we match in cash or company stock a stated percentage of eligible employee contributions, subject to a specified ceiling. There are no debt-financed shares held by the Employee Stock Ownership Plans, allocated or unallocated. Our match of employee contributions to the savings plans is fulfilled with purchases of our stock on the open market or company cash. Benefit cost, which is based on the cost of shares or units allocated to participating employees’ accounts or the cash contributed to participant accounts, was $ 793, $ 724 and $ 703 for the years ended December 31, 2019, 2018 and 2017.

Share-Based Payment

Share-Based Payment	12 Months Ended
	Dec. 31, 2019
Share-Based Payment
Share-Based Payment [Text Block]	NOTE 16. SHARE-BASED PAYMENTS Under our various plans, senior and other management employees and nonemployee directors have received nonvested stock and stock units. In conjunction with the acquisition of Time Warner, restricted stock units issued under Time Warner plans were converted to AT&T share units that will be distributed in the form of AT&T common stock and cash. The shares will vest over a period of one four years in accordance with the terms of those plans. In addition, outstanding Time Warner stock options were converted to AT&T stock options that vested within one year. We do not intend to issue any additional grants under the Time Warner Inc. plans. Future grants to eligible employees will be issued under AT&T plans. We grant performance stock units, which are nonvested stock units, based upon our stock price at the date of grant and award them in the form of AT&T common stock and cash at the end of a three four five three 293 million shares of common stock (in addition to shares that may be issued upon exercise of outstanding options or upon vesting of performance stock units or other nonvested stock units) to officers, employees and directors pursuant to these various plans. We account for our share-based payment arrangements based on the fair value of the awards on their respective grant date, which may affect our ability to fully realize the value shown on our consolidated balance sheets of deferred tax assets associated with compensation expense. We record a valuation allowance when our future taxable income is not expected to be sufficient to recover the asset. Accordingly, there can be no assurance that the current stock price of our common shares will rise to levels sufficient to realize the entire tax benefit currently reflected on our consolidated balance sheets. However, to the extent we generate excess tax benefits (i.e., those additional tax benefits in excess of the deferred taxes associated with compensation expense previously recognized) the potential future impact on income would be reduced. Our consolidated statements of income include the compensation cost recognized for those plans as operating expenses, as well as the associated tax benefits, which are reflected in the table below: 2019 2018 2017 Performance stock units $ 544 $ 301 $ 395 Restricted stock and stock units 273 153 90 Other nonvested stock units 7 4 ( 5) Stock options ( 5) 5 - Total $ 819 $ 463 $ 480 Income tax benefit $ 202 $ 114 $ 184 A summary of the status of our nonvested stock units as of December 31, 2019, and changes during the year then ended is presented as follows (shares in millions): Nonvested Stock Units Shares Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2019 39 $ 38.44 Granted 27 31.18 Vested ( 21) 39.03 Forfeited ( 3) 34.26 Nonvested at December 31, 2019 42 $ 33.80 As of December 31, 2019, there was $ 693 of total unrecognized compensation cost related to nonvested share-based payment arrangements granted. That cost is expected to be recognized over a weighted-average period of 2.21 years. The total fair value of shares vested during the year was $ 798 for 2019, compared to $ 766 for 2018 and $ 473 for 2017. It is our intent to satisfy share option exercises using our treasury stock. Cash received from stock option exercises was $ 446 for 2019, $ 361 for 2018 and $ 33 for 2017.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Stockholder's Equity
Stockholders' Equity [Text Block]	NOTE 17. STOCKHOLDERS’ EQUITY Authorized Shares We have authorized 14 billion common shares of AT&T stock and 10 million preferred shares of AT&T stock, each with a par value of $ 1.00 48 thousand shares of Series A perpetual preferred stock, with a $ 25,000 per share liquidation preference, outstanding. There were no preferred shares outstanding at December 31, 2018. In February 2020, we issued 20 thousand shares of Series B cumulative perpetual preferred stock, with a € 100,000 per share liquidation preference, and an initial rate of 2.875%, subject to reset beginning after five years. We also issued 70 thousand shares of Series C, 4.75% cumulative perpetual preferred stock with a $ 25,000 per share liquidation preference. So long as the quarterly preferred dividends are declared and paid on a timely basis on each series of preferred shares, there are no limitations on our ability to declare a dividend on or repurchase AT&T common shares. The preferred shares are optionally redeemable by AT&T at the liquidation price on or after five years from the issuance date, or upon certain other contingent events. Stock Repurchase Program From time to time, we repurchase shares of common stock for distribution through our employee benefit plans or in connection with certain acquisitions. Our Board of Directors has approved the following authorizations to repurchase common stock: (1) March 2013 authorization program of 300 million shares, with 19 million outstanding at December 31, 2019 and (2) March 2014 authorization program for an additional 300 million shares, with all 300 million outstanding at December 31, 2019. To implement these authorizations, we used open market repurchase programs, relying on Rule 10b5-1 of the Securities Exchange Act of 1934, where feasible. We also use accelerated share repurchase programs with large financial institutions to repurchase our stock. During 2019, we repurchased approximately 56 million shares totaling $ 2,135 under the March 2013 authorization. Dividend Declarations In December 2019, AT&T declared a quarterly preferred dividend of $ 8 and an increase in its quarterly common dividend to $ 0.52 per share of common stock. In December 2018, AT&T declared an increase in its quarterly common dividend to $ 0.51 per share of common stock. Preferred Interests Issued by Subsidiaries We have issued cumulative perpetual preferred membership interests in certain subsidiaries. The preferred interests are entitled to cash distributions, subject to declaration. The preferred interests are included in “Noncontrolling interest” on the consolidated balance sheets. Mobility II We have issued 320 million Series A Cumulative Perpetual Preferred Membership Interests in Mobility II (Mobility preferred interests), representing all currently outstanding Mobility preferred equity interests, which pay cash distributions of $ 560 per annum, subject to declaration. So long as the distributions are declared and paid, the terms of the Mobility preferred equity interests will not impose any limitations on cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares. A holder of the Mobility preferred interests may put the interests to Mobility II on or after the earliest of certain events or September 9, 2020. Mobility II may redeem the interests upon a change in control of Mobility II or on or after September 9, 2022. When either options arise due to a passage of time, that option may be exercised only during certain periods. The price at which a put option or a redemption option can be exercised is the greater of (1) the market value of the interests as of the last date of the quarter preceding the date of the exercise of a put or redemption option and (2) the sum of (a) twenty-five dollars ($8,000 in the aggregate) plus (b) any accrued and unpaid distributions. The redemption price may be paid with cash, AT&T common stock, or a combination of cash and AT&T common stock, at Mobility II’s sole election. In no event shall Mobility II be required to deliver more than 250 million shares of AT&T common stock to settle put and redemption options. We have the intent and ability to settle the Mobility preferred equity interests with cash. The preferred interests are included in “Noncontrolling interest” on the consolidated balance sheets. Tower Holdings In 2019, we issued $ 6,000 nonconvertible cumulative preferred interests in a wireless subsidiary (Tower Holdings) that holds interests in various tower assets and have the right to receive approximately $ 6,000 if the purchase options from the tower companies are exercised. The membership interests in Tower Holdings consist of (1) common interests, which are held by a consolidated subsidiary of AT&T, and (2) two series of preferred interests (collectively the “Tower preferred interests”). The September series (Class A-1) of the preferred interests totals $ 1,500 and pays an initial preferred distribution of 5.0% , and the December series (Class A-2) totals $ 4,500 and pays an initial preferred distribution of 4.75% . Distributions are paid quarterly, subject to declaration, and reset every five years. Any failure to declare or pay distributions on the Tower preferred interests would not impose any limitation on cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares. We can call the Tower preferred interests at the issue price beginning five years from the issuance date or upon the receipt of proceeds from the sale of the underlying assets. The holders of the Tower preferred interests have the option to require redemption upon the occurrence of certain contingent events, such as the failure of AT&T to pay the preferred distribution for two or more periods or to meet certain other requirements, including a minimum credit rating. If notice is given upon such an event, all other holders of equal or more subordinate classes of membership interests in Tower Holdings are entitled to receive the same form of consideration payable to the holders of the preferred interests, resulting in a deemed liquidation for accounting purposes. The preferred interests are included in “Noncontrolling interest” on the consolidated balance sheets. PR Holdings In December 2019, we issued $ 1,950 nonconvertible cumulative preferred interests in a subsidiary (PR Holdings) that holds notes secured by the proceeds from the agreement to sell wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands. The membership interests in PR Holdings consist of (1) common interests, which are held by consolidated subsidiaries of AT&T, and (2) preferred interests (PR preferred interests). The PR preferred interests pay an initial preferred distribution at an annual rate of 4.75%. Distributions are paid quarterly, subject to declaration, and reset every five years. Any failure to declare or pay distributions on the PR preferred interests would not impose any limitation on cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares. We can call the PR preferred interests at the issue price beginning five years from the issuance date or upon the closing or termination of the sale of the underlying assets. The holders of the PR preferred interests have the option to require redemption upon the occurrence of certain contingent events, such as the failure of AT&T to pay the preferred distribution for two or more periods or to meet certain other requirements, including a minimum AT&T credit rating. If notice is given upon such an event, all other holders of equal or more subordinate classes of membership interests in PR Holdings are entitled to receive the same form of consideration payable to the holders of the preferred interests, resulting in a deemed liquidation for accounting purposes. The preferred interests are included in “Noncontrolling interest” on the consolidated balance sheets.

Sale of Receivables

Sale of Receivables	12 Months Ended
	Dec. 31, 2019
Other Assets [Abstract]
Finance Receivables Disclosure [Text Block]	NOTE 18. SALES OF RECEIVABLES We have agreements with various third-party financial institutions pertaining to the sales of certain types of our accounts receivable. The most significant of these programs are discussed in detail below and generally consist of (1) receivables arising from equipment installment plans, which are sold for cash and a deferred purchase price, and (2) receivables related to our WarnerMedia business. Under these programs, we transfer receivables to purchasers in exchange for cash and additional consideration upon settlement of the receivables, where applicable. Under the terms of our agreements for these programs, we continue to bill and collect the payments from our customers on behalf of the financial institutions. The sales of receivables did not have a material impact on our consolidated statements of income or to “Total Assets” reported on our consolidated balance sheets. We reflect cash receipts on sold receivables as cash flows from operations in our consolidated statements of cash flows. Cash receipts on the deferred purchase price are classified as cash flows from investing activities. Our equipment installment and WarnerMedia programs are discussed in detail below. The following table sets forth a summary of the receivables and accounts being serviced at December 31: 2019 2018 Equipment Equipment Installment WarnerMedia Installment WarnerMedia Gross receivables: $ 4,576 $ 3,324 $ 5,994 $ - Balance sheet classification Accounts receivable Notes receivable 2,467 - 3,457 - Trade receivables 477 2,809 438 - Other Assets Noncurrent notes and trade receivables 1,632 515 2,099 - Outstanding portfolio of receivables derecognized from our consolidated balance sheets 9,713 4,300 9,065 - Cash proceeds received, net of remittances 1 7,211 4,300 6,508 - 1 Represents amounts to which financial institutions remain entitled, excluding the deferred purchase price. Equipment Installment Receivables We offer our customers the option to purchase certain wireless devices in installments over a specified period of time and, in many cases, once certain conditions are met, they may be eligible to trade in the original equipment for a new device and have the remaining unpaid balance paid or settled. We maintain a program under which we transfer a portion of these receivables in exchange for cash and additional consideration upon settlement of the receivables, referred to as the deferred purchase price. In the event a customer trades in a device prior to the end of the installment contract period, we agree to make a payment to the financial institutions equal to any outstanding remaining installment receivable balance. Accordingly, we record a guarantee obligation for this estimated amount at the time the receivables are transferred. The following table sets forth a summary of equipment installment receivables sold: 2019 2018 2017 Gross receivables sold $ 9,921 $ 9,391 $ 8,058 Net receivables sold 1 9,483 8,871 7,388 Cash proceeds received 8,189 7,488 5,623 Deferred purchase price recorded 1,451 1,578 2,077 Guarantee obligation recorded 341 361 215 1 Receivables net of allowance, imputed interest and equipment trade-in right guarantees. The deferred purchase price and guarantee obligation are initially recorded at estimated fair value and subsequently carried at the lower of cost or net realizable value. The estimation of their fair values is based on remaining installment payments expected to be collected and the expected timing and value of device trade-ins. The estimated value of the device trade-ins considers prices offered to us by independent third parties that contemplate changes in value after the launch of a device model. The fair value measurements used for the deferred purchase price and the guarantee obligation are considered Level 3 under the Fair Value Measurement and Disclosure framework (see Note 13). The following table presents the previously transferred equipment installment receivables, which we repurchased in exchange for the associated deferred purchase price: 2019 2018 2017 Fair value of repurchased receivables $ 1,418 $ 1,480 $ 1,699 Carrying value of deferred purchase price 1,350 1,393 1,524 Gain on repurchases 1 $ 68 $ 87 $ 175 1 These gains are included in “Selling, general and administrative” in the consolidated statements of income. At December 31, 2019 and December 31, 2018, our deferred purchase price receivable was $ 2,336 and $ 2,370, respectively, of which $ 1,569 and $ 1,448 are included in “Other current assets” on our consolidated balance sheets, with the remainder in “Other Assets.” The guarantee obligation at December 31, 2019 and December 31, 2018 was $ 384 and $ 439, respectively, of which $ 148 and $ 196 are included in “Accounts payable and accrued liabilities” on our consolidated balance sheets, with the remainder in “Other noncurrent liabilities.” Our maximum exposure to loss as a result of selling these equipment installment receivables is limited to the total amount of our deferred purchase price and guarantee obligation. WarnerMedia Receivables In 2019, we entered into a revolving agreement to transfer up to $ 4,300 of certain receivables from our WarnerMedia business to various financial institutions on a recurring basis in exchange for cash equal to the gross receivables transferred. As customers pay their balances, we transfer additional receivables into the program, resulting in our gross receivables sold exceeding net cash flow impacts (e.g., collect and reinvest). The transferred receivables are fully guaranteed by our bankruptcy-remote subsidiary, which holds additional receivables in the amount of $ 3,324 that are pledged as collateral under this agreement. The transfers are recorded at fair value of the proceeds received and obligations assumed less derecognized receivables. Our maximum exposure to loss related to selling these receivables is limited to the amount outstanding. The following table sets forth a summary of WarnerMedia receivables sold: 2019 2018 2017 Gross receivables sold/cash proceeds received 1 $ 11,989 $ - $ - Collections reinvested under revolving agreement 7,689 - - Net cash proceeds received (remitted) $ 4,300 $ - $ - Net receivables sold 2 $ 11,604 $ - $ - Obligations recorded 530 - - 1 Includes initial sale of receivables of $ 4,300 for the year ended December 31, 2019. 2 Receivables net of allowance, return and incentive reserves and imputed interest.

Tower Transaction

Tower Transaction	12 Months Ended
	Dec. 31, 2019
Other Liabilities [Abstract]
Other Liabilities Disclosure [Text Block]	NOTE 19. TOWER TRANSACTION In December 2013, we closed our transaction with Crown Castle International Corp. (Crown Castle) in which Crown Castle gained the exclusive rights to lease and operate 9,048 wireless towers and purchased 627 of our wireless towers for $ 4,827 in cash. The leases have various terms with an average length of approximately 28 years. As the leases expire, Crown Castle will have fixed price purchase options for these towers totaling approximately $ 4,200, based on their estimated fair market values at the end of the lease terms. We sublease space on the towers from Crown Castle for an initial term of ten years at current market rates, subject to optional renewals in the future. We determined that we did not transfer control of the tower assets, which prevented us from achieving sale-leaseback accounting for the transaction, and we accounted for the cash proceeds from Crown Castle as a financing obligation on our consolidated balance sheets. We record interest on the financing obligation using the effective interest method at a rate of approximately 3.9%. The financing obligation is increased by interest expense and estimated future net cash flows generated and retained by Crown Castle from operation of the tower sites, and reduced by our contractual payments. We continue to include the tower assets in “Property, plant and equipment” on our consolidated balance sheets and depreciate them accordingly. At December 31, 2019 and 2018, the tower assets had a balance of $ 804 and $ 843, respectively. Our depreciation expense for these assets was $ 39 for each of 2019, 2018 and 2017. Payments made to Crown Castle under this arrangement were $ 244 for 2019. At December 31, 2019, the future minimum payments under the sublease arrangement are $ 248 for 2020, $ 253 for 2021, $ 258 for 2022, $ 264 for 2023, $ 269 for 2024 and $ 1,427 thereafter.

FirstNet

FirstNet	12 Months Ended
	Dec. 31, 2019
Contractors
Long-term Contracts or Programs Disclosure [Text Block]	NOTE 20. FIRSTNET In March 2017, the First Responder Network Authority (FirstNet) announced its selection of AT&T to build and manage the first nationwide broadband network dedicated to America’s first responders. All 56 jurisdictions, including 50 states, the District of Columbia and five U.S. territories, elected to participate in the network. Under the awarded 25-year agreement, FirstNet provided 20 MHz of valuable telecommunications spectrum and will provide success-based payments of $ 6,500 over the first five years to support network buildout. The spectrum provides priority use to first responders, which are included as wireless subscribers and contribute to our wireless revenues. As allowed under the agreement, excess capacity on the spectrum is used for any of AT&T’s subscriber base. Under the agreement, we are required to construct a network that achieves coverage and nationwide interoperability requirements. We have a contractual commitment to make sustainability payments of $ 18,000 over the 25-year contract. These sustainability payments represent our commitment to fund FirstNet’s operating expenses and future reinvestments in the network which we will own and operate. FirstNet has a statutory requirement to reinvest funds that exceed the agency’s operating expenses, which are anticipated to be in the $ 75-$ 100 range annually, and when including increases for inflation, we expect to be in the $ 3,000 or less range over the life of the 25-year contract. Being subject to federal acquisition rules, FirstNet is prohibited from contractually committing to a specific vendor for future network reinvestment. However, it is highly probable that AT&T will receive substantially all of the funds reinvested into the network since AT&T owns and operates the infrastructure and has exclusive rights to use the spectrum as all states have opted in. After FirstNet’s operating expenses are paid, we anticipate that the remaining amount, expected to be in the $15,000 range, will be reinvested into the network. As of December 31, 2019, we have submitted $ 360 in sustainability payments, with future payments under the agreement of $ 120 for 2020 and 2021; $ 195 for 2022, 2023 and 2024; and $ 16,815 thereafter. Amounts paid to FirstNet which are not expected to be returned to AT&T to be reinvested into our network will be expensed in the period paid. In the event FirstNet does not reinvest any funds to construct, operate, improve and maintain this network, our maximum exposure to loss is the total amount of the sustainability payments, which would be reflected in higher expense. The $ 6,500 of initial funding from FirstNet is contingent on the achievement of six operating capability milestones and certain first responder subscriber adoption targets. These milestones are based on coverage objectives of the first responder network during the construction period, which is expected to be over five years, and subscriber adoption targets. Funding payments to be received from FirstNet are reflected as a reduction from the costs capitalized in the construction of the network and, as appropriate, a reduction of associated operating expenses. As of December 31, 2019, we have completed certain task orders related to the construction of the network and have collected $ 3,372 to date from FirstNet. We have reflected these amounts as a reduction to the costs incurred to complete the task orders. We anticipate collecting the remainder of the $ 6,500 from FirstNet as we achieve milestones set out by FirstNet over the next three years.

Contingent Liabilities

Contingent Liabilities	12 Months Ended
	Dec. 31, 2019
Contingent Liabilities
Contingent Liabilities [Text Block]	NOTE 21. CONTINGENT LIABILITIES We are party to numerous lawsuits, regulatory proceedings and other matters arising in the ordinary course of business. In evaluating these matters on an ongoing basis, we take into account amounts already accrued on the balance sheet. In our opinion, although the outcomes of these proceedings are uncertain, they should not have a material adverse effect on our financial position, results of operations or cash flows. We have contractual obligations to purchase certain goods or services from various other parties. Our purchase obligations are expected to be approximately $ 16,590 in 2020, $ 21,121 in total for 2021 and 2022, $ 11,153 in total for 2023 and 2024 and $ 18,943 in total for years thereafter. See Note 13 for a discussion of collateral and credit-risk contingencies.

Additional Financial Informatio

Additional Financial Information	12 Months Ended
	Dec. 31, 2019
Additional Financial Information [Abstract]
Additional Financial Information [Text Block]	NOTE 22. ADDITIONAL FINANCIAL INFORMATION December 31, Consolidated Balance Sheets 2019 2018 Accounts payable and accrued liabilities: Accounts payable $ 29,640 $ 27,018 Accrued payroll and commissions 3,126 3,379 Current portion of employee benefit obligation 1,528 1,464 Accrued interest 2,498 2,557 Other 9,164 8,766 Total accounts payable and accrued liabilities $ 45,956 $ 43,184 Consolidated Statements of Income 2019 2018 2017 Advertising expense $ 6,121 $ 5,100 $ 3,772 Interest expense incurred $ 8,622 $ 8,450 $ 7,203 Capitalized interest ( 200) ( 493) ( 903) Total interest expense $ 8,422 $ 7,957 $ 6,300 Cash and Cash Flows We typically maintain our restricted cash balances for purchases and sales of certain investment securities and funding of certain deferred compensation benefit payments. The following table summarizes cash and cash equivalents and restricted cash balances contained on our consolidated balance sheets: December 31, Cash and Cash Equivalents and Restricted Cash 2019 2018 2017 2016 Cash and cash equivalents $ 12,130 $ 5,204 $ 50,498 $ 5,788 Restricted cash in Other current assets 69 61 6 7 Restricted cash in Other Assets 96 135 428 140 Cash and cash equivalents and restricted cash $ 12,295 $ 5,400 $ 50,932 $ 5,935 The following table summarizes cash paid during the periods for interest and income taxes: Consolidated Statements of Cash Flows 2019 2018 2017 Cash paid (received) during the year for: Interest $ 8,693 $ 8,818 $ 6,622 Income taxes, net of refunds 1,421 ( 354) 2,006 The following table provides supplemental disclosures for the statement of cash flows related to operating leases: 2019 Cash Flows from Operating Activities Cash paid for amounts included in lease obligations: Operating cash flows from operating leases $ 4,583 Supplemental Lease Cash Flow Disclosures Operating lease right-of-use assets obtained in exchange for new operating lease obligations 7,818 Noncash Investing and Financing Activities In connection with capital improvements and the acquisition of other productive assets, we negotiate favorable payment terms (referred to as vendor financing), which are reported as financing activities when paid. We recorded $ 2,632 of vendor financing commitments related to capital investments in 2019, $ 2,162 in 2018 and $ 1,000 in 2017. Labor Contracts As of January 31, 2020, we employed approximately 246,000 persons. Approximately 40% of our employees are represented by the Communications Workers of America (CWA), the International Brotherhood of Electrical Workers (IBEW) or other unions. After expiration of the agreements, work stoppages or labor disruptions may occur in the absence of new contracts or other agreements being reached. A contract covering approximately 13,000 traditional wireline employees in our West region expires in April 2020. Other contracts covering approximately 7,000 employees are scheduled to expire during 2020.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information (Unaudited)
Quarterly Financial Information (Unaudited) [Text Block]	NOTE 23. QUARTERLY FINANCIAL INFORMATION (UNAUDITED) The following tables represent our quarterly financial results: 2019 Calendar Quarter First 1 Second 1 Third 1 Fourth 1,2 Annual Total Operating Revenues $ 44,827 $ 44,957 $ 44,588 $ 46,821 $ 181,193 Operating Income 7,233 7,500 7,901 5,321 27,955 Net Income 4,348 3,974 3,949 2,704 14,975 Net Income Attributable to AT&T 4,096 3,713 3,700 2,394 13,903 Basic Earnings Per Share Attributable to Common Stock 3 $ 0.56 $ 0.51 $ 0.50 $ 0.33 $ 1.90 Diluted Earnings Per Share Attributable to Common Stock 3 $ 0.56 $ 0.51 $ 0.50 $ 0.33 $ 1.89 Stock Price High $ 31.64 $ 33.55 $ 38.75 $ 39.70 Low 28.30 30.05 31.52 36.40 Close 31.36 33.51 37.84 39.08 1 Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15). 2 Includes an asset abandonment charge (Note 7). 3 Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year. 2018 Calendar Quarter First 1 Second 1 Third Fourth 1 Annual Total Operating Revenues $ 38,038 $ 38,986 $ 45,739 $ 47,993 $ 170,756 Operating Income 6,201 6,466 7,269 6,160 26,096 Net Income 4,759 5,248 4,816 5,130 19,953 Net Income Attributable to AT&T 4,662 5,132 4,718 4,858 19,370 Basic Earnings Per Share Attributable to Common Stock 2 $ 0.75 $ 0.81 $ 0.65 $ 0.66 $ 2.85 Diluted Earnings Per Share Attributable to Common Stock 2 $ 0.75 $ 0.81 $ 0.65 $ 0.66 $ 2.85 Stock Price High $ 39.29 $ 36.39 $ 34.28 $ 34.30 Low 34.44 31.17 30.13 26.80 Close 35.65 32.11 33.58 28.54 1 Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15). 2 Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year.

Valuation And Qualifying Accoun

Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2019
Valuation And Qualifying Accounts
Valuation And Qualifying Accounts [Text Block]	SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS Allowance for Doubtful Accounts COL. A COL. B COL. C COL. D COL. E Additions (1) (2) (3) Balance at Charged to Charged to Beginning of Costs and Other Balance at End Period Expenses (a) Accounts (b) Acquisitions (c) Deductions (d) of Period Year 2019 $ 907 2,575 - - 2,247 $ 1,235 Year 2018 $ 663 1,791 - 179 1,726 $ 907 Year 2017 $ 661 1,642 - - 1,640 $ 663 (a) Includes amounts previously written off which were credited directly to this account when recovered. Excludes direct charges and credits to expense for nontrade receivables in the consolidated statements of income. (b) Includes amounts related to long-distance carrier receivables which were billed by AT&T. (c) Acqusition of Time Warner in 2018. (d) Amounts written off as uncollectible, or related to divested entities. SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS Allowance for Deferred Tax Assets COL. A COL. B COL. C COL. D COL. E Additions (1) (2) (3) Balance at Charged to Charged to Beginning of Costs and Other Acquisitions Deductions Balance at End Period Expenses Accounts (a) (b) (c) of Period Year 2019 $ 4,588 ( 18) 371 - - $ 4,941 Year 2018 $ 4,640 ( 210) ( 53) 211 - $ 4,588 Year 2017 $ 2,283 2,376 ( 19) - - $ 4,640 (a) Includes current year reclassifications from other balance sheet accounts. (b) Acquisition of Time Warner in 2018. (c) Reductions to valuation allowances related to deferred tax assets.

Summary Of Significant Accoun_2

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2019
Summary Of Significant Accounting Policies
Principles of Consolidation [Policy Text Block]	All significant intercompany transactions are eliminated in the consolidation process. Investments in less than majority-owned subsidiaries and partnerships where we have significant influence are accounted for under the equity method. Earnings from certain investments accounted for using the equity method are included for periods ended within up to one quarter of our period end. We also record our proportionate share of our equity method investees’ other comprehensive income (OCI) items, including translation adjustments. We treat distributions received from equity method investees as returns on investment and classify them as cash flows from operating activities until those distributions exceed our cumulative equity in the earnings of that investment. We treat the excess amount as a return of investment and classify it as cash flows from investing activities.
Basis of Accounting [Policy Text Block]	The preparation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes, including estimates of probable losses and expenses. Actual results could differ from those estimates. Certain prior period amounts have been conformed to the current period’s presentation.
Leases [Policy Text Block]	Leases As of January 1, 2019, we adopted, with modified retrospective The key change upon adoption of the standard was balance sheet recognition, given that the recognition of lease expense on our income statement is similar to our historical accounting. Using the modified retrospective transition method of adoption, we did not adjust the balance sheet for comparative periods practical expedients The adoption of ASC 842 resulted in the recognition of an operating lease liability of $ 22,121 20,960. The cumulative effect of the adoption to retained earnings was an increase of $ 316 reflecting the reclassification of deferred gains related to sale/leaseback transactions. The standard did not materially impact our income statements or statements of cash flows
Inventory, Policy [Policy Text Block]	Deferral of Episodic Television and Film Costs In March 2019, the FASB issued ASU No. 2019-02, “ Entertainment—Films—Other Assets—Film Costs (Subtopic 926-20) and Entertainment—Broadcasters—Intangibles—Goodwill and Other (Subtopic 920-350): Improvements to Accounting for Costs of Films and License Agreements for Program Materials” (ASU 2019-02), which we early adopted January 1, 2019 , with prospective programming inventory were eliminated. As of January 1, 2019, we reclassified $ 2,274 This change in accounting does not materially impact our income statement . Equipment Inventory Equipment inventories, which primarily consist of wireless devices and accessories, are included in “Other current assets” on our consolidated balance sheets. Equipment inventories are valued at the lower of cost or net realizable value and were $ 2,864 at December 31, 2019 and $ 2,771 at December 31, 2018. Licensed Programming Inventory Cost Recognition and Impairment We enter into agreements to license programming exhibition rights from licensors. A programming inventory asset related to these rights and a corresponding liability payable to the licensor are recorded (on a discounted basis if the license agreements are long-term) when (i) the cost of the programming is reasonably determined, (ii) the programming material has been accepted in accordance with the terms of the agreement, (iii) the programming is available for its first showing or telecast, and (iv) the license period has commenced. There are variations in the amortization methods of these rights, depending on whether the network is advertising-supported (e.g., TNT and TBS) or not advertising-supported (e.g., HBO and Turner Classic Movies). For the advertising-supported networks, our general policy is to amortize each program’s costs on a straight-line basis (or per-play basis, if greater) over its license period. In circumstances where the initial airing of the program has more value than subsequent airings, an accelerated method of amortization is used. The accelerated amortization upon the first airing versus subsequent airings is determined based on a study of historical and estimated future advertising sales for similar programming. For rights fees paid for sports programming arrangements, such rights fees are amortized using a revenue-forecast model, in which the rights fees are amortized using the ratio of current period advertising revenue to total estimated remaining advertising revenue over the term of the arrangement. For premium pay television, streaming and over-the-top (OTT) services that are not advertising-supported, each licensed program’s costs are amortized on a straight-line basis over its license period or estimated period of use, beginning with the month of initial exhibition. When we have the right to exhibit feature theatrical programming in multiple windows over a number of years, historical audience viewership is used as the basis for determining the amount of programming amortization attributable to each window. Licensed programming inventory is carried at the lower of unamortized cost or fair value. For networks that generate both advertising and subscription revenues, the net realizable value of unamortized programming costs is generally evaluated based on the network’s programming taken as a whole. In assessing whether the programming inventory for a particular advertising-supported network is impaired, the net realizable value for all of the network’s programming inventory is determined based on a projection of the network’s profitability. This assessment would occur upon the occurrence of certain triggering events. Similarly, for premium pay television, streaming and OTT services that are not advertising-supported, an evaluation of the fair value of unamortized programming costs is performed based on services’ licensed programming taken as a whole. Specifically, the fair value for all premium pay television, streaming and OTT service licensed programming is determined based on projections of estimated subscription revenues less certain costs of delivering and distributing the licensed programming. Changes in management’s intended usage of a specific program, such as a decision to no longer exhibit that program and forgo the use of the rights associated with the program license, results in a reassessment of that program’s fair value, which could result in an impairment. (See Note 11) Film and Television Production Cost Recognition, Participations and Residuals and Impairments Film and television production costs on our consolidated balance sheets include the unamortized cost of completed theatrical films and television episodes, theatrical films and television series in production and undeveloped film and television rights. Film and television production costs are stated at the lower of cost, less accumulated amortization, or fair value. For films and television programs predominantly monetized individually, the amount of capitalized film and television production costs and the amount of participations and residuals to be recognized as broadcast, programming and operations expenses for a given film or television series in a particular period was determined using the film forecast computation method. Under this method, the amortization of capitalized costs and the accrual of participations and residuals was based on the proportion of the film’s (or television program’s) revenues recognized for such period to the film’s (or television program’s) estimated remaining ultimate revenues (i.e., the total revenue to be received throughout a film’s (or television program’s) life cycle). The process of estimating a film’s ultimate revenues requires us to make a series of judgments related to future revenue-generating activities associated with a particular film. We estimate the ultimate revenues, less additional costs to be incurred (including exploitation and participation costs), in order to determine whether the value of a film or television series is impaired and requires an immediate write-off of unrecoverable film and television production costs. To the extent that the ultimate revenues are adjusted, the resulting gross margin reported on the exploitation of that film or television series in a period is also adjusted. Prior to the theatrical release of a film, our estimates are based on factors such as the historical performance of similar films, the star power of the lead actors, the rating and genre of the film, pre-release market research (including test market screenings), international distribution plans and the expected number of theaters in which the film will be released. In the absence of revenues directly related to the exhibition of owned film or television programs on our television networks, premium pay television, streaming or OTT services, we estimate a portion of the unamortized costs that are representative of the utilization of that film or television program in that exhibition and expense such costs as the film or television program is exhibited. The period over which ultimate revenues are estimated was generally not to exceed ten years from the initial release of a motion picture or from the date of delivery of the first episode of an episodic television series. Estimates were updated based on information available during the film’s production and, upon release, the actual results of each film. For a film (or television program) predominantly monetized as part of a film (or television program) group, the amount of capitalized film and television production costs is amortized using a reasonably reliable estimate of the portion of unamortized film costs that is representative of the use of the film. Production costs are expensed as the film (or television program) is exhibited or exploited.
Revenue Recognition [Policy Text Block]	Revenue Recognition As of January 1, 2018 , we adopted ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” as modified (ASC 606), using the modified retrospective does not allow us to adjust prior periods 2,342 to retained earnings for the cumulative effect of the change, with an offsetting contract asset of $ 1,737, deferred contract acquisition costs of $ 1,454, other asset reductions of $ 239, other liability reductions of $ 212, deferred income tax liability of $ 787 and increase to noncontrolling interest of $ 35. (See Note 5)
Financial Instruments [Policy Text Block]	Financial Instruments As of January 1, 2018 , we adopted ASU No. 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01), which requires us to prospectively 658
Income Taxes [Policy Text Block]	Income Taxes We record deferred income taxes for temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the computed tax basis of those assets and liabilities. We record valuation allowances against the deferred tax assets (included, together with our deferred income tax assets, as part of our reportable net deferred income tax liabilities on our consolidated balance sheets), for which the realization is uncertain. We review these items regularly in light of changes in federal and state tax laws and changes in our business. The Tax Cuts and Jobs Act (the Act) was enacted on December 22, 2017. The Act reduced the U.S. federal corporate income tax rate from 35% to 21% and required companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred. Recognizing the late enactment of the Act and complexity of accurately accounting for its impact, the Securities and Exchange Commission (SEC) in Staff Accounting Bulletin (SAB) 118 provided guidance that allowed registrants to provide a reasonable estimate of the impact to their financial statements and adjust the reported impact in a measurement period not to exceed one year. We included the estimated impact of the Act in our financial results at or for the period ended December 31, 2017, with additional adjustments recorded in 2018. (See Note 14) In February 2018, the FASB issued ASU No. 2018-02, “Income Statement– Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” (ASU 2018-02), which allows entities the option to reclassify from accumulated OCI to retained earnings the stranded tax effects resulting from the application of the Act. We elected to adopt ASU 2018-02 in the period in which the estimated income tax effects of the Act were recognized, reflecting a $ 1,529 adjustment for 2017 in the consolidated statements of changes in stockholders’ equity. (See Note 3)
Cash And Cash Equivalents [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents include all highly liquid investments with original maturities of three months or less. The carrying amounts approximate fair value. At December 31, 2019, we held $ 2,654 in cash and $ 9,476 in money market funds and other cash equivalents. Of our total cash and cash equivalents, $ 2,681 resided in foreign jurisdictions, some of which is subject to restrictions on repatriation.
Allowance For Doubtful Accounts [Policy Text Block]	Allowance for Doubtful Accounts We record expense to maintain an allowance for doubtful accounts for estimated losses that result from the failure or inability of our customers to make required payments deemed collectible from the customer when the service was provided or product was delivered. When determining the allowance, we consider the probability of recoverability of accounts receivable based on past experience, taking into account current collection trends as well as general economic factors, including bankruptcy rates. Credit risks are assessed based on historical write-offs, net of recoveries, as well as an analysis of the aged accounts receivable balances with allowances generally increasing as the receivable ages. Accounts receivable may be fully reserved for when specific collection issues are known to exist, such as catastrophes or pending bankruptcies.
Property, Plant and Equipment [Policy Text Block]	Property, Plant and Equipment Property, plant and equipment is stated at cost, except for assets acquired using acquisition accounting, which are initially recorded at fair value (see Note 7). The cost of additions and substantial improvements to property, plant and equipment is capitalized, and includes internal compensation costs for these projects. The cost of maintenance and repairs of property, plant and equipment is charged to operating expenses. Property, plant and equipment costs are depreciated using straight-line methods over their estimated economic lives. Certain subsidiaries follow composite group depreciation methodology. Accordingly, when a portion of their depreciable property, plant and equipment is retired in the ordinary course of business, the gross book value is reclassified to accumulated depreciation, and no gain or loss is recognized on the disposition of these assets. Property, plant and equipment is reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. We recognize an impairment loss when the carrying amount of a long-lived asset is not recoverable. The carrying amount of a long-lived asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. See Note 7 for a discussion of asset abandonments. The liability for the fair value of an asset retirement obligation is recorded in the period in which it is incurred if a reasonable estimate of fair value can be made. In periods subsequent to initial measurement, we recognize period-to-period changes in the liability resulting from the passage of time and revisions to either the timing or the amount of the original estimate. The increase in the carrying value of the associated long-lived asset is depreciated over the corresponding estimated economic life.
Software Costs [Policy Text Block]	Software Costs We capitalize certain costs incurred in connection with developing or obtaining internal-use software. Capitalized software costs are included in “Property, Plant and Equipment” on our consolidated balance sheets. In addition, there is certain network software that allows the equipment to provide the features and functions unique to the AT&T network, which we include in the cost of the equipment categories for financial reporting purposes. We amortize our capitalized software costs over a three-year seven-year
Goodwill And Other Intangible Assets [Policy Text Block]	Goodwill and Other Intangible Assets We have the following major classes of intangible assets: goodwill; licenses, which include Federal Communications Commission (FCC) and other wireless licenses and orbital slots; distribution networks; film and television libraries; intellectual properties and franchises; trademarks and trade names; customer lists; and various other finite-lived intangible assets (see Note 9). Goodwill represents the excess of consideration paid over the fair value of identifiable net assets acquired in business combinations. Wireless licenses provide us with the exclusive right to utilize certain radio frequency spectrum to provide wireless communications services. While wireless licenses are issued for a fixed period of time (generally ten years), renewals of domestic wireless licenses have occurred routinely and at nominal cost. We have determined that there are currently no legal, regulatory, contractual, competitive, economic or other factors that limit the useful lives of our FCC wireless licenses. During the first quarter of 2019, in conjunction with the renewal process of certain wireless licenses in Mexico, we reassessed the estimated economic lives and renewal assumptions for these licenses. As a result, we have changed the life of these licenses from indefinite to finite-lived. On January 1, 2019, we began amortizing our wireless licenses in Mexico over their average remaining economic life of 25 years. This change in accounting does not materially impact our income statement. Orbital slots represent the space in which we operate the broadcast satellites that support our digital video entertainment service offerings. Similar to our FCC wireless licenses, there are limited legal and regulatory factors that constrain the useful lives of our orbital slots. We acquired the rights to the AT&T and other trade names in previous acquisitions, classifying certain of those trade names as indefinite-lived. We have the effective ability to retain these exclusive rights permanently at a nominal cost. Goodwill, FCC wireless licenses and other indefinite-lived intangible assets are not amortized but are tested at least annually for impairment. The testing is performed on the value as of October 1 each year, and compares the book values of the assets to their fair values. Goodwill is tested by comparing the carrying amount of each reporting unit, deemed to be our principal operating segments or one level below them, to the fair value using both discounted cash flow as well as market multiple approaches. FCC wireless licenses are tested on an aggregate basis, consistent with our use of the licenses on a national scope, using a discounted cash flow approach. Orbital slots are similarly aggregated for purposes of impairment testing and valued using a discounted cash flow approach. Trade names are tested by comparing their book values to their fair values calculated using a discounted cash flow approach on a presumed royalty rate derived from the revenues related to each brand name. Intangible assets that have finite useful lives are amortized over their estimated useful lives (see Note 9). Customer lists and relationships are amortized using primarily the sum-of-the-months-digits method of amortization over the period in which those relationships are expected to contribute to our future cash flows. Finite-lived trademarks and trade names and distribution networks are amortized using the straight-line method over the estimated useful life of the assets. Film library is amortized using the film forecast computation method, as previously disclosed. The remaining finite-lived intangible assets are generally amortized using the straight-line method.
Advertising Costs [Policy Text Block]	Advertising Costs We expense advertising costs for products and services or for promoting our corporate image as we incur them (see Note 22).
Foreign Currency Translation [Policy Text Block]	Foreign Currency Translation Our foreign subsidiaries and foreign investments generally report their earnings in their local currencies. We translate their foreign assets and liabilities at exchange rates in effect at the balance sheet dates. We translate their revenues and expenses using average rates during the year. The resulting foreign currency translation adjustments are recorded as a separate component of accumulated OCI in our consolidated balance sheets (see Note 3). Operations in countries with highly inflationary economies consider the U.S. dollar as the functional currency. We hedge a portion of the foreign currency exchange risk involved in certain foreign currency-denominated transactions, which we explain further in our discussion of our methods of managing our foreign currency risk (see Note 13).
Pension And Other Postretirement Benefits [Policy Text Block]	Pension and Other Postretirement Benefits See Note 15 for a comprehensive discussion of our pension and postretirement benefit expense, including a discussion of the actuarial assumptions, our policy for recognizing the associated gains and losses and our method used to estimate service and interest cost components.
New Accounting Pronouncements, Policy [Policy Text Block]	Credit Loss Standard In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13, as amended), which replaces the incurred loss impairment methodology under current GAAP. ASU 2016-13 affects trade receivables, loans and other financial assets that are not subject to fair value through net income, as defined by the standard. The amendments under ASU 2016-13 will be effective as of January 1, 2020, and interim periods within that year. We do not expect the standard to have a material impact on our financial statements. Income Taxes In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (ASU 2019-12), which is expected to simplify income tax accounting requirements in areas deemed costly and complex. The amendments under ASU 2019-12 will be effective as of January 1, 2021, and interim periods within that year, with early adoption permitted in its entirety as of the beginning of the year of adoption. At adoption, the guidance allows for modified retrospective application through a cumulative effect adjustment to retained earnings. We are evaluating ASU 2019-12 for its impact to our financial statements.

Revenue Recognition (Policy)

Revenue Recognition (Policy)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition, Deferred Revenue [Policy Text Block]	We report our revenues net of sales taxes and record certain regulatory fees, primarily Universal Service Fund (USF) fees, on a net basis. Wireless, Advanced Data, Legacy Voice & Data Services and Equipment Revenue We offer service-only contracts and contracts that bundle equipment used to access the services and/or with other service offerings. Some contracts have fixed terms and others are cancellable on a short-term basis (i.e., month-to-month arrangements). Examples of service revenues include wireless, video entertainment (e.g., AT&T U-verse and DIRECTV), strategic services (e.g., virtual private network service), and legacy voice and data (e.g., traditional local and long-distance). These services represent a series of distinct services that is considered a separate performance obligation. Service revenue is recognized when services are provided, based upon either usage (e.g., minutes of traffic/bytes of data processed) or period of time (e.g., monthly service fees). Some of our services require customer premises equipment that, when combined and integrated with AT&T’s specific network infrastructure, facilitate the delivery of service to the customer. In evaluating whether the equipment is a separate performance obligation, we consider the customer’s ability to benefit from the equipment on its own or together with other readily available resources and if so, whether the service and equipment are separately identifiable (i.e., is the service highly dependent on, or highly interrelated with the equipment). When the equipment does not meet the criteria to be a distinct performance obligation (e.g., equipment associated with certain video services), we allocate the total transaction price to the related service. When equipment is a distinct performance obligation, we record the sale of equipment when title has passed and the products are accepted by the customer. For devices sold through indirect channels (e.g., national dealers), revenue is recognized when the dealer accepts the device, not upon activation. Our equipment and service revenues are predominantly recognized on a gross basis, as most of our services do not involve a third party and we typically control the equipment that is sold to our customers. Revenue recognized from fixed term contracts that bundle services and/or equipment is allocated based on the stand-alone selling price of all required performance obligations of the contract (i.e., each item included in the bundle). Promotional discounts are attributed to each required component of the arrangement, resulting in recognition over the contract term. Stand-alone selling prices are determined by assessing prices paid for service-only contracts (e.g., arrangements where customers bring their own devices) and stand-alone device pricing. We offer the majority of our customers the option to purchase certain wireless devices in installments over a specified period of time, and, in many cases, they may be eligible to trade in the original equipment for a new device and have the remaining unpaid balance paid or settled. For customers that elect these equipment installment payment programs, at the point of sale, we recognize revenue for the entire amount of revenue allocated to the customer receivable net of fair value of the trade-in right guarantee. The difference between the revenue recognized and the consideration received is recorded as a note receivable when the devices are not discounted and our right to consideration is unconditional. When installment sales include promotional discounts (e.g., “buy one get one free”), the difference between revenue recognized and consideration received is recorded as a contract asset to be amortized over the contract term. Less commonly, we offer certain customers highly discounted devices when they enter into a minimum service agreement term. For these contracts, we recognize equipment revenue at the point of sale based on a stand-alone selling price allocation. The difference between the revenue recognized and the cash received is recorded as a contract asset that will amortize over the contract term. Our contracts allow for customers to frequently modify their arrangement, without incurring penalties in many cases. When a contract is modified, we evaluate the change in scope or price of the contract to determine if the modification should be treated as a new contract or if it should be considered a change of the existing contract. We generally do not have significant impacts from contract modifications. Revenues from transactions between us and our customers are recorded net of revenue-based regulatory fees and taxes. Cash incentives given to customers are recorded as a reduction of revenue. Nonrefundable, upfront service activation and setup fees associated with service arrangements are deferred and recognized over the associated service contract period or customer life. Subscription Revenue Subscription revenues from cable networks and premium pay and basic-tier television services are recognized over the license period as programming is provided to affiliates or digital distributors based on negotiated contractual programming rates. When a distribution contract with an affiliate has expired and a new distribution contract has not been executed, revenues are based on estimated rates, giving consideration to factors including the previous contractual rates, inflation, current payments by the affiliate and the status of the negotiations on a new contract. When the new distribution contract terms are finalized, an adjustment to revenue is recorded, if necessary, to reflect the new terms. Subscription revenues from end-user subscribers are recognized when services are provided, based upon either usage or period of time. Subscription revenues from streaming services are recognized as programming services are provided to customers. Content Revenue Feature films typically are produced or acquired for initial exhibition in theaters, followed by distribution, generally commencing within three years of such initial exhibition. Revenues from film rentals by theaters are recognized as the films are exhibited. Television programs and series are initially produced for broadcast and may be subsequently licensed or sold in physical format and/or electronic delivery. Revenues from the distribution of television programming through broadcast networks, cable networks, first-run syndication and streaming services are recognized when the programs or series are available to the licensee. In certain circumstances, pursuant to the terms of the applicable contractual arrangements, the availability dates granted to customers may precede the date in which the customer can be billed for these sales. Revenues from sales of feature films and television programming in physical format are recognized at the later of the delivery date or the date when made widely available for sale or rental by retailers based on gross sales less a provision for estimated returns, rebates and pricing allowances. Revenues from the licensing of television programs and series for electronic sell-through or video-on-demand are recognized when the product has been purchased by and made available to the consumer to either download or stream. Upfront or guaranteed payments for the licensing of intellectual property are recognized as revenue at either the inception of the license term if the intellectual property has significant standalone functionality or over the corresponding license term if the licensee’s ability to derive utility is dependent on our continued support of the intellectual property throughout the license term. Revenues from the sales of console games are recognized at the later of the delivery date or the date that the product is made widely available for sale or rental by retailers based on gross sales less a provision for estimated returns, rebates and pricing allowances. Advertising Revenue Advertising revenues are recognized, net of agency commissions, in the period that the advertisements are aired. If there is a targeted audience guarantee, revenues are recognized for the actual audience delivery and revenues are deferred for any shortfall until the guaranteed audience delivery is met, typically by providing additional advertisements. Advertising revenues from digital properties are recognized as impressions are delivered or the services are performed.

Fair Value Measurements and D_2

Fair Value Measurements and Disclosure (Policy)	12 Months Ended
	Dec. 31, 2019
Derivatives Policy [Abstract]
Derivatives netting policy	We do not offset the fair value of collateral, whether the right to reclaim cash collateral (a receivable) or the obligation to return cash collateral (a payable) exists, against the fair value of the derivative instruments.

Pension and Postretirement Be_2

Pension and Postretirement Benefits (Policy)	12 Months Ended
	Dec. 31, 2019
Pension And Postretirement Benefits
Recognition of actuarial gains and losses [Policy Text Block]	We recognize gains and losses on pension and postretirement plan assets and obligations immediately in “Other income (expense) – net” in our consolidated statements of income. These gains and losses are generally measured annually as of December 31, and accordingly, will normally be recorded during the fourth quarter, unless an earlier remeasurement is required.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share
Reconciliation Of The Numerators And Denominators Of Basic Earnings Per Share And Diluted Earnings Per Share [Table Text Block]	NOTE 2. EARNINGS PER SHARE A reconciliation of the numerators and denominators of basic and diluted earnings per share is shown in the table below: Year Ended December 31, 2019 2018 2017 Numerators Numerator for basic earnings per share: Net income $ 14,975 $ 19,953 $ 29,847 Less: Net income attributable to noncontrolling interest ( 1,072) ( 583) ( 397) Net income attributable to AT&T 13,903 19,370 29,450 Less: Preferred stock dividends ( 3) - - Net income attributable to common stock 13,900 19,370 29,450 Dilutive potential common shares: Share-based payment 21 19 13 Numerator for diluted earnings per share $ 13,921 $ 19,389 $ 29,463 Denominators (000,000) Denominator for basic earnings per share: Weighted-average number of common shares outstanding 7,319 6,778 6,164 Dilutive potential common shares: Share-based payment (in shares) 29 28 19 Denominator for diluted earnings per share 7,348 6,806 6,183 Basic earnings per share attributable to Common Stock $ 1.90 $ 2.85 $ 4.77 Diluted earnings per share attributable to Common Stock $ 1.89 $ 2.85 $ 4.76

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Income [Abstract]
Accumulated Other Comprehensive Income [Table Text Block]	NOTE 3. OTHER COMPREHENSIVE INCOME Changes in the balances of each component included in accumulated OCI are presented below. All amounts are net of tax and exclude noncontrolling interest. Foreign Currency Translation Adjustment Net Unrealized Gains (Losses) on Available-for-Sale Securities Net Unrealized Gains (Losses) on Cash Flow Hedges Defined Benefit Postretirement Plans Accumulated Other Comprehensive Income Balance as of December 31, 2016 $ ( 1,995) $ 541 $ 744 $ 5,671 $ 4,961 Other comprehensive income (loss) before reclassifications 20 187 371 1,083 1,661 Amounts reclassified from accumulated OCI - 1 ( 185) 1 39 2 ( 988) 3 ( 1,134) Net other comprehensive income (loss) 20 2 410 95 527 Amounts reclassified to retained earnings 4 ( 79) 117 248 1,243 1,529 Balance as of December 31, 2017 ( 2,054) 660 1,402 7,009 7,017 Other comprehensive income (loss) before reclassifications ( 1,030) ( 4) ( 597) 830 ( 801) Amounts reclassified from accumulated OCI - 1 - 1 13 2 ( 1,322) 3 ( 1,309) Net other comprehensive income (loss) ( 1,030) ( 4) ( 584) ( 492) ( 2,110) Amounts reclassified to retained earnings 5 - ( 658) - - ( 658) Balance as of December 31, 2018 ( 3,084) ( 2) 818 6,517 4,249 Other comprehensive income (loss) before reclassifications 28 50 ( 900) 3,457 2,635 Amounts reclassified from accumulated OCI - 1 - 1 45 2 ( 1,459) 3 ( 1,414) Net other comprehensive income (loss) 28 50 ( 855) 1,998 1,221 Balance as of December 31, 2019 $ ( 3,056) $ 48 $ ( 37) $ 8,515 $ 5,470 1 (Gains) losses are included in Other income (expense) - net in the consolidated statements of income. 2 (Gains) losses are included in Interest expense in the consolidated statements of income (see Note 13). 3 The amortization of prior service credits associated with postretirement benefits is included in Other income (expense) in the consolidated statements of income (see Note 15). 4 With the adoption of ASU 2018-02, the stranded tax effects resulting from the application of the Tax Cuts and Jobs Act are reclassified to retained earnings (see Note 1). 5 With the adoption of ASU 2016-01, the unrealized (gains) losses on our equity investments are reclassified to retained earnings (see Note 1).

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Information
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	For the year ended December 31, 2019 Revenues Operations and Support Expenses EBITDA Depreciation and Amortization Operating Income (Loss) Equity in Net Income (Loss) of Affiliates Segment Contribution Communications Mobility $ 71,056 $ 40,681 $ 30,375 $ 8,054 $ 22,321 $ - $ 22,321 Entertainment Group 45,126 35,028 10,098 5,276 4,822 - 4,822 Business Wireline 26,177 16,091 10,086 4,999 5,087 - 5,087 Total Communications 142,359 91,800 50,559 18,329 32,230 - 32,230 WarnerMedia Turner 13,122 7,740 5,382 235 5,147 52 5,199 Home Box Office 6,749 4,312 2,437 102 2,335 30 2,365 Warner Bros. 14,358 11,816 2,542 162 2,380 ( 30) 2,350 Other ( 730) ( 71) ( 659) 39 ( 698) 110 ( 588) Total WarnerMedia 33,499 23,797 9,702 538 9,164 162 9,326 Latin America Vrio 4,094 3,378 716 660 56 27 83 Mexico 2,869 3,085 ( 216) 502 ( 718) - ( 718) Total Latin America 6,963 6,463 500 1,162 ( 662) 27 ( 635) Xandr 2,022 646 1,376 58 1,318 - 1,318 Segment Total 184,843 122,706 62,137 20,087 42,050 $ 189 $ 42,239 Corporate and Other Corporate 1,675 3,008 ( 1,333) 629 ( 1,962) Acquisition-related items ( 72) 960 ( 1,032) 7,460 ( 8,492) Certain significant items - 2,082 ( 2,082) 43 ( 2,125) Eliminations and consolidations ( 5,253) ( 3,735) ( 1,518) ( 2) ( 1,516) AT&T Inc. $ 181,193 $ 125,021 $ 56,172 $ 28,217 $ 27,955 For the year ended December 31, 2018 Revenues Operations and Support Expenses EBITDA Depreciation and Amortization Operating Income (Loss) Equity in Net Income (Loss) of Affiliates Segment Contribution Communications Mobility $ 70,521 $ 40,690 $ 29,831 $ 8,263 $ 21,568 $ - $ 21,568 Entertainment Group 46,460 36,430 10,030 5,315 4,715 - 4,715 Business Wireline 26,740 16,201 10,539 4,714 5,825 - 5,825 Total Communications 143,721 93,321 50,400 18,292 32,108 - 32,108 WarnerMedia Turner 6,979 3,794 3,185 131 3,054 54 3,108 Home Box Office 3,598 2,187 1,411 56 1,355 29 1,384 Warner Bros. 8,703 7,130 1,573 96 1,477 ( 28) 1,449 Other ( 339) ( 145) ( 194) 22 ( 216) ( 30) ( 246) Total WarnerMedia 18,941 12,966 5,975 305 5,670 25 5,695 Latin America Vrio 4,784 3,743 1,041 728 313 34 347 Mexico 2,868 3,415 ( 547) 510 ( 1,057) - ( 1,057) Total Latin America 7,652 7,158 494 1,238 ( 744) 34 ( 710) Xandr 1,740 398 1,342 9 1,333 - 1,333 Segment Total 172,054 113,843 58,211 19,844 38,367 $ 59 $ 38,426 Corporate and Other Corporate 2,150 2,250 ( 100) 1,630 ( 1,730) Acquisition-related items ( 49) 1,185 ( 1,234) 6,931 ( 8,165) Certain significant items - 899 ( 899) 26 ( 925) Eliminations and consolidations ( 3,399) ( 1,947) ( 1,452) ( 1) ( 1,451) AT&T Inc. $ 170,756 $ 116,230 $ 54,526 $ 28,430 $ 26,096 For the year ended December 31, 2017 Revenues Operations and Support Expenses EBITDA Depreciation and Amortization Operating Income (Loss) Equity in Net Income (Loss) of Affiliates Segment Contribution Communications Mobility $ 70,259 $ 42,317 $ 27,942 $ 7,931 $ 20,011 $ - $ 20,011 Entertainment Group 49,995 38,903 11,092 5,621 5,471 - 5,471 Business Wireline 29,203 18,441 10,762 4,756 6,006 - 6,006 Total Communications 149,457 99,661 49,796 18,308 31,488 - 31,488 WarnerMedia Turner 430 331 99 4 95 45 140 Home Box Office - - - - - - - Warner Bros. - - - - - - - Other - 4 ( 4) - ( 4) ( 74) ( 78) Total WarnerMedia 430 335 95 4 91 ( 29) 62 Latin America Vrio 5,456 4,172 1,284 849 435 87 522 Mexico 2,813 3,232 ( 419) 369 ( 788) - ( 788) Total Latin America 8,269 7,404 865 1,218 ( 353) 87 ( 266) Xandr 1,373 169 1,204 2 1,202 - 1,202 Segment Total 159,529 107,569 51,960 19,532 32,428 $ 58 $ 32,486 Corporate and Other Corporate 2,443 3,911 ( 1,468) 214 ( 1,682) Acquisition-related items - 798 ( 798) 4,608 ( 5,406) Certain significant items ( 243) 3,880 ( 4,123) 33 ( 4,156) Eliminations and consolidations ( 1,183) 31 ( 1,214) - ( 1,214) AT&T Inc. $ 160,546 $ 116,189 $ 44,357 $ 24,387 $ 19,970
Reconciliation of Operating Income (Loss) from Segments to Consolidated [Table Text Block]	The following table is a reconciliation of operating income (loss) to Income Before Income Taxes reported in our consolidated statements of income: 2019 2018 2017 Communications $ 32,230 $ 32,108 $ 31,488 WarnerMedia 9,326 5,695 62 Latin America ( 635) ( 710) ( 266) Xandr 1,318 1,333 1,202 Segment Contribution 42,239 38,426 32,486 Reconciling Items: Corporate and Other ( 1,962) ( 1,730) ( 1,682) Merger and integration items ( 1,032) ( 1,234) ( 798) Amortization of intangibles acquired ( 7,460) ( 6,931) ( 4,608) Abandonments and impairments ( 1,458) ( 46) ( 2,914) Employee separation charges ( 624) ( 587) ( 445) Other noncash charges (credits), net ( 43) ( 111) 49 Natural disaster items - ( 181) ( 626) Tax reform special bonus - - ( 220) Segment equity in net income of affiliates ( 189) ( 59) ( 58) Eliminations and consolidations ( 1,516) ( 1,451) ( 1,214) AT&T Operating Income 27,955 26,096 19,970 Interest Expense 8,422 7,957 6,300 Equity in net income (loss) of affiliates 6 ( 48) ( 128) Other income (expense) - net ( 1,071) 6,782 1,597 Income Before Income Taxes $ 18,468 $ 24,873 $ 15,139
Schedule of Revenues by Geographic Region [Table Text Block]	The following table sets forth revenues earned from customers, and property, plant and equipment located in different geographic areas. 2019 2018 2017 Revenues Net Property, Plant & Equipment Revenues Net Property, Plant & Equipment Revenues Net Property, Plant & Equipment United States $ 162,344 $ 122,567 $ 154,795 $ 123,457 $ 149,841 $ 118,200 Europe 6,137 1,854 4,073 1,634 1,064 392 Mexico 3,198 3,648 3,100 3,467 2,913 3,619 Brazil 2,761 1,057 2,724 1,213 2,948 1,447 All other Latin America 3,219 544 3,055 1,217 2,743 1,294 Asia/Pacific Rim 2,651 390 2,214 408 829 194 Other 883 68 795 77 208 76 Total $ 181,193 $ 130,128 $ 170,756 $ 131,473 $ 160,546 $ 125,222
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following tables present intersegment revenues, assets, investments in equity affiliates and capital expenditures by segment. Intersegment Reconciliation 2019 2018 2017 Intersegment revenues Communications $ 26 $ 13 $ - WarnerMedia 3,308 1,875 134 Latin America - - - Xandr 10 - - Total Intersegment Revenues 3,344 1,888 134 Consolidations 1,909 1,511 1,049 Eliminations and consolidations $ 5,253 $ 3,399 $ 1,183 At or for the years ended December 31, 2019 2018 Investments in Equity Method Investees Capital Expenditures Investments in Equity Method Investees Capital Expenditures Assets Assets Communications $ 521,252 $ - $ 17,410 $ 485,357 $ - $ 19,509 WarnerMedia 137,264 3,011 1,013 132,453 5,547 581 Latin America 20,606 650 757 18,148 677 745 Xandr 3,116 - 192 2,718 - 106 Corporate and eliminations ( 130,569) 34 263 ( 106,812) 21 310 Total $ 551,669 $ 3,695 $ 19,635 $ 531,864 $ 6,245 $ 21,251

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	Revenue Categories The following tables set forth reported revenue by category and by business unit: For the year ended December 31, 2019 Service Revenues Wireless Advanced Data Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 55,040 $ - $ - $ - $ - $ 291 $ - $ 15,725 $ 71,056 Entertainment Group - 8,403 2,573 30,438 - 1,672 2,032 8 45,126 Business Wireline - 12,926 9,180 - - - 3,286 785 26,177 WarnerMedia Turner - - - 7,736 481 4,566 339 - 13,122 Home Box Office - - - 5,814 925 - 10 - 6,749 Warner Bros. - - - 88 13,532 41 697 - 14,358 Eliminations and Other - - - 222 ( 1,058) 69 37 - ( 730) Latin America Vrio - - - 4,094 - - - - 4,094 Mexico 1,863 - - - - - - 1,006 2,869 Xandr - - - - - 2,022 - - 2,022 Corporate and Other 549 51 155 - - - 678 170 1,603 Eliminations and consolidations - - - - ( 3,249) ( 1,672) ( 332) - ( 5,253) Total Operating Revenues $ 57,452 $ 21,380 $ 11,908 $ 48,392 $ 10,631 $ 6,989 $ 6,747 $ 17,694 $ 181,193 For the year ended December 31, 2018 Service Revenues Wireless Advanced Data Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 54,062 $ - $ - $ - $ - $ 232 $ - $ 16,227 $ 70,521 Entertainment Group - 7,956 3,041 31,762 - 1,595 2,097 9 46,460 Business Wireline - 12,245 10,674 - - - 2,998 823 26,740 WarnerMedia Turner - - - 4,207 295 2,330 147 - 6,979 Home Box Office - - - 3,201 391 - 6 - 3,598 Warner Bros. - - - 47 8,216 53 387 - 8,703 Eliminations and Other - - - 74 ( 518) 78 27 - ( 339) Latin America Vrio - - - 4,784 - - - - 4,784 Mexico 1,701 - - - - - - 1,167 2,868 Xandr - - - - - 1,740 - - 1,740 Corporate and Other 638 52 36 - - - 1,190 185 2,101 Eliminations and consolidations - - - - ( 1,843) ( 1,595) 39 - ( 3,399) Total Operating Revenues $ 56,401 $ 20,253 $ 13,751 $ 44,075 $ 6,541 $ 4,433 $ 6,891 $ 18,411 $ 170,756
Capitalized Contract Cost [Table Text Block]	The following table presents the deferred customer contract acquisition and fulfillment costs included on our consolidated balance sheets at December 31: Consolidated Balance Sheets 2019 2018 Deferred Acquisition Costs Other current assets $ 2,462 $ 1,901 Other Assets 2,991 2,073 Total deferred customer contract acquisition costs $ 5,453 $ 3,974 Deferred Fulfillment Costs Other current assets $ 4,519 $ 4,090 Other Assets 6,439 7,450 Total deferred customer contract fulfillment costs $ 10,958 $ 11,540 The following table presents amortization of deferred customer contract acquisition and fulfillment cost, which are recorded in other cost of revenues in our consolidated statements of income, for the year ended December 31: Consolidated Statements of Income 2019 2018 Deferred acquisition cost amortization $ 2,174 $ 1,433 Deferred fulfillment cost amortization 4,947 4,039
Contract with Customer, Asset and Liability [Table Text Block]	The following table presents contract assets and liabilities on our consolidated balance sheets at December 31: Consolidated Balance Sheets 2019 2018 Contract assets $ 2,472 $ 1,896 Contract liabilities 6,999 6,856

Acquisitions, Dispositions An_2

Acquisitions, Dispositions And Other Adjustments (Tables)	12 Months Ended
	Dec. 31, 2019
Acquisitions, Dispositions And Other Adjustments
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table summarizes the fair values of the Time Warner assets acquired and liabilities assumed and related deferred income taxes as of the acquisition date: Assets acquired Cash $ 1,889 Accounts receivable 9,020 All other current assets 2,913 Noncurrent inventory and theatrical film and television production costs 5,591 Property, plant and equipment 4,693 Intangible assets subject to amortization Distribution network 18,040 Released television and film content 10,806 Trademarks and trade names 18,081 Other 10,300 Investments and other assets 9,438 Goodwill 38,801 Total assets acquired 129,572 Liabilities assumed Current liabilities, excluding current portion of long-term debt 8,294 Debt maturing within one year 4,471 Long-term debt 18,394 Other noncurrent liabilities 19,054 Total liabilities assumed 50,213 Net assets acquired 79,359 Noncontrolling interest ( 1) Aggregate value of consideration paid $ 79,358
Business Acquisition, Pro Forma Information [Table Text Block]	(Unaudited) Year Ended December 31, 2018 2017 Total operating revenues $ 183,651 $ 188,769 Net Income Attributable to AT&T 20,814 31,380 Basic Earnings Per Share Attributable to Common Stock $ 2.86 $ 4.30 Diluted Earnings Per Share Attributable to Common Stock $ 2.85 $ 4.26

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant And Equipment
Summary Of Property, Plant And Equipment [Table Text Block]	NOTE 7. PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment is summarized as follows at December 31: Lives (years) 2019 2018 Land - $ 2,651 $ 2,714 Buildings and improvements 2-44 38,924 38,013 Central office equipment 1 3-10 96,061 95,173 Cable, wiring and conduit 15-50 72,042 73,397 Satellites 14-17 2,489 2,961 Other equipment 3-20 94,951 93,782 Software 3-7 22,244 19,124 Under construction - 4,176 5,526 333,538 330,690 Accumulated depreciation and amortization 203,410 199,217 Property, plant and equipment - net $ 130,128 $ 131,473 1 Includes certain network software.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lease, Cost [Table Text Block]	The components of lease expense are as follows: 2019 Operating lease cost $ 5,684 Finance lease cost: Amortization of right-of-use assets $ 271 Interest on lease obligation 169 Total finance lease cost $ 440 The following tables set forth supplemental balance sheet information related to leases at December 31, 2019: Operating Leases Operating lease right-of-use assets $ 24,039 Accounts payable and accrued liabilities $ 3,451 Operating lease obligation 21,804 Total operating lease obligation $ 25,255 Finance Leases Property, plant and equipment, at cost $ 3,534 Accumulated depreciation and amortization ( 1,296) Property, plant and equipment, net $ 2,238 Current portion of long-term debt $ 162 Long-term debt 1,872 Total finance lease obligation $ 2,034 Weighted-Average Remaining Lease Term Operating leases 8.4 yrs Finance leases 10.3 yrs Weighted-Average Discount Rate Operating leases 4.2 % Finance leases 8.4 %
Schedule Of Maturities Of Operating And Finance Leases Liabilities [Table Text Block]	The following table provides the expected future minimum maturities of lease obligations: Operating Finance Leases Leases 2020 $ 4,723 $ 340 2021 4,349 305 2022 4,028 289 2023 3,611 274 2024 3,078 258 Thereafter 11,366 1,649 Total lease payments 31,155 3,115 Less: imputed interest ( 5,900) ( 1,081) Total $ 25,255 $ 2,034

Goodwill And Other Intangible_2

Goodwill And Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill And Other Intangible Assets
Summary Of Changes In Carrying Amount Of Goodwill, By Segment [Table Text Block]	2019 2018 Balance at Jan. 1 Acquisitions Dispositions, currency exchange and other Balance at Dec. 31 Balance at Jan. 1 Reallocation Acquisitions Dispositions, currency exchange and other Balance at Dec. 31 Communications $ 100,551 $ - $ ( 317) $ 100,234 $ 39,280 $ 61,075 $ 422 $ ( 226) $ 100,551 WarnerMedia 40,698 - 181 40,879 - 681 40,036 ( 19) 40,698 Latin America 3,718 - ( 56) 3,662 4,234 ( 32) - ( 484) 3,718 Xandr 1,403 66 ( 3) 1,466 - 211 1,220 ( 28) 1,403 Business Solutions - - - - 45,395 ( 45,395) - - - Consumer Mobility - - - - 16,540 ( 16,540) - - - Total $ 146,370 $ 66 $ ( 195) $ 146,241 $ 105,449 $ - $ 41,678 $ ( 757) $ 146,370
Schedule Of Amortized Intangible Assets [Table Text Block]	Our other intangible assets at December 31 are summarized as follows: 2019 2018 Other Intangible Assets Weighted-Average Life Gross Carrying Amount Accumulated Amortization Currency Translation Adjustment Gross Carrying Amount Accumulated Amortization Currency Translation Adjustment Amortized intangible assets: Wireless licenses 24.5 years $ 2,981 $ 156 $ ( 243) $ - $ - $ - Trademarks and trade names 37.3 years 18,359 853 ( 6) 18,371 293 ( 7) Distribution network 10.0 years 18,138 2,793 - 18,040 971 - Released television and film content 16.4 years 10,941 4,974 - 10,814 2,988 - Customer lists and relationships 9.1 years 20,304 14,773 ( 281) 20,516 12,451 ( 314) Other 20.4 years 11,427 1,843 ( 3) 11,624 907 ( 25) Total 21.5 years $ 82,150 $ 25,392 $ ( 533) $ 79,365 $ 17,610 $ ( 346) Indefinite-lived intangible assets not subject to amortization, net of currency translation adjustment: Licenses: Wireless licenses $ 83,623 $ 84,442 Orbital slots 11,702 11,702 Trade names 6,067 6,274 Total $ 101,392 $ 102,418
Schedule Of Indefinite-Life Intangible Assets Not Subject To Amortization [Table Text Block]	Our other intangible assets at December 31 are summarized as follows: 2019 2018 Other Intangible Assets Weighted-Average Life Gross Carrying Amount Accumulated Amortization Currency Translation Adjustment Gross Carrying Amount Accumulated Amortization Currency Translation Adjustment Amortized intangible assets: Wireless licenses 24.5 years $ 2,981 $ 156 $ ( 243) $ - $ - $ - Trademarks and trade names 37.3 years 18,359 853 ( 6) 18,371 293 ( 7) Distribution network 10.0 years 18,138 2,793 - 18,040 971 - Released television and film content 16.4 years 10,941 4,974 - 10,814 2,988 - Customer lists and relationships 9.1 years 20,304 14,773 ( 281) 20,516 12,451 ( 314) Other 20.4 years 11,427 1,843 ( 3) 11,624 907 ( 25) Total 21.5 years $ 82,150 $ 25,392 $ ( 533) $ 79,365 $ 17,610 $ ( 346) Indefinite-lived intangible assets not subject to amortization, net of currency translation adjustment: Licenses: Wireless licenses $ 83,623 $ 84,442 Orbital slots 11,702 11,702 Trade names 6,067 6,274 Total $ 101,392 $ 102,418

Equity Method Investments (Tabl

Equity Method Investments (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments
Reconciliation Of Investments In Equity Affiliates [Table Text Block]	The following table is a reconciliation of our investments in equity affiliates as presented on our consolidated balance sheets: 2019 2018 Beginning of year $ 6,245 $ 1,560 Additional investments 448 237 Disposition of Hudson Yards ( 1,681) - Disposition of Hulu ( 689) - Disposition of Game Show Network ( 288) - Time Warner investments acquired - 4,912 Acquisition of remaining interest in Otter Media - ( 166) Equity in net income (loss) of affiliates 6 (48) Dividends and distributions received ( 301) ( 243) Currency translation adjustments ( 10) ( 14) Other adjustments ( 35) 7 End of year $ 3,695 $ 6,245

Inventories and Theatrical Fi_2

Inventories and Theatrical Film and Television Production Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories and Theatrical Film and Television Production Costs [Table Text Block]	The following table summarizes inventories and theatrical film and television production costs as of December 31: 2019 2018 Inventories: Programming costs, less amortization 1 $ 4,599 $ 4,097 Other inventory, primarily DVD and Blu-ray Discs 96 146 Total inventories 4,695 4,243 Less: current portion of inventory ( 96) ( 2,420) Total noncurrent inventories 4,599 1,823 Theatrical film production costs: 2 Released, less amortization 392 451 Completed and not released 437 435 In production 1,475 866 Development and pre-production 171 159 Television production costs: 2 Released, less amortization 1,752 965 Completed and not released 1,344 1,087 In production 2,207 1,898 Development and pre-production 57 29 Total theatrical film and television production costs 7,835 5,890 Total noncurrent inventories and theatrical film and television production costs $ 12,434 $ 7,713 1 Includes the costs of certain programming rights, primarily sports, for which payments have been made prior to the related rights being received. 2 Does not include $ 5,967, and $ 7,826 of acquired film and television library intangible assets as of December 31, 2019, and 2018, respectively, which are included in “Other Intangible Assets – Net” on our consolidated balance sheet.

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure
Summary Of Long-Term Debt Of AT&T And Its Subsidiaries [Table Text Block]	NOTE 12. DEBT Long-term debt of AT&T and its subsidiaries, including interest rates and maturities, is summarized as follows at December 31: 2019 2018 Notes and debentures Interest Rates Maturities 1 1.80% - 2.99% 2019 - 2039 $ 17,404 $ 14,404 3.00% - 4.99% 2019 - 2050 102,595 104,291 5.00% - 6.99% 2019 - 2095 34,513 37,175 7.00% - 9.15% 2019 - 2097 5,050 5,976 Credit agreement borrowings 4,969 12,618 Other - 89 Fair value of interest rate swaps recorded in debt 26 ( 32) 164,557 174,521 Unamortized (discount) premium - net ( 2,996) ( 2,526) Unamortized issuance costs ( 452) ( 466) Total notes and debentures 161,109 171,529 Finance lease obligations 2,034 1,911 Total long-term debt, including current maturities 163,143 173,440 Current maturities of long-term debt ( 11,834) ( 7,190) Total long-term debt $ 151,309 $ 166,250 1 Maturities assume putable debt is redeemed by the holders at the next opportunity.
Debt Maturing Within One Year [Table Text Block]	Debt maturing within one year consisted of the following at December 31: 2019 2018 Current maturities of long-term debt $ 11,834 $ 7,190 Commercial paper - 3,048 Bank borrowings 1 4 4 Other - 13 Total $ 11,838 $ 10,255 1 Outstanding balance of short-term credit facility of a foreign subsidiary.
Long-Term Debt - Scheduled Repayments [Table Text Block]	2020 2021 2022 2023 2024 Thereafter Debt repayments 1 $ 12,149 $ 11,036 $ 11,189 $ 10,037 $ 11,225 $ 112,429 Weighted-average interest rate 2.9 % 3.8 % 3.5 % 3.5 % 3.6 % 4.8 % 1 Debt repayments assume putable debt is redeemed by the holders at the next opportunity.

Fair Value Measurements And D_3

Fair Value Measurements And Disclosure (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements And Disclosure
Long-Term Debt And Other Financial Instruments [Table Text Block]	Long-Term Debt and Other Financial Instruments The carrying amounts and estimated fair values of our long-term debt, including current maturities, and other financial instruments, are summarized as follows: December 31, 2019 December 31, 2018 Carrying Fair Carrying Fair Amount Value Amount Value Notes and debentures 1 $ 161,109 $ 182,124 $ 171,529 $ 172,287 Commercial paper - - 3,048 3,048 Bank borrowings 4 4 4 4 Investment securities 2 3,723 3,723 3,409 3,409 1 Includes credit agreement borrowings. 2 Excludes investments accounted for under the equity method.
Fair Value Leveling [Table Text Block]	December 31, 2019 Level 1 Level 2 Level 3 Total Equity Securities Domestic equities $ 844 $ - $ - $ 844 International equities 183 - - 183 Fixed income equities 229 - - 229 Available-for-Sale Debt Securities - 1,444 - 1,444 Asset Derivatives Interest rate swaps - 2 - 2 Cross-currency swaps - 172 - 172 Interest rate locks - 11 - 11 Foreign exchange contracts - 89 - 89 Liability Derivatives Cross-currency swaps - ( 3,187) - ( 3,187) Interest rate locks - ( 95) - ( 95) December 31, 2018 Level 1 Level 2 Level 3 Total Equity Securities Domestic equities $ 1,061 $ - $ - $ 1,061 International equities 256 - - 256 Fixed income equities 172 - - 172 Available-for-Sale Debt Securities - 870 - 870 Asset Derivatives Cross-currency swaps - 472 - 472 Foreign exchange contracts - 87 - 87 Liability Derivatives Interest rate swaps - ( 39) - ( 39) Cross-currency swaps - ( 2,563) - ( 2,563) Foreign exchange contracts - ( 2) - ( 2)
Unrealized Gain (Loss) on Investments [Table Text Block]	The components comprising total gains and losses in the period on equity securities are as follows: For the years ended December 31, 2019 2018 2017 Total gains (losses) recognized on equity securities $ 301 $ ( 130) $ 326 Gains (losses) recognized on equity securities sold 100 ( 10) 47 Unrealized gains (losses) recognized on equity securities held at end of period $ 201 $ ( 120) $ 279
Notional Amount Of Outstanding Derivative Positions [Table Text Block]	Following are the notional amounts of our outstanding derivative positions at December 31: 2019 2018 Interest rate swaps $ 853 $ 3,483 Cross-currency swaps 42,325 42,192 Interest rate locks 3,500 - Foreign exchange contracts 269 2,094 Total $ 46,947 $ 47,769
Effect Of Derivatives On The Consolidated Statements Of Income [Table Text Block]	Following are the related hedged items affecting our financial position and performance: Effect of Derivatives on the Consolidated Statements of Income Fair Value Hedging Relationships For the years ended December 31, 2019 2018 2017 Interest rate swaps (Interest expense): Gain (Loss) on interest rate swaps $ 58 $ ( 12) $ ( 68) Gain (Loss) on long-term debt ( 58) 12 68 The net swap settlements that accrued and settled in the periods above were included in interest expense. Cash Flow Hedging Relationships For the years ended December 31, 2019 2018 2017 Cross-currency swaps: Gain (Loss) recognized in accumulated OCI $ ( 1,066) $ ( 825) $ 571 Foreign exchange contracts: Gain (Loss) recognized in accumulated OCI 10 51 - Other income (expense) - net reclassified from accumulated OCI into income 6 39 - Interest rate locks: Gain (Loss) recognized in accumulated OCI ( 84) - - Interest income (expense) reclassified from accumulated OCI into income ( 63) ( 58) ( 60)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Taxes [Abstract]
Components Of Deferred Tax Liabilities (Assets) [Table Text Block]	Significant components of our deferred tax liabilities (assets) are as follows at December 31: 2019 2018 Depreciation and amortization $ 44,896 $ 43,105 Licenses and nonamortizable intangibles 17,355 17,561 Employee benefits ( 5,143) ( 5,366) Deferred fulfillment costs 3,050 2,679 Net operating loss and other carryforwards ( 7,301) ( 6,470) Other – net 1,536 1,651 Subtotal 54,393 53,160 Deferred tax assets valuation allowance 4,941 4,588 Net deferred tax liabilities $ 59,334 $ 57,748 Noncurrent deferred tax liabilities $ 59,502 $ 57,859 Less: Noncurrent deferred tax assets ( 168) ( 111) Net deferred tax liabilities $ 59,334 $ 57,748
Changes In Unrecognized Tax Benefits Balance For Federal, State, And Foreign Tax [Table Text Block]	Federal, State and Foreign Tax 2019 2018 Balance at beginning of year $ 10,358 $ 7,648 Increases for tax positions related to the current year 903 336 Increases for tax positions related to prior years 1,106 2,615 Decreases for tax positions related to prior years ( 1,283) ( 394) Lapse of statute of limitations ( 32) ( 52) Settlements ( 283) ( 664) Current year acquisitions 205 872 Foreign currency effects 5 ( 3) Balance at end of year 10,979 10,358 Accrued interest and penalties 2,708 2,588 Gross unrecognized income tax benefits 13,687 12,946 Less: Deferred federal and state income tax benefits ( 886) ( 811) Less: Tax attributable to timing items included above ( 4,320) ( 3,430) Less: UTBs included above that relate to acquired entities that would impact goodwill if recognized - ( 918) Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year $ 8,481 $ 7,787
Components Of Income Tax Expense [Table Text Block]	The components of income tax (benefit) expense are as follows: 2019 2018 2017 Federal: Current $ 584 $ 3,258 $ 682 Deferred 1,656 277 ( 17,970) 2,240 3,535 ( 17,288) State and local: Current 603 513 79 Deferred 144 473 1,041 747 986 1,120 Foreign: Current 605 539 471 Deferred ( 99) ( 140) 989 506 399 1,460 Total $ 3,493 $ 4,920 $ ( 14,708)
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]	“Income Before Income Taxes” in the Consolidated Statements of Income included the following components for the years ended December 31: 2019 2018 2017 U.S. income before income taxes $ 18,301 $ 25,379 $ 16,438 Foreign income (loss) before income taxes 167 ( 506) ( 1,299) Total $ 18,468 $ 24,873 $ 15,139
Reconciliation Of Income Tax Expense Based On Federal Statutory Rate To Amount Per Effective Tax Rate [Table Text Block]	2019 2018 2017 Taxes computed at federal statutory rate $ 3,878 $ 5,223 $ 5,299 Increases (decreases) in income taxes resulting from: State and local income taxes – net of federal income tax benefit 611 738 509 Enactment date and measurement period adjustments from the Act - ( 718) ( 20,271) Tax on foreign investments ( 115) ( 466) 73 Noncontrolling interest ( 230) ( 121) ( 133) Other – net ( 651) 264 ( 185) Total $ 3,493 $ 4,920 $ ( 14,708) Effective Tax Rate 18.9 % 19.8 % ( 97.2) %

Pension And Postretirement Be_3

Pension And Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2019
Pension And Postretirement Benefits
Schedule Of Plan Obligations In Excess Of Plan Assets [Table Text Block]	The following table presents the change in the projected benefit obligation for the years ended December 31: Pension Benefits Postretirement Benefits 2019 2018 2019 2018 Benefit obligation at beginning of year $ 55,439 $ 59,294 $ 19,378 $ 24,059 Service cost - benefits earned during the period 1,019 1,116 71 109 Interest cost on projected benefit obligation 1,960 2,092 675 778 Amendments - 50 ( 4,590) ( 1,145) Actuarial (gain) loss 7,734 ( 5,046) 2,050 ( 2,815) Special termination benefits 81 1 - 1 Benefits paid ( 6,356) ( 4,632) ( 1,543) ( 1,680) Acquisitions - 2,559 - 71 Plan transfers ( 4) 5 - - Benefit obligation at end of year $ 59,873 $ 55,439 $ 16,041 $ 19,378 The following table presents the change in the fair value of plan assets for the years ended December 31 and the plans’ funded status at December 31: Pension Benefits Postretirement Benefits 2019 2018 2019 2018 Fair value of plan assets at beginning of year $ 51,681 $ 45,463 $ 4,277 $ 5,973 Actual return on plan assets 8,207 ( 1,044) 609 ( 218) Benefits paid 1 ( 6,356) ( 4,632) ( 941) ( 1,503) Contributions 2 9,307 200 25 Acquisitions - 2,582 - - Plan transfers ( 4) 5 - - Fair value of plan assets at end of year 53,530 51,681 4,145 4,277 Unfunded status at end of year 2 $ ( 6,343) $ ( 3,758) $ ( 11,896) $ ( 15,101) 1 At our discretion, certain postretirement benefits may be paid from AT&T cash accounts, which does not reduce Voluntary Employee Benefit Association (VEBA) assets. Future benefit payments may be made from VEBA trusts and thus reduce those asset balances. 2 Funded status is not indicative of our ability to pay ongoing pension benefits or of our obligation to fund retirement trusts. Required pension funding is determined in accordance with the Employee Retirement Income Security Act of 1974, as amended (ERISA) and applicable regulations. Amounts recognized on our consolidated balance sheets at December 31 are listed below: Pension Benefits Postretirement Benefits 2019 2018 2019 2018 Current portion of employee benefit obligation 1 $ - $ - $ ( 1,365) $ ( 1,464) Employee benefit obligation 2 ( 6,343) ( 3,758) ( 10,531) ( 13,637) Net amount recognized $ ( 6,343) $ ( 3,758) $ ( 11,896) $ ( 15,101) 1 Included in “Accounts payable and accrued liabilities.” 2 Included in “Postemployment benefit obligation.”
Schedule Of Defined Benefit Plan And Postretirement Benefits Disclosure [Table Text Block]	The following table presents the components of net periodic benefit cost (credit): Pension Benefits Postretirement Benefits 2019 2018 2017 2019 2018 2017 Service cost – benefits earned during the period $ 1,019 $ 1,116 $ 1,128 $ 71 $ 109 $ 138 Interest cost on projected benefit obligation 1,960 2,092 1,936 675 778 809 Expected return on assets ( 3,561) ( 3,190) ( 3,134) ( 227) ( 304) ( 319) Amortization of prior service credit ( 113) ( 115) ( 123) ( 1,820) ( 1,635) ( 1,466) Actuarial (gain) loss 3,088 ( 812) 844 1,670 ( 2,290) 342 Net pension and postretirement cost (credit) $ 2,393 $ ( 909) $ 651 $ 369 $ ( 3,342) $ ( 496) Other Changes in Benefit Obligations Recognized in Other Comprehensive Income The following table presents the after-tax changes in benefit obligations recognized in OCI and the after-tax prior service credits that were amortized from OCI into net periodic benefit costs: Pension Benefits Postretirement Benefits 2019 2018 2017 2019 2018 2017 Balance at beginning of year $ 447 $ 571 $ 575 $ 6,086 $ 6,456 $ 5,089 Prior service (cost) credit - ( 37) ( 30) 3,457 864 1,120 Amortization of prior service credit ( 86) ( 87) ( 76) ( 1,372) ( 1,234) ( 907) Total recognized in other comprehensive (income) loss ( 86) ( 124) ( 106) 2,085 ( 370) 213 Adoption of ASU 2018-02 - - 102 - - 1,154 Balance at end of year $ 361 $ 447 $ 571 $ 8,171 $ 6,086 $ 6,456
Schedule Of Assumptions In Determining The Projected Benefit Obligation And Net Pension And Postretirement Benefit Cost [Table Text Block]	Assumptions In determining the projected benefit obligation and the net pension and postretirement benefit cost, we used the following significant weighted-average assumptions: Pension Benefits Postretirement Benefits 2019 2018 2017 2019 2018 2017 Weighted-average discount rate for determining benefit obligation at December 31 3.40 % 4.50 % 3.80 % 3.20 % 4.40 % 3.70 % Discount rate in effect for determining service cost 1,2 4.10 % 4.20 % 4.60 % 4.40 % 4.30 % 4.60 % Discount rate in effect for determining interest cost 1,2 3.50 % 3.80 % 3.60 % 3.70 % 3.60 % 3.40 % Weighted-average interest crediting rate for cash balance pension programs 3 3.30 % 3.70 % 3.50 % - % - % - % Long-term rate of return on plan assets 7.00 % 7.00 % 7.75 % 5.75 % 5.75 % 5.75 % Composite rate of compensation increase for determining benefit obligation 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % Composite rate of compensation increase for determining net cost (benefit) 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % 3.00 % 1 Weighted-average discount rate for pension benefits in effect from January 1, 2019 through March 31, 2019 was 4.60% for service cost and 4.20% for interest cost, from April 1, 2019 through June 30, 2019 was 4.30% for service cost and 3.70% for interest cost, from July 1, 2019 through September 30, 2019 was 3.90% for service cost and 3.20% for interest cost, and, from October 1, 2019 through December 31, 2019 was 3.50% for service cost and 3.00% for interest cost. 2 Weighted-average discount rate for postretirement benefits in effect from January 1, 2019 through October 1, 2019 was 4.70% for service cost and 4.00% for interest cost, and, from October 2, 2019 through December 31, 2019 was 3.40% for service cost and 2.70% for interest cost. 3 Weighted-average interest crediting rates for cash balance pension programs relate only to the cash balance portion of total pension benefits. A 0.50% increase in the weighted-average interest crediting rate would increase the pension benefit obligation by $ 130.
Schedule Of Defined Benefit Plan Targeted And Actual Plan Asset Allocations [Table Text Block]	The plans’ weighted-average asset targets and actual allocations as a percentage of plan assets, including the notional exposure of future contracts by asset categories at December 31, are as follows: Pension Assets Postretirement (VEBA) Assets Target 2019 2018 Target 2019 2018 Equity securities: Domestic 15 % - 25 % 17 % 16 % 15 % - 25 % 20 % 25 % International 7 % - 17 % 12 12 8 % - 18 % 12 18 Fixed income securities 29 % - 39 % 35 37 47 % - 57 % 52 39 Real assets 4 % - 14 % 9 9 - % - 6 % 1 1 Private equity 2 % - 12 % 8 8 - % - 7 % 2 2 Preferred interest 13 % - 23 % 17 18 - % - - % - - Other - % - 5 % 2 - 9 % - 19 % 13 15 Total 100 % 100 % 100 % 100 %
Schedule Of Fair Value Of Pension And Postretirement Assets And Liabilities By Level [Table Text Block]	Pension Assets and Liabilities at Fair Value as of December 31, 2019 Level 1 Level 2 Level 3 Total Non-interest bearing cash $ 85 $ - $ - $ 85 Interest bearing cash 529 - - 529 Foreign currency contracts - 5 - 5 Equity securities: Domestic equities 8,068 - 4 8,072 International equities 3,929 11 6 3,946 Preferred interest - - 8,806 8,806 Fixed income securities: Corporate bonds and other investments - 10,469 4 10,473 Government and municipal bonds 49 6,123 - 6,172 Mortgage-backed securities - 522 2 524 Real estate and real assets - - 2,817 2,817 Securities lending collateral 103 1,658 - 1,761 Receivable for variation margin 5 - - 5 Assets at fair value 12,768 18,788 11,639 43,195 Investments sold short and other liabilities at fair value ( 513) ( 2) - ( 515) Total plan net assets at fair value $ 12,255 $ 18,786 $ 11,639 $ 42,680 Assets held at net asset value practical expedient Private equity funds 4,544 Real estate funds 2,062 Commingled funds 5,710 Total assets held at net asset value practical expedient 12,316 Other assets (liabilities) 1 ( 1,466) Total Plan Net Assets $ 53,530 1 Other assets (liabilities) include amounts receivable, accounts payable and net adjustment for securities lending payable. Postretirement Assets and Liabilities at Fair Value as of December 31, 2019 Level 1 Level 2 Level 3 Total Interest bearing cash $ 248 $ 301 $ - $ 549 Equity securities: Domestic equities 438 - - 438 International equities 265 - - 265 Fixed income securities: Corporate bonds and other investments 7 492 31 530 Government and municipal bonds 6 182 1 189 Mortgage-backed securities - 294 - 294 Securities lending collateral - 36 - 36 Assets at fair value 964 1,305 32 2,301 Securities lending payable and other liabilities - ( 36) - ( 36) Total plan net assets at fair value $ 964 $ 1,269 $ 32 $ 2,265 Assets held at net asset value practical expedient Private equity funds 66 Real estate funds 27 Commingled funds 1,797 Total assets held at net asset value practical expedient 1,890 Other assets (liabilities) 1 ( 10) Total Plan Net Assets $ 4,145 1 Other assets (liabilities) include amounts receivable and accounts payable. Pension Assets and Liabilities at Fair Value as of December 31, 2018 Level 1 Level 2 Level 3 Total Non-interest bearing cash $ 52 $ - $ - $ 52 Interest bearing cash 167 41 - 208 Foreign currency contracts - 5 - 5 Equity securities: Domestic equities 6,912 - 1 6,913 International equities 3,594 8 - 3,602 Preferred interest - - 8,749 8,749 Fixed income securities: Corporate bonds and other investments - 10,719 4 10,723 Government and municipal bonds 51 6,170 - 6,221 Mortgage-backed securities - 382 - 382 Real estate and real assets - - 2,579 2,579 Securities lending collateral 12 1,466 - 1,478 Purchased options, futures, and swaps - 3 - 3 Receivable for variation margin 19 - - 19 Assets at fair value 10,807 18,794 11,333 40,934 Investments sold short and other liabilities at fair value ( 657) ( 6) - ( 663) Total plan net assets at fair value $ 10,150 $ 18,788 $ 11,333 $ 40,271 Assets held at net asset value practical expedient Private equity funds 4,384 Real estate funds 2,162 Commingled funds 5,740 Total assets held at net asset value practical expedient 12,286 Other assets (liabilities) 1 ( 876) Total Plan Net Assets $ 51,681 1 Other assets (liabilities) include amounts receivable, accounts payable and net adjustment for securities lending payable. Postretirement Assets and Liabilities at Fair Value as of December 31, 2018 Level 1 Level 2 Level 3 Total Interest bearing cash $ 45 $ 624 $ - $ 669 Equity securities: Domestic equities 745 8 - 753 International equities 541 - 1 542 Fixed income securities: Corporate bonds and other investments 7 602 11 620 Government and municipal bonds 2 377 1 380 Mortgage-backed securities - 283 - 283 Securities lending collateral - 63 - 63 Assets at fair value 1,340 1,957 13 3,310 Securities lending payable and other liabilities - ( 74) - ( 74) Total plan net assets at fair value $ 1,340 $ 1,883 $ 13 $ 3,236 Assets held at net asset value practical expedient Private equity funds 79 Real estate funds 36 Commingled funds 973 Total assets held at net asset value practical expedient 1,088 Other assets (liabilities) 1 ( 47) Total Plan Net Assets $ 4,277 1 Other assets (liabilities) include amounts receivable and accounts payable.
Summary of Changes In The Fair Value Of The Level 3 Pension And Postretirement Assets [Table Text Block]	The tables below set forth a summary of changes in the fair value of the Level 3 pension and postretirement assets for the year ended December 31, 2019: Pension Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 8,750 $ 4 $ 2,579 $ 11,333 Realized gains (losses) - - 64 64 Unrealized gains (losses) 58 - 45 103 Transfers in 8 5 134 147 Transfers out - ( 6) - ( 6) Purchases - 7 228 235 Sales - ( 4) ( 233) ( 237) Balance at end of year $ 8,816 $ 6 $ 2,817 $ 11,639 Postretirement Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 1 $ 12 $ - $ 13 Transfers in - 28 - 28 Transfers out - ( 1) - ( 1) Sales ( 1) ( 7) - ( 8) Balance at end of year $ - $ 32 $ - $ 32 The tables below set forth a summary of changes in the fair value of the Level 3 pension and postretirement assets for the year ended December 31, 2018: Pension Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 4 $ 2 $ 2,287 $ 2,293 Realized gains (losses) - - 120 120 Unrealized gains (losses) ( 408) ( 1) 170 ( 239) Transfers in 9,158 1 266 9,425 Transfers out ( 4) ( 1) - ( 5) Purchases - 8 85 93 Sales - ( 5) ( 349) ( 354) Balance at end of year $ 8,750 $ 4 $ 2,579 $ 11,333 Postretirement Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ - $ 5 $ - $ 5 Transfers in 1 8 - 9 Transfers out - ( 1) - ( 1) Purchases - 1 - 1 Sales - ( 1) - ( 1) Balance at end of year $ 1 $ 12 $ - $ 13
Estimated Future Benefit Payments [Table Text Block]	Pension Benefits Postretirement Benefits 2020 $ 5,540 $ 1,539 2021 4,471 1,441 2022 4,362 1,343 2023 4,272 1,258 2024 4,174 1,015 Years 2025 - 2029 19,965 4,307

Share-Based Payment (Tables)

Share-Based Payment (Tables)	12 Months Ended
	Dec. 31, 2019
Share-Based Payment
Compensation Cost [Table Text Block]	Our consolidated statements of income include the compensation cost recognized for those plans as operating expenses, as well as the associated tax benefits, which are reflected in the table below: 2019 2018 2017 Performance stock units $ 544 $ 301 $ 395 Restricted stock and stock units 273 153 90 Other nonvested stock units 7 4 ( 5) Stock options ( 5) 5 - Total $ 819 $ 463 $ 480 Income tax benefit $ 202 $ 114 $ 184
Status Of Nonvested Stock Units Activity And Changes During Year [Table Text Block]	A summary of the status of our nonvested stock units as of December 31, 2019, and changes during the year then ended is presented as follows (shares in millions): Nonvested Stock Units Shares Weighted-Average Grant-Date Fair Value Nonvested at January 1, 2019 39 $ 38.44 Granted 27 31.18 Vested ( 21) 39.03 Forfeited ( 3) 34.26 Nonvested at December 31, 2019 42 $ 33.80

Sale of Receivables (Tables)

Sale of Receivables (Tables)	12 Months Ended
	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance Receivables [Table Text Block]	Our equipment installment and WarnerMedia programs are discussed in detail below. The following table sets forth a summary of the receivables and accounts being serviced at December 31: 2019 2018 Equipment Equipment Installment WarnerMedia Installment WarnerMedia Gross receivables: $ 4,576 $ 3,324 $ 5,994 $ - Balance sheet classification Accounts receivable Notes receivable 2,467 - 3,457 - Trade receivables 477 2,809 438 - Other Assets Noncurrent notes and trade receivables 1,632 515 2,099 - Outstanding portfolio of receivables derecognized from our consolidated balance sheets 9,713 4,300 9,065 - Cash proceeds received, net of remittances 1 7,211 4,300 6,508 - 1 Represents amounts to which financial institutions remain entitled, excluding the deferred purchase price. The following table sets forth a summary of equipment installment receivables sold: 2019 2018 2017 Gross receivables sold $ 9,921 $ 9,391 $ 8,058 Net receivables sold 1 9,483 8,871 7,388 Cash proceeds received 8,189 7,488 5,623 Deferred purchase price recorded 1,451 1,578 2,077 Guarantee obligation recorded 341 361 215 1 Receivables net of allowance, imputed interest and equipment trade-in right guarantees.
Transfer of Financial Assets Accounted for as Sales [Table Text Block]	The following table sets forth a summary of WarnerMedia receivables sold: 2019 2018 2017 Gross receivables sold/cash proceeds received 1 $ 11,989 $ - $ - Collections reinvested under revolving agreement 7,689 - - Net cash proceeds received (remitted) $ 4,300 $ - $ - Net receivables sold 2 $ 11,604 $ - $ - Obligations recorded 530 - - 1 Includes initial sale of receivables of $ 4,300 for the year ended December 31, 2019. 2 Receivables net of allowance, return and incentive reserves and imputed interest.
Deferred Purchase Price [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance Receivables [Table Text Block]	The following table presents the previously transferred equipment installment receivables, which we repurchased in exchange for the associated deferred purchase price: 2019 2018 2017 Fair value of repurchased receivables $ 1,418 $ 1,480 $ 1,699 Carrying value of deferred purchase price 1,350 1,393 1,524 Gain on repurchases 1 $ 68 $ 87 $ 175 1 These gains are included in “Selling, general and administrative” in the consolidated statements of income.

Additional Financial Informat_2

Additional Financial Information (Tables)	12 Months Ended
	Dec. 31, 2019
Additional Financial Information [Abstract]
Consolidated Balance Sheets [Table Text Block]	NOTE 22. ADDITIONAL FINANCIAL INFORMATION December 31, Consolidated Balance Sheets 2019 2018 Accounts payable and accrued liabilities: Accounts payable $ 29,640 $ 27,018 Accrued payroll and commissions 3,126 3,379 Current portion of employee benefit obligation 1,528 1,464 Accrued interest 2,498 2,557 Other 9,164 8,766 Total accounts payable and accrued liabilities $ 45,956 $ 43,184
Consolidated Statements Of Income [Table Text Block]	Consolidated Statements of Income 2019 2018 2017 Advertising expense $ 6,121 $ 5,100 $ 3,772 Interest expense incurred $ 8,622 $ 8,450 $ 7,203 Capitalized interest ( 200) ( 493) ( 903) Total interest expense $ 8,422 $ 7,957 $ 6,300
Consolidated Statements Of Cash Flows [Table Text Block]	December 31, Cash and Cash Equivalents and Restricted Cash 2019 2018 2017 2016 Cash and cash equivalents $ 12,130 $ 5,204 $ 50,498 $ 5,788 Restricted cash in Other current assets 69 61 6 7 Restricted cash in Other Assets 96 135 428 140 Cash and cash equivalents and restricted cash $ 12,295 $ 5,400 $ 50,932 $ 5,935 The following table summarizes cash paid during the periods for interest and income taxes: Consolidated Statements of Cash Flows 2019 2018 2017 Cash paid (received) during the year for: Interest $ 8,693 $ 8,818 $ 6,622 Income taxes, net of refunds 1,421 ( 354) 2,006 The following table provides supplemental disclosures for the statement of cash flows related to operating leases: 2019 Cash Flows from Operating Activities Cash paid for amounts included in lease obligations: Operating cash flows from operating leases $ 4,583 Supplemental Lease Cash Flow Disclosures Operating lease right-of-use assets obtained in exchange for new operating lease obligations 7,818

Quarterly Financial Informati_2

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information (Unaudited)
Quarterly Financial Results [Table Text Block]	2019 Calendar Quarter First 1 Second 1 Third 1 Fourth 1,2 Annual Total Operating Revenues $ 44,827 $ 44,957 $ 44,588 $ 46,821 $ 181,193 Operating Income 7,233 7,500 7,901 5,321 27,955 Net Income 4,348 3,974 3,949 2,704 14,975 Net Income Attributable to AT&T 4,096 3,713 3,700 2,394 13,903 Basic Earnings Per Share Attributable to Common Stock 3 $ 0.56 $ 0.51 $ 0.50 $ 0.33 $ 1.90 Diluted Earnings Per Share Attributable to Common Stock 3 $ 0.56 $ 0.51 $ 0.50 $ 0.33 $ 1.89 Stock Price High $ 31.64 $ 33.55 $ 38.75 $ 39.70 Low 28.30 30.05 31.52 36.40 Close 31.36 33.51 37.84 39.08 1 Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15). 2 Includes an asset abandonment charge (Note 7). 3 Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year. 2018 Calendar Quarter First 1 Second 1 Third Fourth 1 Annual Total Operating Revenues $ 38,038 $ 38,986 $ 45,739 $ 47,993 $ 170,756 Operating Income 6,201 6,466 7,269 6,160 26,096 Net Income 4,759 5,248 4,816 5,130 19,953 Net Income Attributable to AT&T 4,662 5,132 4,718 4,858 19,370 Basic Earnings Per Share Attributable to Common Stock 2 $ 0.75 $ 0.81 $ 0.65 $ 0.66 $ 2.85 Diluted Earnings Per Share Attributable to Common Stock 2 $ 0.75 $ 0.81 $ 0.65 $ 0.66 $ 2.85 Stock Price High $ 39.29 $ 36.39 $ 34.28 $ 34.30 Low 34.44 31.17 30.13 26.80 Close 35.65 32.11 33.58 28.54 1 Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15). 2 Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year.

Valuation And Qualifying Acco_2

Valuation And Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2019
Valuation And Qualifying Accounts
Valuation And Qualifying Accounts [Table Text Block]	SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS Allowance for Doubtful Accounts COL. A COL. B COL. C COL. D COL. E Additions (1) (2) (3) Balance at Charged to Charged to Beginning of Costs and Other Balance at End Period Expenses (a) Accounts (b) Acquisitions (c) Deductions (d) of Period Year 2019 $ 907 2,575 - - 2,247 $ 1,235 Year 2018 $ 663 1,791 - 179 1,726 $ 907 Year 2017 $ 661 1,642 - - 1,640 $ 663 (a) Includes amounts previously written off which were credited directly to this account when recovered. Excludes direct charges and credits to expense for nontrade receivables in the consolidated statements of income. (b) Includes amounts related to long-distance carrier receivables which were billed by AT&T. (c) Acqusition of Time Warner in 2018. (d) Amounts written off as uncollectible, or related to divested entities. SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS Allowance for Deferred Tax Assets COL. A COL. B COL. C COL. D COL. E Additions (1) (2) (3) Balance at Charged to Charged to Beginning of Costs and Other Acquisitions Deductions Balance at End Period Expenses Accounts (a) (b) (c) of Period Year 2019 $ 4,588 ( 18) 371 - - $ 4,941 Year 2018 $ 4,640 ( 210) ( 53) 211 - $ 4,588 Year 2017 $ 2,283 2,376 ( 19) - - $ 4,640 (a) Includes current year reclassifications from other balance sheet accounts. (b) Acquisition of Time Warner in 2018. (c) Reductions to valuation allowances related to deferred tax assets.

Summary Of Significant Accoun_3

Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions

1 Months Ended

3 Months Ended

12 Months Ended

Jun. 30, 2018

Dec. 31, 2019

Sep. 30, 2019

[4]

Jun. 30, 2019

[4]

Mar. 31, 2019

[4]

Dec. 31, 2018

Sep. 30, 2018

[4]

Jun. 30, 2018

[4]

Mar. 31, 2018

[4]

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Jan. 01, 2019

Jan. 01, 2018

Jan. 01, 2017

[2]

Dec. 31, 2016

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Operating lease liability

$ 25,255

$ 25,255

Operating Lease, Right-of-Use Asset

24,039

$ 0

24,039

$ 0

Retained earnings

57,936

58,753

57,936

58,753

Other current assets

18,364

17,704

18,364

17,704

Contract asset

2,472

1,896

2,472

1,896

Deferred income tax liabilities

59,334

57,748

59,334

57,748

Noncontrolling interest

17,713

9,795

17,713

9,795

Cumulative effect of accounting changes

$ (658)

[1]

$ 1,529

Income tax effects reclassed to retained earnings

[3]

0

Net Income attributable to AT&T - Financial Effect (in millions)

2,394

[4],[5]

$ 3,700

$ 3,713

$ 4,096

4,858

[4]

$ 4,718

$ 5,132

$ 4,662

$ 4,718

$ 5,132

$ 4,662

13,903

19,370

$ 29,450

Accounting Policies [Line Items]

Inventories

2,864

2,771

$ 2,864

2,771

FCC licenses - typical term (in years)

10 years

Estimated period of ultimate revenues, from initial release or from delivery of first episode (years)

10 years

Cash and Cash Equivalents [Line Items]

Cash

2,654

$ 2,654

Cash and cash equivalents

$ 12,130

$ 5,204

$ 12,130

$ 5,204

$ 50,498

$ 5,788

Change in Accounting Estimate [Line Items]

Estimated economic useful life

21 years 6 months

21 years 6 months

Minimum [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Capitalized Contract Cost, Amortization Period

3 years

3 years

Maximum [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Capitalized Contract Cost, Amortization Period

5 years

5 years

ASU 2016-02 [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

ASU Adoption Date [CCYY-MM-DD format]

Jan. 1, 2019

ASU Early Adoption [true/false]

false

Transition Option Elected [Prospective/Retrospective/Modified Prospective/Modified Retrospective]

Modified Retrospective

Prior Period Not Restated [true/false]

true

Significant effect on the financial statements [Yes/No]

No

Lease, Practical Expedient, Land Easement [true false]

true

Operating lease liability

$ 22,121

Operating Lease, Right-of-Use Asset

22,121

Net Assets

20,960

Retained earnings

$ 316

ASU 2019-02 [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

ASU Adoption Date [CCYY-MM-DD format]

Jan. 1, 2019

ASU Early Adoption [true/false]

true

Transition Option Elected [Prospective/Retrospective/Modified Prospective/Modified Retrospective]

Prospective

Prior Period Not Restated [true/false]

true

Significant effect on the financial statements [Yes/No]

No

ASU 2019-02 [Member] | Programming Inventory Costs [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Other current assets

$ (2,274)

Other Assets

$ 2,274

ASU 2014-09 [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

ASU Adoption Date [CCYY-MM-DD format]

Jan. 1, 2018

ASU Early Adoption [true/false]

false

Transition Option Elected [Prospective/Retrospective/Modified Prospective/Modified Retrospective]

Modified Retrospective

Prior Period Not Restated [true/false]

true

Retained earnings

$ 2,342

Other Assets

(239)

Contract asset

1,737

Deferred contract acquisition costs

1,454

Other Liabilities

(212)

Deferred income tax liabilities

787

Noncontrolling interest

$ 35

ASU 2016-01 [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

ASU Adoption Date [CCYY-MM-DD format]

Jan. 1, 2018

Transition Option Elected [Prospective/Retrospective/Modified Prospective/Modified Retrospective]

Prospective

Retained earnings

$ 658

ASU 2016-01 [Member] | Accumulated Other Comprehensive Income [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Cumulative effect of accounting changes

$ (658)

ASU 2018-02 [Member]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Income tax effects reclassed to retained earnings

$ 1,529

Mexico [Member] | Spectrum Licenses [Member]

Change in Accounting Estimate [Line Items]

Estimated economic useful life

25 years

Software [Member] | Minimum [Member]

Accounting Policies [Line Items]

Property, Plant and Equipment, Useful Life

3 years

Software [Member] | Maximum [Member]

Accounting Policies [Line Items]

Property, Plant and Equipment, Useful Life

7 years

Money Market Funds [Member]

Cash and Cash Equivalents [Line Items]

Cash equivalents

$ 9,476

$ 9,476

Foreign Jurisdictions [Member]

Cash and Cash Equivalents [Line Items]

Cash and cash equivalents

$ 2,681

$ 2,681

Time Warner Inc. [Member]

Acquisition and Dispositions [Line Items]

Acquisition of business - acquisition period

Jun. 14, 2018

Jun. 14, 2018

[1]

With the adoption of ASU 2016-01, the unrealized (gains) losses on our equity investments are reclassified to retained earnings (see Note 1).

[2]

With the adoption of ASU 2018-02, the stranded tax effects resulting from the application of the Tax Cuts and Jobs Act are reclassified to retained earnings (see Note 1).

[3]

With the adoption of ASU 2016-01, the unrealized (gains) losses on our equity investments are reclassified to retained earnings (see Note 1).

[4]

Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).

[5]

Includes an asset abandonment charge (Note 7).

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share
Net Income	$ 2,704	[1],[2]	$ 3,949	[1]	$ 3,974	[1]	$ 4,348	[1]	$ 5,130	[1]	$ 4,816	[1]	$ 5,248	[1]	$ 4,759	[1]	$ 4,816	$ 5,248	$ 4,759	$ 14,975	$ 19,953	$ 29,847
Less:Net income attributable to noncontrolling interest																				(1,072)	(583)	(397)
Net Income attributable to AT&T	$ 2,394	[1],[2]	$ 3,700	[1]	$ 3,713	[1]	$ 4,096	[1]	$ 4,858	[1]	$ 4,718	[1]	$ 5,132	[1]	$ 4,662	[1]	$ 4,718	$ 5,132	$ 4,662	13,903	19,370	29,450
Less: Preferred stock dividends																				(3)	0	0
Net income attributable to common stock																				13,900	19,370	29,450
Share-based payment																				21	19	13
Numerator for diluted earnings per share																				$ 13,921	$ 19,389	$ 29,463
Weighted-average number of common shares outstanding																				7,319	6,778	6,164
Share-based payment (in shares)																				29	28	19
Denominator for diluted earnings per share																				7,348	6,806	6,183
Basic earnings per share attributable to Common Stock	$ 0.33	[3]	$ 0.50	[3]	$ 0.51	[3]	$ 0.56	[3]	$ 0.66	[3]	$ 0.65	[3]	$ 0.81	[3]	$ 0.75	[3]	$ 0.65	$ 0.81	$ 0.75	$ 1.90	$ 2.85	$ 4.77
Diluted earnings per share attributable to Common Stock	$ 0.33	[3]	$ 0.50	[3]	$ 0.51	[3]	$ 0.56	[3]	$ 0.66	[3]	$ 0.65	[3]	$ 0.81	[3]	$ 0.75	[3]	$ 0.65	$ 0.81	$ 0.75	$ 1.89	$ 2.85	$ 4.76
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).
[3]	Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year.

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - Subsequent Event [Member]	1 Months Ended
	Jan. 31, 2020
Subsequent Event [Line Items]
Subsequent Event, Date	Jan. 3, 2020
Earnings Per Share, Subsequent Events	We executed an accelerated share repurchase agreement with a third-party financial institution to repurchase AT&T common stock (see Note 17). Under the terms of the agreement, on January 3, 2020, we paid the financial institution $4,000 and received approximately 80% of the stock, or 82.3 million shares. The final number of shares to be repurchased under the agreement will be based on the average of the daily volume-weighted average prices of AT&T common stock during the repurchase period, which is expected to conclude late in the first quarter of 2020. Upon final settlement of the agreement, we may be entitled to receive additional shares of AT&T common stock, or, under certain circumstances, we may be required to deliver shares of AT&T common stock or make a cash payment, at our election.

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018	[1]	Jan. 01, 2017	[2]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income, beginning balance		$ 4,249	$ 7,017	$ 4,961
Other comprehensive income (loss) before reclassification, net of tax		2,635	(801)	1,661
Amounts reclassifed from accumulated OCI, net of tax		(1,414)	(1,309)	(1,134)
Net other comprehensive income (loss), net of tax		1,221	(2,110)	527
Amounts reclassified to retained earnings					$ (658)		$ 1,529
Accumulated other comprehensive income, ending balance		5,470	4,249	7,017
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income, beginning balance		(3,084)	(2,054)	(1,995)
Other comprehensive income (loss) before reclassification, net of tax		28	(1,030)	20
Amounts reclassifed from accumulated OCI, net of tax	[3]	0	0	0
Net other comprehensive income (loss), net of tax		28	(1,030)	20
Amounts reclassified to retained earnings					0		(79)
Accumulated other comprehensive income, ending balance		(3,056)	(3,084)	(2,054)
Net Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income, beginning balance		(2)	660	541
Other comprehensive income (loss) before reclassification, net of tax		50	(4)	187
Amounts reclassifed from accumulated OCI, net of tax	[3]	0	0	(185)
Net other comprehensive income (loss), net of tax		50	(4)	2
Amounts reclassified to retained earnings					(658)		117
Accumulated other comprehensive income, ending balance		48	(2)	660
Net Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income, beginning balance		818	1,402	744
Other comprehensive income (loss) before reclassification, net of tax		(900)	(597)	371
Amounts reclassifed from accumulated OCI, net of tax	[4]	45	13	39
Net other comprehensive income (loss), net of tax		(855)	(584)	410
Amounts reclassified to retained earnings					0		248
Accumulated other comprehensive income, ending balance		(37)	818	1,402
Defined Benefit Postretirement Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income, beginning balance		6,517	7,009	5,671
Other comprehensive income (loss) before reclassification, net of tax		3,457	830	1,083
Amounts reclassifed from accumulated OCI, net of tax	[5]	(1,459)	(1,322)	(988)
Net other comprehensive income (loss), net of tax		1,998	(492)	95
Amounts reclassified to retained earnings					$ 0		$ 1,243
Accumulated other comprehensive income, ending balance		$ 8,515	$ 6,517	$ 7,009
[1]	With the adoption of ASU 2016-01, the unrealized (gains) losses on our equity investments are reclassified to retained earnings (see Note 1).
[2]	With the adoption of ASU 2018-02, the stranded tax effects resulting from the application of the Tax Cuts and Jobs Act are reclassified to retained earnings (see Note 1).
[3]	(Gains) losses are included in Other income (expense) - net in the consolidated statements of income.
[4]	(Gains) losses are included in Interest expense in the consolidated statements of income (see Note 13).
[5]	The amortization of prior service credits associated with postretirement benefits is included in Other income (expense) in the consolidated statements of income (see Note 15).

Segment Information (Summary Of

Segment Information (Summary Of Operating Revenues And Expenses By Segment) (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments	4
Amortization of production costs	$ 9,587	$ 3,772	$ 0
WarnerMedia [Member] | Pre-Acquisition Released Programming Costs [Member]
Segment Reporting Information [Line Items]
Amortization of production costs	$ 472	$ 1,416

Segment Information (Reconcilia

Segment Information (Reconciliation of Revenue from Segments to Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019	[1],[2]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018	[1]	Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 46,821		$ 44,588		$ 44,957		$ 44,827		$ 47,993		$ 45,739		$ 38,986		$ 38,038		$ 45,739	$ 38,986	$ 38,038	$ 181,193	$ 170,756	$ 160,546
Operations and Support Expenses																				125,021	116,230	116,189
EBITDA																				56,172	54,526	44,357
Depreciation and Amortization																				28,217	28,430	24,387
Operating Income (Loss)	$ 5,321		$ 7,901		$ 7,500		$ 7,233		$ 6,160		$ 7,269		$ 6,466		$ 6,201		$ 7,269	$ 6,466	$ 6,201	27,955	26,096	19,970
Equity in net income (loss) of affiliates																				(6)	48	128
Segment Contribution																				18,468	24,873	15,139
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				184,843	172,054	159,529
Operations and Support Expenses																				122,706	113,843	107,569
EBITDA																				62,137	58,211	51,960
Depreciation and Amortization																				20,087	19,844	19,532
Operating Income (Loss)																				42,050	38,367	32,428
Equity in net income (loss) of affiliates																				189	59	58
Segment Contribution																				42,239	38,426	32,486
Eliminations and consolidations [Member]
Segment Reporting Information [Line Items]
Revenues																				(5,253)	(3,399)	(1,183)
Operations and Support Expenses																				(3,735)	(1,947)	31
EBITDA																				(1,518)	(1,452)	(1,214)
Depreciation and Amortization																				(2)	(1)	0
Operating Income (Loss)																				(1,516)	(1,451)	(1,214)
Certain Significant Items [Member]
Segment Reporting Information [Line Items]
Revenues																				0	0	(243)
Operations and Support Expenses																				2,082	899	3,880
EBITDA																				(2,082)	(899)	(4,123)
Depreciation and Amortization																				43	26	33
Operating Income (Loss)																				(2,125)	(925)	(4,156)
Communications [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				142,359	143,721	149,457
Operations and Support Expenses																				91,800	93,321	99,661
EBITDA																				50,559	50,400	49,796
Depreciation and Amortization																				18,329	18,292	18,308
Operating Income (Loss)																				32,230	32,108	31,488
Equity in net income (loss) of affiliates																				0	0	0
Segment Contribution																				32,230	32,108	31,488
Communications [Member] | Mobility [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				71,056	70,521	70,259
Operations and Support Expenses																				40,681	40,690	42,317
EBITDA																				30,375	29,831	27,942
Depreciation and Amortization																				8,054	8,263	7,931
Operating Income (Loss)																				22,321	21,568	20,011
Equity in net income (loss) of affiliates																				0	0	0
Segment Contribution																				22,321	21,568	20,011
Communications [Member] | Entertainment Group [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				45,126	46,460	49,995
Operations and Support Expenses																				35,028	36,430	38,903
EBITDA																				10,098	10,030	11,092
Depreciation and Amortization																				5,276	5,315	5,621
Operating Income (Loss)																				4,822	4,715	5,471
Equity in net income (loss) of affiliates																				0	0	0
Segment Contribution																				4,822	4,715	5,471
Communications [Member] | Business Wireline [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				26,177	26,740	29,203
Operations and Support Expenses																				16,091	16,201	18,441
EBITDA																				10,086	10,539	10,762
Depreciation and Amortization																				4,999	4,714	4,756
Operating Income (Loss)																				5,087	5,825	6,006
Equity in net income (loss) of affiliates																				0	0	0
Segment Contribution																				5,087	5,825	6,006
WarnerMedia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				33,499	18,941	430
Operations and Support Expenses																				23,797	12,966	335
EBITDA																				9,702	5,975	95
Depreciation and Amortization																				538	305	4
Operating Income (Loss)																				9,164	5,670	91
Equity in net income (loss) of affiliates																				162	25	(29)
Segment Contribution																				9,326	5,695	62
WarnerMedia [Member] | Turner [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				13,122	6,979	430
Operations and Support Expenses																				7,740	3,794	331
EBITDA																				5,382	3,185	99
Depreciation and Amortization																				235	131	4
Operating Income (Loss)																				5,147	3,054	95
Equity in net income (loss) of affiliates																				52	54	45
Segment Contribution																				5,199	3,108	140
WarnerMedia [Member] | Home Box Office [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				6,749	3,598	0
Operations and Support Expenses																				4,312	2,187	0
EBITDA																				2,437	1,411	0
Depreciation and Amortization																				102	56	0
Operating Income (Loss)																				2,335	1,355	0
Equity in net income (loss) of affiliates																				30	29	0
Segment Contribution																				2,365	1,384	0
WarnerMedia [Member] | Warner Bros. [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				14,358	8,703	0
Operations and Support Expenses																				11,816	7,130	0
EBITDA																				2,542	1,573	0
Depreciation and Amortization																				162	96	0
Operating Income (Loss)																				2,380	1,477	0
Equity in net income (loss) of affiliates																				(30)	(28)	0
Segment Contribution																				2,350	1,449	0
WarnerMedia [Member] | Other Media Revenues [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				(730)	(339)	0
Operations and Support Expenses																				(71)	(145)	4
EBITDA																				(659)	(194)	(4)
Depreciation and Amortization																				39	22	0
Operating Income (Loss)																				(698)	(216)	(4)
Equity in net income (loss) of affiliates																				110	(30)	(74)
Segment Contribution																				(588)	(246)	(78)
Latin America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				6,963	7,652	8,269
Operations and Support Expenses																				6,463	7,158	7,404
EBITDA																				500	494	865
Depreciation and Amortization																				1,162	1,238	1,218
Operating Income (Loss)																				(662)	(744)	(353)
Equity in net income (loss) of affiliates																				27	34	87
Segment Contribution																				(635)	(710)	(266)
Latin America [Member] | Vrio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				4,094	4,784	5,456
Operations and Support Expenses																				3,378	3,743	4,172
EBITDA																				716	1,041	1,284
Depreciation and Amortization																				660	728	849
Operating Income (Loss)																				56	313	435
Equity in net income (loss) of affiliates																				27	34	87
Segment Contribution																				83	347	522
Latin America [Member] | Mexico [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				2,869	2,868	2,813
Operations and Support Expenses																				3,085	3,415	3,232
EBITDA																				(216)	(547)	(419)
Depreciation and Amortization																				502	510	369
Operating Income (Loss)																				(718)	(1,057)	(788)
Equity in net income (loss) of affiliates																				0	0	0
Segment Contribution																				(718)	(1,057)	(788)
Xandr [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues																				2,022	1,740	1,373
Operations and Support Expenses																				646	398	169
EBITDA																				1,376	1,342	1,204
Depreciation and Amortization																				58	9	2
Operating Income (Loss)																				1,318	1,333	1,202
Equity in net income (loss) of affiliates																				0	0	0
Segment Contribution																				1,318	1,333	1,202
Corporate [Member]
Segment Reporting Information [Line Items]
Revenues																				1,603	2,101
Corporate [Member] | Consolidation [Member] | Acquisition-related Costs [Member]
Segment Reporting Information [Line Items]
Revenues																				(72)	(49)	0
Operations and Support Expenses																				960	1,185	798
EBITDA																				(1,032)	(1,234)	(798)
Depreciation and Amortization																				7,460	6,931	4,608
Operating Income (Loss)																				(8,492)	(8,165)	(5,406)
Corporate [Member] | Certain Significant Items [Member]
Segment Reporting Information [Line Items]
Revenues																				1,675	2,150	2,443
Operations and Support Expenses																				3,008	2,250	3,911
EBITDA																				(1,333)	(100)	(1,468)
Depreciation and Amortization																				629	1,630	214
Operating Income (Loss)																				$ (1,962)	$ (1,730)	$ (1,682)
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).

Segment Information (Reconcil_2

Segment Information (Reconciliation of Operating Profit (Loss) from Segments to Consolidated) (Details) - USD ($) $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019	[1],[2]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018	[1]	Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income	$ 5,321		$ 7,901		$ 7,500		$ 7,233		$ 6,160		$ 7,269		$ 6,466		$ 6,201		$ 7,269	$ 6,466	$ 6,201	$ 27,955	$ 26,096	$ 19,970
Interest expense																				8,422	7,957	6,300
Equity in net income (loss) of affiliates																				6	(48)	(128)
Other income (expense) - net																				(1,071)	6,782	1,597
Income Before Income Taxes																				18,468	24,873	15,139
Operating Segments [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				42,050	38,367	32,428
Equity in net income (loss) of affiliates																				(189)	(59)	(58)
Income Before Income Taxes																				42,239	38,426	32,486
Operating Segments [Member] | Communications [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				32,230	32,108	31,488
Equity in net income (loss) of affiliates																				0	0	0
Income Before Income Taxes																				32,230	32,108	31,488
Operating Segments [Member] | WarnerMedia [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				9,164	5,670	91
Equity in net income (loss) of affiliates																				(162)	(25)	29
Income Before Income Taxes																				9,326	5,695	62
Operating Segments [Member] | Latin America [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(662)	(744)	(353)
Equity in net income (loss) of affiliates																				(27)	(34)	(87)
Income Before Income Taxes																				(635)	(710)	(266)
Operating Segments [Member] | Xandr [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				1,318	1,333	1,202
Equity in net income (loss) of affiliates																				0	0	0
Income Before Income Taxes																				1,318	1,333	1,202
Certain Significant Items [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(2,125)	(925)	(4,156)
Certain Significant Items [Member] | Corporate and Other [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(1,962)	(1,730)	(1,682)
Merger and intergration charges
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(1,032)	(1,234)	(798)
Amortization of intangibles acquired
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(7,460)	(6,931)	(4,608)
Abandonments and impairments
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(1,458)	(46)	(2,914)
Employee separation charges
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(624)	(587)	(445)
Other noncash charges (credits) [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(43)	(111)	49
Natural disaster items
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				0	(181)	(626)
Tax Reform Special Bonus [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				0	0	(220)
Segment equity in net income of affiliates
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				(189)	(59)	(58)
Eliminations and consolidations [Member]
Segment Reporting Reconciling Item For Operating Income (Loss) From Segment To Consolidated Statements Of Income [Line Items]
AT&T Operating Income																				$ (1,516)	$ (1,451)	$ (1,214)
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).

Segment Information (Schedule o

Segment Information (Schedule of Revenues by Geographic Region) (Details) - USD ($) $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 46,821	[1],[2]	$ 44,588		$ 44,957		$ 44,827		$ 47,993	[1]	$ 45,739		$ 38,986		$ 38,038		$ 45,739	$ 38,986	$ 38,038	$ 181,193	$ 170,756	$ 160,546
Property, plant and equipment - net	130,128								131,473											130,128	131,473	125,222
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				162,344	154,795	149,841
Property, plant and equipment - net	122,567								123,457											122,567	123,457	118,200
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				6,137	4,073	1,064
Property, plant and equipment - net	1,854								1,634											1,854	1,634	392
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				3,198	3,100	2,913
Property, plant and equipment - net	3,648								3,467											3,648	3,467	3,619
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				2,761	2,724	2,948
Property, plant and equipment - net	1,057								1,213											1,057	1,213	1,447
All other Latin America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				3,219	3,055	2,743
Property, plant and equipment - net	544								1,217											544	1,217	1,294
Asia/Pacific Rim [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				2,651	2,214	829
Property, plant and equipment - net	390								408											390	408	194
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues																				883	795	208
Property, plant and equipment - net	$ 68								$ 77											$ 68	$ 77	$ 76
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).

Segment Information (Intersegme

Segment Information (Intersegment Details) (Details) - USD ($) $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019	[1],[2]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018	[1]	Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues [Abstract]
Total revenues	$ (46,821)		$ (44,588)		$ (44,957)		$ (44,827)		$ (47,993)		$ (45,739)		$ (38,986)		$ (38,038)		$ (45,739)	$ (38,986)	$ (38,038)	$ (181,193)	$ (170,756)	$ (160,546)
Operating Segments [Member]
Revenues [Abstract]
Total revenues																				(184,843)	(172,054)	(159,529)
Total Intersegment Revenues [Member]
Revenues [Abstract]
Total revenues																				3,344	1,888	134
Eliminations and consolidations [Member]
Revenues [Abstract]
Total revenues																				5,253	3,399	1,183
Communications [Member] | Operating Segments [Member]
Revenues [Abstract]
Total revenues																				(142,359)	(143,721)	(149,457)
Communications [Member] | Total Intersegment Revenues [Member]
Revenues [Abstract]
Total revenues																				26	13	0
WarnerMedia [Member] | Operating Segments [Member]
Revenues [Abstract]
Total revenues																				(33,499)	(18,941)	(430)
WarnerMedia [Member] | Total Intersegment Revenues [Member]
Revenues [Abstract]
Total revenues																				3,308	1,875	134
Latin America [Member] | Operating Segments [Member]
Revenues [Abstract]
Total revenues																				(6,963)	(7,652)	(8,269)
Latin America [Member] | Total Intersegment Revenues [Member]
Revenues [Abstract]
Total revenues																				0	0	0
Xandr [Member] | Operating Segments [Member]
Revenues [Abstract]
Total revenues																				(2,022)	(1,740)	(1,373)
Xandr [Member] | Total Intersegment Revenues [Member]
Revenues [Abstract]
Total revenues																				10	0	0
Consolidation [Member] | Eliminations and consolidations [Member]
Revenues [Abstract]
Total revenues																				$ 1,909	$ 1,511	$ 1,049
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).

Segment Information (Interseg_2

Segment Information (Intersegment Assets, Equity Affiliates Investments and Capital Expenditures Details) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total Assets	$ 551,669	$ 531,864
Investments in Equity Affiliates	3,695	6,245	$ 1,560
Capital Expenditures	19,635	21,251
Corporate and eliminations [Member]
Segment Reporting Information [Line Items]
Total Assets	(130,569)	(106,812)
Investments in Equity Affiliates	34	21
Capital Expenditures	263	310
Communications [Member]
Segment Reporting Information [Line Items]
Total Assets	521,252	485,357
Investments in Equity Affiliates	0	0
Capital Expenditures	17,410	19,509
WarnerMedia [Member]
Segment Reporting Information [Line Items]
Total Assets	137,264	132,453
Investments in Equity Affiliates	3,011	5,547
Capital Expenditures	1,013	581
Latin America [Member]
Segment Reporting Information [Line Items]
Total Assets	20,606	18,148
Investments in Equity Affiliates	650	677
Capital Expenditures	757	745
Xandr [Member]
Segment Reporting Information [Line Items]
Total Assets	3,116	2,718
Investments in Equity Affiliates	0	0
Capital Expenditures	$ 192	$ 106

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Contract with Customer, Asset and Liability [Abstract]
Beginning of period contract liability recorded as customer contract revenue during period	$ 5,394
Contract asset balance - current portion (in millions)	1,611	$ 1,244
Contract liability balance - current portion (in millions)	5,939	$ 5,752
Revenue, Performance Obligation [Abstract]
Aggregate amount of the transaction price allocated to remaining performance obligations (in millions)	$ 39,245
Aggregate amount of the transaction price allocated to remaining performance obligations (percentage)	60.00%
Minimum [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Amortization Period	3 years
Maximum [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Amortization Period	5 years
Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of customers exceeding threshold for significance	No	No	No
Threshold for customer significance (as a percent of consolidated revenues) (in hundredths)	10.00%	10.00%	10.00%
Deferred Customer Contract Acquisition Costs Member [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	$ 5,453	$ 3,974
Capitalized Contract Cost, Amortization (in millions)	2,174	1,433
Deferred Customer Contract Acquisition Costs Member [Member] | Other Current Assets [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	2,462	1,901
Deferred Customer Contract Fulfillment Cost Member [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	10,958	11,540
Capitalized Contract Cost, Amortization (in millions)	4,947	4,039
Deferred Customer Contract Fulfillment Cost Member [Member] | Other Current Assets [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	$ 4,519	$ 4,090

Revenue Recognition (Revenue Ca

Revenue Recognition (Revenue Categories) (Details) - USD ($) $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019	[1],[2]	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018	[1]	Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 46,821		$ 44,588		$ 44,957		$ 44,827		$ 47,993		$ 45,739		$ 38,986		$ 38,038		$ 45,739	$ 38,986	$ 38,038	$ 181,193	$ 170,756	$ 160,546
Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				57,452	56,401
Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				21,380	20,253
Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				11,908	13,751
Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				48,392	44,075
Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				10,631	6,541
Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				6,989	4,433
Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				6,747	6,891
Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				17,694	18,411
Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				1,603	2,101
Corporate and Other [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				549	638
Corporate and Other [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				51	52
Corporate and Other [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				155	36
Corporate and Other [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																					0
Corporate and Other [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																					0
Corporate and Other [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Corporate and Other [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				678	1,190
Corporate and Other [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				170	185
Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				184,843	172,054	159,529
Operating Segments [Member] | Communications [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				142,359	143,721	149,457
Operating Segments [Member] | Communications [Member] | Mobility [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				71,056	70,521	70,259
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				55,040	54,062
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				291	232
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Mobility [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				15,725	16,227
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				45,126	46,460	49,995
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				8,403	7,956
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				2,573	3,041
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				30,438	31,762
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				1,672	1,595
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				2,032	2,097
Operating Segments [Member] | Communications [Member] | Entertainment Group [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				8	9
Operating Segments [Member] | Communications [Member] | Business Wireline [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				26,177	26,740	29,203
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				12,926	12,245
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				9,180	10,674
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				3,286	2,998
Operating Segments [Member] | Communications [Member] | Business Wireline [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				785	823
Operating Segments [Member] | WarnerMedia [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				33,499	18,941	430
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				13,122	6,979	430
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				7,736	4,207
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				481	295
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				4,566	2,330
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				339	147
Operating Segments [Member] | WarnerMedia [Member] | Turner [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				6,749	3,598	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				5,814	3,201
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				925	391
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				10	6
Operating Segments [Member] | WarnerMedia [Member] | Home Box Office [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				14,358	8,703	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				88	47
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				13,532	8,216
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				41	53
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				697	387
Operating Segments [Member] | WarnerMedia [Member] | Warner Bros. [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				(730)	(339)
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				222	74
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				(1,058)	(518)
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				69	78
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				37	27
Operating Segments [Member] | WarnerMedia [Member] | Eliminations and other [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				6,963	7,652	8,269
Operating Segments [Member] | Latin America [Member] | Vrio [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				4,094	4,784	5,456
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				4,094	4,784
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Vrio [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				2,869	2,868	2,813
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				1,863	1,701
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Latin America [Member] | Mexico [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				1,006	1,167
Operating Segments [Member] | Xandr [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				2,022	1,740	1,373
Operating Segments [Member] | Xandr [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Xandr [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Xandr [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Xandr [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Xandr [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Xandr [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				2,022	1,740
Operating Segments [Member] | Xandr [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Operating Segments [Member] | Xandr [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Eliminations and consolidations [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues																				(5,253)	(3,399)	$ (1,183)
Eliminations and consolidations [Member] | Wireless service
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Eliminations and consolidations [Member] | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Eliminations and consolidations [Member] | Legacy Voice and Data
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Eliminations and consolidations [Member] | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues																				0	0
Eliminations and consolidations [Member] | Content
Disaggregation of Revenue [Line Items]
Total operating revenues																				(3,249)	(1,843)
Eliminations and consolidations [Member] | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues																				(1,672)	(1,595)
Eliminations and consolidations [Member] | Other
Disaggregation of Revenue [Line Items]
Total operating revenues																				(332)	39
Eliminations and consolidations [Member] | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues																				$ 0	$ 0
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).

Revenue Recognition (Deferred C

Revenue Recognition (Deferred Contract Acquisition and Fulfillment Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred Customer Contract Acquisition Costs Member [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	$ 5,453	$ 3,974
Capitalized Contract Cost, Amortization (in millions)	2,174	1,433
Deferred Customer Contract Acquisition Costs Member [Member] | Other Current Assets [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	2,462	1,901
Deferred Customer Contract Acquisition Costs Member [Member] | Other Assets [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	2,991	2,073
Deferred Customer Contract Fulfillment Cost Member [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	10,958	11,540
Capitalized Contract Cost, Amortization (in millions)	4,947	4,039
Deferred Customer Contract Fulfillment Cost Member [Member] | Other Current Assets [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	4,519	4,090
Deferred Customer Contract Fulfillment Cost Member [Member] | Other Assets [Member]
Capitalized Contract Cost, Net [Abstract]
Capitalized Contract Cost, Net (in millions)	$ 6,439	$ 7,450

Revenue Recognition (Contract A

Revenue Recognition (Contract Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Contract with Customer, Asset and Liability [Abstract]
Contract asset	$ 2,472	$ 1,896
Contract liability	$ 6,999	$ 6,856

Acquisitions, Dispositions An_3

Acquisitions, Dispositions And Other Adjustments (Time Warner, Otter and AppNexus Acquisitions Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended																			7 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2019		Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 14, 2018
Business Acquisition [Line Items]
Advances, Investments In, Collections, and Payments From Affiliates																						$ 365	$ 1,050	$ 0
Goodwill		$ 146,241								$ 146,370											$ 146,370	146,241	146,370	105,449
Acquisition of business - purchase price (in millions)																						1,809	43,309	(1,123)
Revenues		46,821	[1],[2]	$ 44,588		$ 44,957		$ 44,827		47,993	[1]	$ 45,739		$ 38,986		$ 38,038		$ 45,739	$ 38,986	$ 38,038		181,193	170,756	160,546
Operating Income (Loss)		5,321	[1],[2]	$ 7,901		$ 7,500		$ 7,233		6,160	[1]	$ 7,269		$ 6,466		$ 6,201		$ 7,269	$ 6,466	$ 6,201		27,955	26,096	19,970
Amortization expense																						7,932	8,347	4,626
WarnerMedia [Member]
Business Acquisition [Line Items]
Goodwill		40,879								40,698											40,698	40,879	40,698	0
Xandr [Member]
Business Acquisition [Line Items]
Goodwill		$ 1,466								1,403											1,403	$ 1,466	$ 1,403	$ 0
Time Warner Inc. [Member]
Business Acquisition [Line Items]
Acquisition of business - acquisition period	Jun. 14, 2018																						Jun. 14, 2018
Goodwill																									$ 38,801
Acquisition of business - purchase price (in millions)	$ 79,358
Time Warner Inc. [Member] | Cash [Member]
Business Acquisition [Line Items]
Acquisition of business - purchase price (in millions)	42,100
Time Warner Inc. [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Acquisition of business - purchase price (in millions)	$ 36,599
Time Warner Inc. [Member] | Acquisition [Member]
Business Acquisition [Line Items]
Revenues																					18,209
Operating Income (Loss)																					1,400
Amortization expense																					3,296
Otter Media [Member] | WarnerMedia [Member]
Business Acquisition [Line Items]
Acquisition of business - acquisition period																							Aug. 7, 2018
Advances, Investments In, Collections, and Payments From Affiliates																							$ 1,480
Acquisition of business - Equity Interest in Acquiree Remeasurement Gain																							395
Goodwill										1,239											1,239		1,239
Acquisition of business - purchase price (in millions)																							$ 157
AppNexus [Member] | Xandr [Member]
Business Acquisition [Line Items]
Acquisition of business - acquisition period																							Aug. 15, 2018
Goodwill										$ 1,220											$ 1,220		$ 1,220
Acquisition of business - purchase price (in millions)																							$ 1,432
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).

Acquisitions, Dispositions An_4

Acquisitions, Dispositions And Other Adjustments (Other Acquisitions Narrative) (Details) - Spectrum Licenses [Member] $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Indefinite-lived Intangible Assets [Line Items]
Assets Acquisition - acquisition period	Dec. 1, 2019
Auction 1000 [Member]
Indefinite-lived Intangible Assets [Line Items]
Payments to Acquire Intangible Assets	$ 982		$ 2,348
Net Cash Provided by (Used in) Investing Activities, Continuing Operations		$ 1,438
Acquisition of intangible assets through a group purchase - value/amount of assets acquired		$ 910
Assets Acquisition - acquisition period		Apr. 1, 2017
Assets Acquisition - number of markets (as shown)		18

Acquisitions, Dispositions An_5

Acquisitions, Dispositions And Other Adjustments (Dispositions Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Jun. 30, 2019	Apr. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Cash proceeds from sale of businesses and interest in affiliates			$ 4,684	$ 2,148	$ 59
Property, Plant and Equipment - Net			130,128	$ 131,473	$ 125,222
Hudson Yards North Tower Holdings LLC [Member] | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Business Acquisition [Line Items]
Disposal Date	Jun. 30, 2019
Cash proceeds from sale of businesses and interest in affiliates			2,081
Gain (Loss) on sale of investment			(100)
Brookfield Infrastructure Partners [Member] | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Business Acquisition [Line Items]
Disposal Date				Dec. 31, 2018
Proceeds from assets sold				$ 1,100
Gain (Loss) on sale of investment				432
Property, Plant and Equipment - Net				298
Goodwill				$ 215
Auction 1000 [Member] | Spectrum Licenses [Member]
Business Acquisition [Line Items]
Disposal Date				Dec. 31, 2018
Hulu [Member] | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Business Acquisition [Line Items]
Disposal Date		Apr. 30, 2019
Cash proceeds from sale of businesses and interest in affiliates			1,430
Gain (Loss) on sale of investment			$ 740

Acquisitions, Dispositions An_6

Acquisitions, Dispositions And Other Adjustments (Held-For-Sale) (Narrative) (Details) - Puerto Rico and U.S. Virgin Islands Wireline and Wireless Operations [Member] - Disposal Group, Held-for-sale, Not Discontinued Operations [Member] - Spectrum Licenses [Member] - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2019	Dec. 31, 2019
Assets Held-For-Sale [Line Items]
Date of agreement	Oct. 31, 2019
Assets held-for-sale transaction price		$ 1,950
Timing of Disposal		We expect the transaction to close in the first half of 2020, subject to customary closing conditions.
Other Current Assets [Member]
Assets Held-For-Sale [Line Items]
Property, plant and equipment - net		$ 700
Indefinite-lived Intangible Assets		1,100
Goodwill		300
Accounts Payable and Accrued Liabilities [Member]
Assets Held-For-Sale [Line Items]
Net tax liabilities		$ 400

Acquisitions, Dispositions An_7

Acquisitions, Dispositions And Other Adjustments (Fair Value of Assets Acquired And Liabilities Assumed) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Jun. 14, 2018	Dec. 31, 2017
Assets acquired
Noncurrent inventories and theatrical film and television production costs	$ 12,434	$ 7,713
Goodwill	146,241	146,370		$ 105,449
Liabilities assumed
Debt maturing within one year	$ 11,838	$ 10,255
Time Warner Inc. [Member]
Assets acquired
Cash			$ 1,889
Accounts Receivable			9,020
All other current assets			2,913
Noncurrent inventories and theatrical film and television production costs			5,591
Property, plant and equipment			4,693
Investments and other assets			9,438
Goodwill			38,801
Total assets acquired			129,572
Liabilities assumed
Current liabilities, excluding current portion of long-term debt			8,294
Debt maturing within one year			4,471
Long-term debt			18,394
Other noncurrent liabilities			19,054
Total liabilities assumed			50,213
Net assets acquired			79,359
Noncontrolling interest			(1)
Aggregate value of consideration paid			79,358
Time Warner Inc. [Member] | Distribution Networks [Member]
Assets acquired
Intangible assets subject to amortization			18,040
Time Warner Inc. [Member] | Released television and film content [Member]
Assets acquired
Intangible assets subject to amortization			10,806
Time Warner Inc. [Member] | Trademarks and trade names [Member]
Assets acquired
Intangible assets subject to amortization			18,081
Time Warner Inc. [Member] | Other [Member]
Assets acquired
Intangible assets subject to amortization			$ 10,300

Acquisitions, Dispositions An_8

Acquisitions, Dispositions And Other Adjustments (Pro-Forma Consolidated Results Of Operations) (Details) - Time Warner Inc. [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition Pro Forma Information [Line Items]
Total operating revenues	$ 183,651	$ 188,769
Net Income Attributable to AT&T	$ 20,814	$ 31,380
Basic Earnings Per Share Attributable to AT&T	$ 2.86	$ 4.30
Diluted Earnings Per Share Attributable to AT&T	$ 2.85	$ 4.26

Property, Plant And Equipment_2

Property, Plant And Equipment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 333,538	$ 330,690
Accumulated depreciation and amortization		203,410	199,217
Property, plant and equipment - net		130,128	131,473	$ 125,222
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 2,651	$ 2,714
Land [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		0 years	0 years
Land [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		0 years	0 years
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 38,924	$ 38,013
Buildings and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		2 years	2 years
Buildings and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		44 years	44 years
Central Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	[1]	$ 96,061	$ 95,173
Central Office Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		3 years	3 years
Central Office Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		10 years	10 years
Cable, Wiring And Conduit [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 72,042	$ 73,397
Cable, Wiring And Conduit [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		15 years	15 years
Cable, Wiring And Conduit [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		50 years	50 years
Satellites [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 2,489	$ 2,961
Satellites [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		14 years	14 years
Satellites [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		17 years	17 years
Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 94,951	$ 93,782
Other Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		3 years	3 years
Other Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		20 years	20 years
Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 22,244	$ 19,124
Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		3 years	3 years
Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		7 years	7 years
Under Construction [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost		$ 4,176	$ 5,526
Under Construction [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		0 years	0 years
Under Construction [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		0 years	0 years
[1]	Includes certain network software.

Property, Plant And Equipment_3

Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 20,285	$ 20,083	$ 19,761
Assets Disposed of by Method Other than Sale, in Period of Disposition, Gain (Loss) on Disposition		(1,458)	(46)	(2,914)
Copper Network Assets [Member]
Property, Plant and Equipment [Line Items]
Assets Disposed of by Method Other than Sale, in Period of Disposition, Gain (Loss) on Disposition	$ 1,290			2,883
Software [Member]
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 3,313	$ 3,092	$ 2,810

Leases (Narrative) (Details)

Leases (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019
Leases [Line Items]
Operating lease, option to terminate leases	some of our leases include options to terminate the leases within one year
Finance Lease, option to terminate leases	some of our leases include options to terminate the leases within one year
Maximum [Member]
Leases [Line Items]
Operating Lease, remaining term of contract	15 years
Finance Lease, remaining term of contract	15 years

Leases (Components of Lease Exp

Leases (Components of Lease Expense) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Operating Lease [Abstract]
Operating Lease Cost	$ 5,684
Finance Lease [Abstract]
Amortization of right-of-use assets	271
Interest on lease obligation	169
Finance Lease [Member]
Finance Lease [Abstract]
Total finance lease cost	$ 440

Leases (Supplemental Balance Sh

Leases (Supplemental Balance Sheet Information Related to Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Lease [Abstract]
Operating lease right-of-use assets	$ 24,039	$ 0
Accounts payable and accrued liabilities	3,451
Operating lease liabilities	21,804	0
Total operating lease obligation	25,255
Finance Lease [Abstract]
Property, plant and equipment, at cost	3,534
Accumulated depreciation and amortization	(1,296)
Property, plant and equipment - net	2,238
Current portion of long-term debt	162
Long-term debt	1,872
Total finance lease obligation	$ 2,034	$ 1,911
Operating Lease, Weighted Average Remaining Lease Term	8 years 4 months 24 days
Finance Lease, Weighted Average Remaining Lease Term	10 years 3 months 18 days
Operating Lease, Weighted Average Discount Rate	4.20%
Finance Lease, Weighted Average Discount Rate	8.40%

Leases (Future Minimum Maturiti

Leases (Future Minimum Maturities of Lease Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Leases [Abstract]
2020	$ 4,723
2021	4,349
2022	4,028
2023	3,611
2024	3,078
Thereafter	11,366
Total lease payments	31,155
Less: imputed interest	(5,900)
Total	25,255
Finance Leases [Abstract]
2020	340
2021	305
2022	289
2023	274
2024	258
Thereafter	1,649
Total lease payments	3,115
Less: inputed interest	(1,081)
Total	$ 2,034	$ 1,911

Goodwill And Other Intangible_3

Goodwill And Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill And Other Intangible Assets
Amortization expense for definite-life intangible assets for the year	$ 7,932	$ 8,347	$ 4,626
Estimated amortization expense in 2020	6,614
Estimated amortization expense in 2021	5,683
Estimated amortization expense in 2022	4,961
Estimated amortization expense in 2023	4,299
Estimated amortization expense in 2024	$ 3,644
Finite Lived Intangible Assets [Line Items]
Estimated economic useful life	21 years 6 months	21 years 6 months
Intangible Assets	$ 82,150	$ 79,365
Trademarks and trade names [Member]
Finite Lived Intangible Assets [Line Items]
Estimated economic useful life	37 years 3 months 18 days	37 years 3 months 18 days
Write-offs of fully amortized finite-lived intangible assets		$ 2,892
Intangible Assets	$ 18,359	$ 18,371
Trademarks and trade names [Member] | SKY Brasil [Member]
Finite Lived Intangible Assets [Line Items]
Goodwill impairment	$ 145
Customer Lists And Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Estimated economic useful life	9 years 1 month 6 days	9 years 1 month 6 days
Write-offs of fully amortized finite-lived intangible assets		$ 2,890
Intangible Assets	$ 20,304	$ 20,516
License [Member] | Mexico [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Method	straight-line basis
Finite-Lived Intangible Assets, Remaining Amortization Period	20 years
Estimated economic useful life	25 years
Intangible Assets	$ 1,561

Goodwill And Other Intangible_4

Goodwill And Other Intangible Assets (Summary Of Changes In Carrying Amount Of Goodwill, By Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Beginning balance	$ 146,370	$ 105,449
Reallocation		0
Acquisition	66	41,678
Dispositions, currency exchange and other	(195)	(757)
Ending balance	146,241	146,370
Business Solutions [Member]
Goodwill [Roll Forward]
Beginning balance	0	45,395
Reallocation		(45,395)
Acquisition	0	0
Dispositions, currency exchange and other	0	0
Ending balance	0	0
Consumer Mobility [Member]
Goodwill [Roll Forward]
Beginning balance	0	16,540
Reallocation		(16,540)
Acquisition	0	0
Dispositions, currency exchange and other	0	0
Ending balance	0	0
Communications [Member]
Goodwill [Roll Forward]
Beginning balance	100,551	39,280
Reallocation		61,075
Acquisition	0	422
Dispositions, currency exchange and other	(317)	(226)
Ending balance	100,234	100,551
WarnerMedia [Member]
Goodwill [Roll Forward]
Beginning balance	40,698	0
Reallocation		681
Acquisition	0	40,036
Dispositions, currency exchange and other	181	(19)
Ending balance	40,879	40,698
Latin America Business Segment [Member]
Goodwill [Roll Forward]
Beginning balance	3,718	4,234
Reallocation		(32)
Acquisition	0	0
Dispositions, currency exchange and other	(56)	(484)
Ending balance	3,662	3,718
Xandr [Member]
Goodwill [Roll Forward]
Beginning balance	1,403	0
Reallocation		211
Acquisition	66	1,220
Dispositions, currency exchange and other	(3)	(28)
Ending balance	$ 1,466	$ 1,403

Goodwill And Other Intangible_5

Goodwill And Other Intangible Assets (Schedule Of Amortized Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 82,150	$ 79,365
Accumulated amortization	25,392	17,610
Foreign Currency Translation Adjustments	$ (533)	$ (346)
Finite-Lived Intangible Assets, Weighted-Average Useful Life	21 years 6 months	21 years 6 months
Wireless Acquisitions [Member]
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 2,981	$ 0
Accumulated amortization	156	0
Foreign Currency Translation Adjustments	$ (243)	$ 0
Finite-Lived Intangible Assets, Weighted-Average Useful Life	24 years 6 months	24 years 6 months
Trademarks and trade names [Member]
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 18,359	$ 18,371
Accumulated amortization	853	293
Foreign Currency Translation Adjustments	$ (6)	$ (7)
Finite-Lived Intangible Assets, Weighted-Average Useful Life	37 years 3 months 18 days	37 years 3 months 18 days
Distribution Networks [Member]
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 18,138	$ 18,040
Accumulated amortization	2,793	971
Foreign Currency Translation Adjustments	$ 0	$ 0
Finite-Lived Intangible Assets, Weighted-Average Useful Life	10 years	10 years
Released Television And Film Content [Member]
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 10,941	$ 10,814
Accumulated amortization	4,974	2,988
Foreign Currency Translation Adjustments	$ 0	$ 0
Finite-Lived Intangible Assets, Weighted-Average Useful Life	16 years 4 months 24 days	16 years 4 months 24 days
Customer Lists And Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 20,304	$ 20,516
Accumulated amortization	14,773	12,451
Foreign Currency Translation Adjustments	$ (281)	$ (314)
Finite-Lived Intangible Assets, Weighted-Average Useful Life	9 years 1 month 6 days	9 years 1 month 6 days
Other [Member]
Finite Lived Intangible Assets [Line Items]
Intangible Assets	$ 11,427	$ 11,624
Accumulated amortization	1,843	907
Foreign Currency Translation Adjustments	$ (3)	$ (25)
Finite-Lived Intangible Assets, Weighted-Average Useful Life	20 years 4 months 24 days	20 years 4 months 24 days

Goodwill And Other Intangible_6

Goodwill And Other Intangible Assets (Schedule Of Indefinite-Life Intangible Assets Not Subject To Amortization) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Indefinite-lived Intangible Assets [Line Items]
Gross carrying amount	$ 101,392	$ 102,418
Licenses [Member]
Indefinite-lived Intangible Assets [Line Items]
Gross carrying amount	83,623	84,442
Orbital Slots [Member]
Indefinite-lived Intangible Assets [Line Items]
Gross carrying amount	11,702	11,702
Trademarks and trade names [Member]
Indefinite-lived Intangible Assets [Line Items]
Gross carrying amount	$ 6,067	$ 6,274

Equity Method Investments (Narr

Equity Method Investments (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended		12 Months Ended
	Oct. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Time Warner Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Effective Date of Acquisition		Jun. 14, 2018					Jun. 14, 2018
Time Warner Inc. [Member] | Equity Method Investment [Member]
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Effective Date of Acquisition							Dec. 31, 2018
Difference between fair value and proportional book value of investments' net assets						$ 2,135
Difference between fair value and proportional book value of investments' net assets, amortization treatment						$1,397 is attributed to amortizing intangibles, which will be amortized into earnings in our “Equity net income (loss) of affiliates” over a weighted-average life of 19.4 years.
Hudson Yards North Tower Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Sale of interst by parent						$ 1,681	$ 0
Hudson Yards North Tower Holdings LLC [Member] | Equity Method Investment [Member]
Schedule of Equity Method Investments [Line Items]
Disposition of business - period of sale of subsidiary			Jun. 30, 2019
HBO Latin America Group [Member] | Equity Method Investment [Member]
Schedule of Equity Method Investments [Line Items]
Company's ownership interest in investee						88.20%
Date of agreement	Oct. 31, 2019
Acquisition of interests held by noncontrolling owners	$ 230
HBO Latin America Group [Member] | Equity Method Investment [Member] | Forecast [Member]
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Effective Date of Acquisition				Dec. 31, 2020
Hulu [Member]
Schedule of Equity Method Investments [Line Items]
Sale of interst by parent						$ 689	$ 0
Hulu [Member] | Equity Method Investment [Member]
Schedule of Equity Method Investments [Line Items]
Disposition of business - period of sale of subsidiary			Jun. 30, 2019
Central European Media Enterprises Ltd. [Member] | Equity Method Investment [Member]
Schedule of Equity Method Investments [Line Items]
Company's ownership interest in investee						65.70%
Date of agreement	Oct. 31, 2019
Sale of interst by parent	$ 1,100
Central European Media Enterprises Ltd. [Member] | Equity Method Investment [Member] | Forecast [Member]
Schedule of Equity Method Investments [Line Items]
Disposition of business - period of sale of subsidiary					Jun. 30, 2020
SKY Mexico [Member] | Equity Method Investment [Member]
Schedule of Equity Method Investments [Line Items]
Company's ownership interest in investee						41.30%

Equity Method Investments (Reco

Equity Method Investments (Reconciliation Of Investments In Equity Affiliates) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Beginning of year	$ 6,245	$ 1,560
Additional investments	448	237
Time Warner investments acquired	0	4,912
Equity in net income (loss) of affiliates	(6)	48	$ 128
Dividends and Distributions received	(301)	(243)
Currency translation adjustments	(10)	(14)
Other adjustments	(35)	7
End of year	3,695	6,245	$ 1,560
Hudson Yards North Tower Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Disposition of investments	1,681	0
Hulu [Member]
Schedule of Equity Method Investments [Line Items]
Disposition of investments	689	0
Game Show Network [Member]
Schedule of Equity Method Investments [Line Items]
Disposition of investments	288	0
Otter Media [Member]
Schedule of Equity Method Investments [Line Items]
Acquisition of remaining interest in Otter Media	$ 0	$ (166)

Inventories and Theatrical Fi_3

Inventories and Theatrical Film and Television Production Costs (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Inventory Net [Abstract]
Programming costs, less amortization	[1]	$ 4,599		$ 4,097
Other inventory, primarily DVD and Blu-ray Discs		96		146
Total inventories		4,695		4,243
Less: current portion of inventory		(96)		(2,420)
Total noncurrent inventories		4,599		1,823
Theatrical film production costs:
Released, less amortization	[2]	392		451
Completed and not released	[2]	437		435
In production	[2]	1,475		866
Development and pre-production	[2]	171		159
Television production costs:
Released, less amortization	[2]	1,752		965
Completed and not released	[2]	1,344		1,087
In production	[2]	2,207		1,898
Development and pre-production	[2]	57		29
Total theatrical film and television production costs	[2]	7,835		5,890
Total noncurrent inventories and theatrical film and television production costs		12,434		7,713
Finite Lived Intangible Assets [Line Items]
Other Assets - current		18,364		17,704
Programming Inventory Costs [Member] | Accounting Standards Update 2019-02 [Member]
Finite Lived Intangible Assets [Line Items]
Other Assets - current			$ (2,274)
Other Assets			$ 2,274
Film and Television Libraries [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, net		$ 5,967		$ 7,826
Percentage of unamortized film costs		95.00%
Film costs, amortized in next operating cycle		$ 2,195
[1]	Includes the costs of certain programming rights, primarily sports, for which payments have been made prior to the related rights being received.
[2]	Does not include $5,967, and $7,826 of acquired film and television library intangible assets as of December 31, 2019, and 2018, respectively, which are included in “Other Intangible Assets – Net” on our consolidated balance sheet.

Debt (Summary Of Long-Term Debt

Debt (Summary Of Long-Term Debt Of AT&T And Its Subsidiaries) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unamortized (discount) premium - net		$ (2,996)	$ (2,526)
Unamortized issuance costs		(452)	(466)
Total notes and debentures		161,109	171,529
Finance lease obligations		2,034	1,911
Total long-term debt and capital lease obligations		163,143	173,440
Current maturities of long-term debt		(11,834)	(7,190)
Total long-term debt		151,309	166,250
Notes And Debentures [Member]
Debt Instrument [Line Items]
Total notes and debentures		$ 164,557	$ 174,521
Notes And Debentures Maturing 2019-2039 [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date range, start		Dec. 31, 2019	Dec. 31, 2019
Debt instrument, maturity date range, end		Dec. 31, 2039	Dec. 31, 2039
Total notes and debentures	[1]	$ 17,404	$ 14,404
Notes And Debentures Maturing 2019-2039 [Member] | Notes And Debentures [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		1.80%	1.80%
Notes And Debentures Maturing 2019-2039 [Member] | Notes And Debentures [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		2.99%	2.99%
Notes And Debentures Maturing 2019-2050 [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date range, start		Dec. 31, 2019	Dec. 31, 2019
Debt instrument, maturity date range, end		Dec. 31, 2050	Dec. 31, 2050
Total notes and debentures	[1]	$ 102,595	$ 104,291
Notes And Debentures Maturing 2019-2050 [Member] | Notes And Debentures [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		3.00%	3.00%
Notes And Debentures Maturing 2019-2050 [Member] | Notes And Debentures [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		4.99%	4.99%
Notes And Debentures Maturing 2019-2095 [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date range, start		Dec. 31, 2019	Dec. 31, 2019
Debt instrument, maturity date range, end		Dec. 31, 2095	Dec. 31, 2095
Total notes and debentures	[1]	$ 34,513	$ 37,175
Notes And Debentures Maturing 2019-2095 [Member] | Notes And Debentures [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		5.00%	5.00%
Notes And Debentures Maturing 2019-2095 [Member] | Notes And Debentures [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		6.99%	6.99%
Notes And Debentures Maturing 2019-2097 [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date range, start		Dec. 31, 2019	Dec. 31, 2019
Debt instrument, maturity date range, end		Dec. 31, 2097	Dec. 31, 2097
Total notes and debentures	[1]	$ 5,050	$ 5,976
Notes And Debentures Maturing 2019-2097 [Member] | Notes And Debentures [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		7.00%	7.00%
Notes And Debentures Maturing 2019-2097 [Member] | Notes And Debentures [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instument - stated percentage rate		9.15%	9.15%
Credit agreement borrowings [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Total notes and debentures		$ 4,969	$ 12,618
Other Debt [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Total notes and debentures		0	89
Fair value of interest rate swaps recorded in debt [Member] | Notes And Debentures [Member]
Debt Instrument [Line Items]
Total notes and debentures		$ 26	$ (32)
[1]	Maturities assume putable debt is redeemed by the holders at the next opportunity.

Debt (Debt Maturing Within One

Debt (Debt Maturing Within One Year) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure
Current maturities of long-term debt		$ 11,834	$ 7,190
Commercial paper		0	3,048
Bank borrowings	[1]	4	4
Other		0	13
Total		$ 11,838	$ 10,255
[1]	Outstanding balance of short-term credit facility of a foreign subsidiary.

Debt (Long-Term Debt - Schedule

Debt (Long-Term Debt - Scheduled Repayments) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Debt Disclosure
Long-term debt repayments scheduled for 2020	$ 12,149	[1]
Long-term debt repayments scheduled for 2021	11,036	[1]
Long-term debt repayments scheduled for 2022	11,189	[1]
Long-term debt repayments scheduled for 2023	10,037	[1]
Long-term debt repayments scheduled for 2024	11,225	[1]
Long-term debt repayments scheduled for the period thereafter	$ 112,429	[1]
Weighted average interest rate of long-term debt repayment scheduled for 2020	2.90%
Weighted average interest rate of long-term debt repayment scheduled for 2021	3.80%
Weighted average interest rate of long-term debt repayment scheduled for 2022	3.50%
Weighted average interest rate of long-term debt repayment scheduled for 2023	3.50%
Weighted average interest rate of long-term debt repayment scheduled for 2024	3.60%
Weighted average interest rate of long-term debt repayment scheduled for the period thereafter	4.80%
[1]	Debt repayments assume putable debt is redeemed by the holders at the next opportunity.

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt Instrument Weighted Average Interest Rate	4.40%	4.40%
Debt Instrument - principal/face amount	$ 17,235
Debt Issued in Foreign Markets [Member]
Debt Instrument [Line Items]
Debt Instrument - principal/face amount	$ 42,485	$ 41,356
Annual Put Reset Securities [Member]
Debt Instrument [Line Items]
Debt instruments - maturity date	Apr. 30, 2021
Debt Instrument - principal/face amount	$ 1,000
Zero Coupon [Member]
Debt Instrument [Line Items]
Debt instruments - maturity date	May 31, 2022
Debt Instrument - principal/face amount	$ 500
Debt instrument - redemption amount	$ 592

Debt (Financing Activities) (Na

Debt (Financing Activities) (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Feb. 29, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt			$ 17,039	$ 41,875	$ 48,793
Repayment of long-term debt			27,592	$ 52,643	$ 12,339
Debt Instrument - principal/face amount			$ 17,235
Debt Instrument Weighted Average Maturity Period			9 years
Debt Instrument Weighted Average Interest Rate			4.40%	4.40%
Debt Instrument - debt redeemed			$ 27,440
Debt Instrument, Repurchase Date			Dec. 19, 2019
Debt Instrument, Repurchased Face Amount			$ 1,409
Debt Instrument, Issuer			various subsidiaries
AT&T Inc. 4.600% Global Notes Due 2045 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Dec. 31, 2045
Debt instument - stated percentage rate	4.60%
Debt Instrument - debt redeemed	$ 2,619
Debt Instrument, Repurchase Date	Feb. 29, 2020
AT&T Inc. 4.000% Global Notes Due 2049 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Dec. 31, 2049
Proceeds from Issuance of Long-term Debt	$ 2,995
Debt instument - stated percentage rate	4.00%
Weighted Average [Member]
Debt Instrument [Line Items]
Debt Instrument Weighted Average Interest Rate			3.40%
Weighted Average [Member] | Various Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Weighted Average Interest Rate			3.50%
WarnerMedia [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt		$ 11,041
Repayment of long-term debt		$ 11,041
Debt Instrument, Repurchase Date		Jun. 30, 2019
Debt Instrument, Repurchased Face Amount		$ 590
Debt Instrument, Issuer		WarnerMedia subsidiaries
WarnerMedia [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument Weighted Average Interest Rate		1.95%
WarnerMedia [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Weighted Average Interest Rate		9.15%

Debt (Credit Facilities) (Narra

Debt (Credit Facilities) (Narrative) (Details) - USD ($)	1 Months Ended		12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Line Of Credit Facility [Line Items]
Repayment of long-term debt			$ 27,592,000,000	$ 52,643,000,000	$ 12,339,000,000
Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity		$ 15,000,000,000		15,000,000,000
Credit agreement - advances outstanding		0		$ 0
Line of Credit Facility, Covenant Terms				Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement’s relevant Applicable Margin by 2.00% per annum.
Amended and Restated Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Credit agreement - initiation date				Dec. 1, 2018
Credit agreement - maturity date				Dec. 11, 2021
Credit agreement - Term of Loan				5 years
Line of Credit Facility, Covenant Terms				Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement’s relevant Applicable Margin by 2.00% per annum.
Amended and Restated Credit Agreement [Member] | Additional Margin Upon Default [Member]
Line Of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate				2.00%
Five Year Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity		$ 7,500,000,000		$ 7,500,000,000
Credit agreement - initiation date		Dec. 31, 2018
Credit agreement - maturity date				Dec. 11, 2023
Credit agreement - Term of Loan				5 years
Line of Credit Facility, Covenant Terms				Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement’s relevant Applicable Margin by 2.00% per annum.
Five Year Credit Agreement [Member] | Additional Margin Upon Default [Member]
Line Of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate				2.00%
September 2019 Term Loan [Member] | Bank of America, N.A. [Member]
Line Of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity	$ 1,300,000,000
Credit agreement - initiation date	Sep. 30, 2019
Credit agreement - maximum amount outstanding during period			$ 1,300,000,000
Credit agreement - advances outstanding	$ 1,300,000,000
Line of Credit Facility, Covenant Terms			Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement's relevant Applicable Margin by 2.00% per annum.
Repayment of long-term debt			$ 0
September 2019 Term Loan [Member] | Bank of America, N.A. [Member] | Additional Margin Upon Default [Member]
Line Of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			2.00%
1.25 year BAML Tranche A Facility Term Loan [Member] | Bank of America, N.A. [Member]
Line Of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity	400,000,000
Credit agreement - initiation date			Sep. 1, 2019
Credit agreement - maturity date			Dec. 1, 2020
Credit agreement - Term of Loan			1 year 3 months
Credit agreement - maximum amount outstanding during period			$ 400,000,000
Credit agreement - advances outstanding	400,000,000
Line of Credit Facility, Covenant Terms			Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement's relevant Applicable Margin by 2.00% per annum.
Repayment of long-term debt			$ 0
1.25 year BAML Tranche A Facility Term Loan [Member] | Bank of America, N.A. [Member] | Additional Margin Upon Default [Member]
Line Of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			2.00%
2.25 year BAML Tranche B Facility Term Loan [Member] | Bank of America, N.A. [Member]
Line Of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity	400,000,000
Credit agreement - initiation date			Sep. 1, 2019
Credit agreement - maturity date			Dec. 1, 2021
Credit agreement - Term of Loan			2 years 3 months
Credit agreement - maximum amount outstanding during period			$ 400,000,000
Credit agreement - advances outstanding	400,000,000
Line of Credit Facility, Covenant Terms			Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement's relevant Applicable Margin by 2.00% per annum.
Repayment of long-term debt			$ 0
2.25 year BAML Tranche B Facility Term Loan [Member] | Bank of America, N.A. [Member] | Additional Margin Upon Default [Member]
Line Of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			2.00%
3.25 year BAML Tranche C Facility Term Loan [Member] | Bank of America, N.A. [Member]
Line Of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity	500,000,000
Credit agreement - initiation date			Sep. 1, 2019
Credit agreement - maturity date			Dec. 1, 2022
Credit agreement - Term of Loan			3 years 3 months
Credit agreement - maximum amount outstanding during period			$ 500,000,000
Credit agreement - advances outstanding	$ 500,000,000
Line of Credit Facility, Covenant Terms			Each of the Agreements contains covenants that are customary for an issuer with an investment grade senior debt credit rating, as well as a net debt-to-EBITDA (earnings before interest, taxes, depreciation and amortization, and other modifications described in each agreement) financial ratio covenant requiring AT&T to maintain, as of the last day of each fiscal quarter, a ratio of not more than 3.5-to-1. The events of default are customary for agreements of this type and such events would result in the acceleration of, or would permit the lenders to accelerate, as applicable, required payments and would increase each agreement's relevant Applicable Margin by 2.00% per annum.
Repayment of long-term debt			$ 0
3.25 year BAML Tranche C Facility Term Loan [Member] | Bank of America, N.A. [Member] | Additional Margin Upon Default [Member]
Line Of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			2.00%

Debt (Credit Agreement) (Narrat

Debt (Credit Agreement) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019
Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Credit agreement - term loan description	Each of the Credit Agreements provides that we and lenders representing more than 50% of the facility amount may agree to extend their commitments under such Credit Agreement for two one-year periods beyond the initial termination date. We have the right to terminate, in whole or in part, amounts committed by the lenders under each of the Credit Agreements in excess of any outstanding advances; however, any such terminated commitments may not be reinstated.
Credit agreement - base rate	Advances under these agreements would bear interest, at AT&T’s option, either: at a variable annual rate equal to: (1) the highest of (but not less than zero) (a) the rate of interest announced publicly by Citibank in New York, New York, from time to time, as Citibank’s base rate, (b) 0.5% per annum above the federal funds rate, and (c) the London interbank offered rate (or the successor thereto) (“LIBOR”) applicable to dollars for a period of one month plus 1.00%, plus (2) an applicable margin, as set forth in the applicable Credit Agreement (the “Applicable Margin for Base Advances”); or at a rate equal to: (i) LIBOR (adjusted upwards to reflect any bank reserve costs) for a period of one, two, three or six months, as applicable, plus (ii) an applicable margin, as set forth in the applicable Credit Agreement (the “Applicable Margin for Eurodollar Rate Advances”).
Amended and Restated Credit Agreement [Member] | High Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	7.00%
Amended and Restated Credit Agreement [Member] | Moderate Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	8.00%
Amended and Restated Credit Agreement [Member] | Low Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	10.00%
Amended and Restated Credit Agreement [Member] | Very Low Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	12.50%
Five Year Credit Agreement [Member]
Debt Instrument [Line Items]
Credit agreement - term loan description	Each of the Credit Agreements provides that we and lenders representing more than 50% of the facility amount may agree to extend their commitments under such Credit Agreement for two one-year periods beyond the initial termination date. We have the right to terminate, in whole or in part, amounts committed by the lenders under each of the Credit Agreements in excess of any outstanding advances; however, any such terminated commitments may not be reinstated.
Credit agreement - base rate	Advances under these agreements would bear interest, at AT&T's option, either: •at a variable annual rate equal to: (1) the highest of (but not less than zero) (a) the rate of interest announced publicly by Citibank in New York, New York, from time to time, as Citibank's base rate, (b) 0.5% per annum above the federal funds rate, and (c) the London interbank offered rate (or the successor thereto) (“LIBOR”) applicable to dollars for a period of one month plus 1.00%, plus (2) an applicable margin, as set forth in the applicable Credit Agreement (the “Applicable Margin for Base Advances”); or •at a rate equal to: (i) LIBOR (adjusted upwards to reflect any bank reserve costs) for a period of one, two, three or six months, as applicable, plus (ii) an applicable margin, as set forth in the applicable Credit Agreement (the “Applicable Margin for Eurodollar Rate Advances”).
Five Year Credit Agreement [Member] | High Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	7.00%
Five Year Credit Agreement [Member] | Moderate Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	8.00%
Five Year Credit Agreement [Member] | Low Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	10.00%
Five Year Credit Agreement [Member] | Very Low Credit Rating [Member]
Debt Instrument [Line Items]
Credit agreement - commitment fee percentage	12.50%

Fair Value Measurements And D_4

Fair Value Measurements And Disclosure (Narrative) (Details) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value Disclosures [Line Items]
Collateral received from counterparty			$ 44	$ 103
Collateral submitted to counterparty			204	$ 1,675
Collateral contingently payable to the counterparty			35
Debt Instrument, Face Amount			17,235
Available-for-sale Securities			1,444
Fixed income investments - maturities under 1 year			54
Fixed income investments - maturities between 1 to 3 years			172
Fixed income investments - maturities between 3 to 5 years			161
Fixed income investments - maturities for 5 or more years			1,057
Anticipated reclassification of holding gains (losses) during the next 12 months - cash flow hedges			61
Net gains on net investment hedges recognized in accumulated OCI	$ 4
Measurement Input, Entity Credit Risk [Member]
Fair Value Disclosures [Line Items]
Collateral contingently payable to the counterparty			2,678
DIRECTV [Member]
Fair Value Disclosures [Line Items]
Collateral contingently payable to the counterparty			$ 232
WarnerMedia [Member] | Net Investment Hedge [Member]
Fair Value Disclosures [Line Items]
Debt Instrument, Face Amount | €		€ 1,450

Fair Value Measurements And D_5

Fair Value Measurements And Disclosure (Long-Term Debt And Other Financial Instruments) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Notes and debentures		$ 161,109	$ 171,529
Commercial paper		0	3,048
Bank borrowings	[1]	4	4
Carrying Amount [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Notes and debentures	[2]	161,109	171,529
Commercial paper		0	3,048
Bank borrowings		4	4
Investment securities	[3]	3,723	3,409
Fair Value [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Commercial paper		0	3,048
Bank borrowings		4	4
Investment securities	[3]	3,723	3,409
Fair Value [Member] | Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Notes and debentures	[2]	$ 182,124	$ 172,287
[1]	Outstanding balance of short-term credit facility of a foreign subsidiary.
[2]	Includes credit agreement borrowings.
[3]	Excludes investments accounted for under the equity method.

Fair Value Measurements And D_6

Fair Value Measurements And Disclosure (Fair Value Leveling) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities (at fair value)	$ 1,444
Securities Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities (at fair value)	1,444	$ 870
Securities Investment [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	844	1,061
Securities Investment [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	183	256
Fixed Income Equities [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	229	172
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	2
Liability Derivatives		(39)
Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	172	472
Liability Derivatives	(3,187)	(2,563)
Foreign Exchange Contracts [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	89	87
Liability Derivatives		(2)
Interest Rate Locks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	11
Liability Derivatives	(95)
Level 1 [Member] | Securities Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities (at fair value)	0	0
Level 1 [Member] | Securities Investment [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	844	1,061
Level 1 [Member] | Securities Investment [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	183	256
Level 1 [Member] | Fixed Income Equities [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	229	172
Level 1 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0
Liability Derivatives		0
Level 1 [Member] | Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives	0	0
Level 1 [Member] | Foreign Exchange Contracts [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives		0
Level 1 [Member] | Interest Rate Locks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0
Liability Derivatives	0
Level 2 [Member] | Securities Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities (at fair value)	1,444	870
Level 2 [Member] | Securities Investment [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	0	0
Level 2 [Member] | Securities Investment [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	0	0
Level 2 [Member] | Fixed Income Equities [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	0	0
Level 2 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	2
Liability Derivatives		(39)
Level 2 [Member] | Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	172	472
Liability Derivatives	(3,187)	(2,563)
Level 2 [Member] | Foreign Exchange Contracts [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	89	87
Liability Derivatives		(2)
Level 2 [Member] | Interest Rate Locks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	11
Liability Derivatives	(95)
Level 3 [Member] | Securities Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities (at fair value)	0	0
Level 3 [Member] | Securities Investment [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	0	0
Level 3 [Member] | Securities Investment [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	0	0
Level 3 [Member] | Fixed Income Equities [Member] | United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities (at fair value)	0	0
Level 3 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0
Liability Derivatives		0
Level 3 [Member] | Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives	0	0
Level 3 [Member] | Foreign Exchange Contracts [Member] | Non-US [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives		$ 0
Level 3 [Member] | Interest Rate Locks [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0
Liability Derivatives	$ 0

Fair Value Measurement and Disc

Fair Value Measurement and Disclosure (Gains and Losses on Equity Securities) (Details) - Equity Securities [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Total gains (losses) recognized on equity securities	$ 301	$ (130)	$ 326
Gains (Losses) recognized on equity securities sold	100	(10)	47
Unrealized gains (losses) recognized on equity securities held at end of period	$ 201	$ (120)	$ 279

Fair Value Measurements And D_7

Fair Value Measurements And Disclosure (Notional Amount Of Our Outstanding Derivative Positions) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional amount of outstanding derivative positions	$ 46,947	$ 47,769
Interest Rate Swaps [Member]
Derivative [Line Items]
Notional amount of outstanding derivative positions	853	3,483
Cross-Currency Swaps [Member]
Derivative [Line Items]
Notional amount of outstanding derivative positions	42,325	42,192
Interest Rate Locks [Member]
Derivative [Line Items]
Notional amount of outstanding derivative positions	3,500	0
Foreign Exchange Contracts [Member]
Derivative [Line Items]
Notional amount of outstanding derivative positions	$ 269	$ 2,094

Fair Value Measurements And D_8

Fair Value Measurements And Disclosure (Effect Of Derivatives On The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Hedging Relationships [Member] | Interest Rate Swaps [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on interest rate swaps	$ 58	$ (12)	$ (68)
Gain (Loss) on long-term debt	(58)	12	68
Cash Flow Hedging [Member] | Cross-Currency Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated Other Comprehensive Income	(1,066)	(825)	571
Cash Flow Hedging [Member] | Interest Rate Locks [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated Other Comprehensive Income	(84)	0	0
Cash Flow Hedging [Member] | Interest Rate Locks [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Income (expense) reclassified from accumulated Other Comprehensive Income into income	(63)	(58)	(60)
Cash Flow Hedging [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated Other Comprehensive Income	10	51	0
Cash Flow Hedging [Member] | Foreign Exchange Contracts [Member] | Other Income Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Income (expense) reclassified from accumulated Other Comprehensive Income into income	$ 6	$ 39	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Net operating and capital loss carryforwards (tax effected) for federal income tax purposes	$ 693
Net operating and capital loss carryforwards (tax effected) for state income tax purposes	970
Net operating and capital loss carryforwards (tax effected) for foreign income tax purposes	$ 2,948
Expiration year of operating and capital loss carryforwards	2039
Expiration year for credit carryforwards	Dec. 31, 2039
Income Tax Contingency [Line Items]
IRS field examination of tax returns complete through year	2010
All audit periods prior to this year are closed for federal examination purposes	2003
Enactment of the Tax Cuts and Jobs Act, Total		$ (22,211)
Enactment date and measurement period adjustments from the Act	$ 0	(718)	$ (20,271)
Net deposits to various taxing jurisdictions	2,584	2,115
Accrued interest and penalties included in unrecognized tax benefits balance at year end	2,708	2,588
Net interest and penalty expense (benefit) included in income tax expense	267	$ 1,290	$ 107
Federal [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	664
State [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	$ 2,025
Period Start [Member]
Income Tax Contingency [Line Items]
Tax return year(s) subject to resolution with IRS Appeals Division	2003
Period End [Member]
Income Tax Contingency [Line Items]
Tax return year(s) subject to resolution with IRS Appeals Division	2010

Income Taxes (Components Of Def

Income Taxes (Components Of Deferred Tax Liabilities (Assets)) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Depreciation and amortization	$ 44,896	$ 43,105
Licenses and nonamortizable intangibles	17,355	17,561
Employee benefits	(5,143)	(5,366)
Deferred fulfillment costs	3,050	2,679
Net operating loss and other carryforwards	(7,301)	(6,470)
Other - net	1,536	1,651
Subtotal	54,393	53,160
Deferred tax assets valuation allowance	4,941	4,588
Net deferred tax liabilities	59,334	57,748
Noncurrent deferred tax liabilities	59,502	57,859
Less: Noncurrent deferred tax assets	(168)	(111)
Net deferred tax liabilities	$ 59,334	$ 57,748

Income Taxes (Changes In Unreco

Income Taxes (Changes In Unrecognized Tax Benefits Balance For Federal State And Foreign Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Balance at beginning of year	$ 10,358	$ 7,648
Increases for tax positions related to the current year	903	336
Increases for tax positions related to prior years	1,106	2,615
Decreases for tax positions related to prior years	(1,283)	(394)
Lapse of statute of limitations	(32)	(52)
Settlements	(283)	(664)
Current year acquisitions	205	872
Increase Resulting from Foreign Currency Translation	5
Decrease resulting from foreign currency effects		(3)
Balance at end of year	10,979	10,358
Accrued interest and penalties	2,708	2,588
Gross unrecognized income tax benefits	13,687	12,946
Less: Deferred federal and state income tax benefits	(886)	(811)
Less: Tax attributable to timing items included above	(4,320)	(3,430)
Less: UTBs included above that relate to acquired entities that would impact goodwill if recognized	0	(918)
Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year	$ 8,481	$ 7,787

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Current, federal	$ 584	$ 3,258	$ 682
Deferred - net, federal	1,656	277	(17,970)
Total federal income tax	2,240	3,535	(17,288)
Current, state and local	603	513	79
Deferred - net, state and local	144	473	1,041
Total state and local income tax	747	986	1,120
Current, foreign	605	539	471
Deferred - net, foreign	(99)	(140)	989
Total foreign income tax	506	399	1,460
Total	$ 3,493	$ 4,920	$ (14,708)

Income Taxes (Schedule of Incom

Income Taxes (Schedule of Income before Income Tax, Domestic and Foreign) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income (Loss) from Continuing Operations before Income Taxes
U.S. income before income taxes	$ 18,301	$ 25,379	$ 16,438
Foreign income (loss) before income taxes	167	(506)	(1,299)
Income Before Income Taxes	$ 18,468	$ 24,873	$ 15,139

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Income Tax Expense Based On Federal Statutory Rate To Amount Per Effective Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Taxes computed at federal statutory rate	$ 3,878	$ 5,223	$ 5,299
State and local income taxes - net of federal income tax benefit	611	738	509
Enactment date and measurement period adjustments from the Act	0	(718)	(20,271)
Tax on foreign investments	(115)	(466)	73
Noncontrolling interest	(230)	(121)	(133)
Other - net	(651)	264	(185)
Total	$ 3,493	$ 4,920	$ (14,708)
Effective Tax Rate	18.90%	19.80%	(97.20%)
Statutory federal income tax rate	21.00%	21.00%	35.00%

Pension And Postretirement Be_4

Pension And Postretirement Benefits (Narrative) (Details) - USD ($)	3 Months Ended				9 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Measurement Date							Dec. 31, 2019
Preferred equity interest in Mobility									$ 8,803,000,000
Combined net pension and postretirement cost							$ 2,762,000,000		(4,251,000,000)		$ 155,000,000
Increase (decrease) in plan benefit obligations due to change in assumed rates							$ (2,002,000,000)		$ (1,148,000,000)		(1,031,000,000)
Composite rate of compensation increase for determining benefit obligation	3.00%						3.00%		3.00%
Pension Contribution Date							Dec. 31, 2019
Pension Contributions							$ 200,000,000
Benefit cost of the contributory savings plans							793,000,000		$ 724,000,000		703,000,000
Debt-financed shares held by ESOPs (allocated or unallocated)	$ 0						0
Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates						$ 273,000,000
Percentage decrease in the actual long-term rate of return used to report the impact of change on future combined net pension and postretirement cost						(0.50%)
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits							81,000,000		1,000,000
Accumulated benefit obligation for pension plans	$ 58,150,000,000						58,150,000,000		53,963,000,000
Combined net pension and postretirement cost							$ 2,393,000,000		$ (909,000,000)		$ 651,000,000
Discount rate for determining projected benefit obligation	3.40%						3.40%		4.50%		3.80%
Weighted-average interest crediting rate for cash balance	3.30%						3.30%		3.70%		3.50%
Increase (decrease) in plan benefit obligations due to change in assumed rates							$ 8,018,000,000		$ (4,394,000,000)
Increase (decrease) in discount rate over prior year							(1.10%)		0.70%
Long-term rate of return on plan assets							7.00%		7.00%		7.75%
Composite rate of compensation increase for determining benefit obligation	3.00%						3.00%		3.00%		3.00%
Pension Benefit [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates						$ 130,000,000
Long-term rate of return on plan assets						7.00%
Percentage decrease in the actual long-term rate of return used to report the impact of change on future combined net pension and postretirement cost						50.00%
Pension Benefit [Member] | Mortality Assumption Rate Change [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates							$ (147,000,000)		$ (488,000,000)
Pension Benefit [Member] | Service Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.50%	3.90%	4.30%	4.60%			4.10%	[1],[2]	4.20%	[1],[2]	4.60%	[1],[2]
Pension Benefit [Member] | Interest Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.00%	3.20%	3.70%	4.20%			3.50%	[1],[2]	3.80%	[1],[2]	3.60%	[1],[2]
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits							$ 0		$ 1,000,000
Combined net pension and postretirement cost							$ 369,000,000		$ (3,342,000,000)		$ (496,000,000)
Discount rate for determining projected benefit obligation	3.20%						3.20%		4.40%		3.70%
Weighted-average interest crediting rate for cash balance	0.00%						0.00%		0.00%		0.00%
Increase (decrease) in plan benefit obligations due to change in assumed rates							$ 2,399,000,000		$ (1,509,000,000)
Increase (decrease) in discount rate over prior year							(1.20%)		0.70%
Long-term rate of return on plan assets							5.75%		5.75%		5.75%
Composite rate of compensation increase for determining benefit obligation	3.00%						3.00%		3.00%		3.00%
Postretirement Benefit [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Long-term rate of return on plan assets						4.75%
Postretirement Benefit [Member] | Mortality Assumption Rate Change [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates							$ (4,000,000)		$ (61,000,000)
Postretirement Benefit [Member] | Service Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.40%				4.70%		4.40%	[1],[2]	4.30%	[1],[2]	4.60%	[1],[2]
Postretirement Benefit [Member] | Interest Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	2.70%				4.00%		3.70%	[1],[2]	3.60%	[1],[2]	3.40%	[1],[2]
Supplemental Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Combined net pension and postretirement cost							$ 438,000,000		$ 53,000,000
Composite rate of compensation increase for determining benefit obligation	3.20%						3.20%		4.40%
Accumulated benefit obligation	$ 2,605,000,000						$ 2,605,000,000		$ 2,397,000,000
Deferred compensation expense							$ 199,000,000		$ 128,000,000		$ 138,000,000
Administrative Expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated annual health care cost trend rate for prior and current year							2.50%
Administrative Expense [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated annual health care cost trend rate for prior and current year						2.50%
Dental Claims [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated annual health care cost trend rate for prior and current year							3.00%
Dental Claims [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated annual health care cost trend rate for prior and current year						3.00%
Prescription Drug Cost - Eligible Participants [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated annual growth rate for health care cost	4.50%						4.50%
Prescription Drug Cost - Eligible Participants [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates						$ (102,000,000)
Estimated annual growth rate for health care cost						4.00%
Medical Cost - Eligible Participants [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated annual growth rate for health care cost	4.50%						4.50%
Medical Cost - Eligible Participants [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates						$ (102,000,000)
Estimated annual growth rate for health care cost						4.00%
[1]	Weighted-average discount rate for pension benefits in effect from January 1, 2019 through March 31, 2019 was 4.60% for service cost and 4.20% for interest cost, from April 1, 2019 through June 30, 2019 was 4.30% for service cost and 3.70% for interest cost, from July 1, 2019
[2]	Weighted-average discount rate for postretirement benefits in effect from January 1, 2019 through October 1, 2019 was 4.70% for service cost and 4.00% for interest cost, and, from October 2, 2019 through December 31, 2019 was 3.40% for service cost and 2.70% for interest cost.

Pension And Postretirement Be_5

Pension And Postretirement Benefits (Change In The Projected Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	$ 55,439	$ 59,294
Service cost - benefits earned during the period	1,019	1,116	$ 1,128
Interest cost on projected benefit obligation	1,960	2,092	1,936
Amendments	0	50
Actuarial (gain) loss	7,734	(5,046)
Special termination benefits	81	1
Benefits paid	(6,356)	(4,632)
Acquisition	0	2,559
Plan transfers	(4)	5
Benefit obligation at end of year	59,873	55,439	59,294
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year	19,378	24,059
Service cost - benefits earned during the period	71	109	138
Interest cost on projected benefit obligation	675	778	809
Amendments	(4,590)	(1,145)
Actuarial (gain) loss	2,050	(2,815)
Special termination benefits	0	1
Benefits paid	(1,543)	(1,680)
Acquisition	0	71
Plan transfers	0	0
Benefit obligation at end of year	$ 16,041	$ 19,378	$ 24,059

Pension And Postretirement Be_6

Pension And Postretirement Benefits (Change In The Value Of Plan Assets And The Plans' Funded Status) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year		$ 51,681	$ 45,463
Actual return on plan assets		8,207	(1,044)
Benefits paid	[1]	(6,356)	(4,632)
Contributions		2	9,307
Acquisition		0	2,582
Plan transfers		(4)	5
Fair value of plan assets at end of year		53,530	51,681
Unfunded status at end of year	[2]	(6,343)	(3,758)
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year		4,277	5,973
Actual return on plan assets		609	(218)
Benefits paid	[1]	(941)	(1,503)
Contributions		200	25
Acquisition		0	0
Plan transfers		0	0
Fair value of plan assets at end of year		4,145	4,277
Unfunded status at end of year	[2]	$ (11,896)	$ (15,101)
[1]	At our discretion, certain postretirement benefits may be paid from AT&T cash accounts, which does not reduce Voluntary Employee Benefit Association (VEBA) assets. Future benefit payments may be made from VEBA trusts and thus reduce those asset balances.
[2]	Funded status is not indicative of our ability to pay ongoing pension benefits or of our obligation to fund retirement trusts. Required pension funding is determined in accordance with the Employee Retirement Income Security Act of 1974, as amended (ERISA) and applicable regulations.

Pension And Postretirement Be_7

Pension And Postretirement Benefits (Employee Benefit Obligation Amounts Recognized) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Current portion of employee benefit obligation	[1]	$ 0	$ 0
Employee benefit obligation	[2]	(6,343)	(3,758)
Net amount recognized		(6,343)	(3,758)
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Current portion of employee benefit obligation	[1]	(1,365)	(1,464)
Employee benefit obligation	[2]	(10,531)	(13,637)
Net amount recognized		$ (11,896)	$ (15,101)
[1]	Included in “Accounts payable and accrued liabilities.”
[2]	Included in “Postemployment benefit obligation.”

Pension And Postretirement Be_8

Pension And Postretirement Benefits (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit (credit) cost	$ 2,762	$ (4,251)	$ 155
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	1,019	1,116	1,128
Interest cost on projected benefit obligation	1,960	2,092	1,936
Expected return on assets	(3,561)	(3,190)	(3,134)
Amortization of prior service cost (credit)	(113)	(115)	(123)
Actuarial (gain) loss	3,088	(812)	844
Net periodic benefit (credit) cost	2,393	(909)	651
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	71	109	138
Interest cost on projected benefit obligation	675	778	809
Expected return on assets	(227)	(304)	(319)
Amortization of prior service cost (credit)	(1,820)	(1,635)	(1,466)
Actuarial (gain) loss	1,670	(2,290)	342
Net periodic benefit (credit) cost	$ 369	$ (3,342)	$ (496)

Pension And Postretirement Be_9

Pension And Postretirement Benefits (Other Changes Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Prior service (cost) credit		$ 3,457	$ 830	$ 1,083
Amortization of prior service cost (credit)		(1,459)	(1,322)	(988)
Adoption of ASU 2018-02	[1]	0
ASU 2018-02 [Member]
Defined Benefit Plan Disclosure [Line Items]
Adoption of ASU 2018-02			1,529
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance at beginning of year		447	571	575
Prior service (cost) credit		0	(37)	(30)
Amortization of prior service cost (credit)		(86)	(87)	(76)
Total recognized in other comprehensive (income) loss		(86)	(124)	(106)
Balance at end of year		361	447	571
Pension Benefit [Member] | ASU 2018-02 [Member]
Defined Benefit Plan Disclosure [Line Items]
Adoption of ASU 2018-02		0	0	102
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance at beginning of year		6,086	6,456	5,089
Prior service (cost) credit		3,457	864	1,120
Amortization of prior service cost (credit)		(1,372)	(1,234)	(907)
Total recognized in other comprehensive (income) loss		2,085	(370)	213
Balance at end of year		8,171	6,086	6,456
Postretirement Benefit [Member] | ASU 2018-02 [Member]
Defined Benefit Plan Disclosure [Line Items]
Adoption of ASU 2018-02		$ 0	$ 0	$ 1,154
[1]	With the adoption of ASU 2016-01, the unrealized (gains) losses on our equity investments are reclassified to retained earnings (see Note 1).

Pension and Postretirement B_10

Pension and Postretirement Benefits (Weighted Average Assumptions - Projected Benefit Obligation And Net Pension And Postemployment Benefit Cost) (Details)	3 Months Ended				9 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Composite rate of compensation increase for determining benefit obligation	3.00%					3.00%		3.00%
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate for determining projected benefit obligation at December 31	3.40%					3.40%		4.50%		3.80%
Weighted-average interest crediting rate for cash balance	3.30%					3.30%		3.70%		3.50%
Long-term rate of return on plan assets						7.00%		7.00%		7.75%
Composite rate of compensation increase for determining benefit obligation	3.00%					3.00%		3.00%		3.00%
Composite rate of compensation increase for determining net cost (benefit)						3.00%		3.00%		3.00%
Pension Benefit [Member] | Service Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.50%	3.90%	4.30%	4.60%		4.10%	[1],[2]	4.20%	[1],[2]	4.60%	[1],[2]
Pension Benefit [Member] | Interest Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.00%	3.20%	3.70%	4.20%		3.50%	[1],[2]	3.80%	[1],[2]	3.60%	[1],[2]
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate for determining projected benefit obligation at December 31	3.20%					3.20%		4.40%		3.70%
Weighted-average interest crediting rate for cash balance	0.00%					0.00%		0.00%		0.00%
Long-term rate of return on plan assets						5.75%		5.75%		5.75%
Composite rate of compensation increase for determining benefit obligation	3.00%					3.00%		3.00%		3.00%
Composite rate of compensation increase for determining net cost (benefit)						3.00%		3.00%		3.00%
Postretirement Benefit [Member] | Service Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.40%				4.70%	4.40%	[1],[2]	4.30%	[1],[2]	4.60%	[1],[2]
Postretirement Benefit [Member] | Interest Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	2.70%				4.00%	3.70%	[1],[2]	3.60%	[1],[2]	3.40%	[1],[2]
[1]	Weighted-average discount rate for pension benefits in effect from January 1, 2019 through March 31, 2019 was 4.60% for service cost and 4.20% for interest cost, from April 1, 2019 through June 30, 2019 was 4.30% for service cost and 3.70% for interest cost, from July 1, 2019
[2]	Weighted-average discount rate for postretirement benefits in effect from January 1, 2019 through October 1, 2019 was 4.70% for service cost and 4.00% for interest cost, and, from October 2, 2019 through December 31, 2019 was 3.40% for service cost and 2.70% for interest cost.

Pension And Postretirement B_11

Pension And Postretirement Benefits (Schedule Of Defined Benefit Plan Targeted And Actual Plan Asset Allocations) (Details)	Dec. 31, 2019	Dec. 31, 2018
Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	100.00%	100.00%
Aggregate percentage of the fair value of investments to the fair value of total plan assets held as of the measurement date	17.00%
Pension Assets [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	17.00%	16.00%
Pension Assets [Member] | Domestic Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	15.00%	15.00%
Pension Assets [Member] | Domestic Equity Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	25.00%	25.00%
Pension Assets [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	12.00%	12.00%
Pension Assets [Member] | International Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	7.00%	7.00%
Pension Assets [Member] | International Equity Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	17.00%	17.00%
Pension Assets [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	35.00%	37.00%
Pension Assets [Member] | Fixed Income Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	29.00%	29.00%
Pension Assets [Member] | Fixed Income Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	39.00%	39.00%
Pension Assets [Member] | Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	9.00%	9.00%
Pension Assets [Member] | Real Assets [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	4.00%	4.00%
Pension Assets [Member] | Real Assets [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	14.00%	14.00%
Pension Assets [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	8.00%	8.00%
Pension Assets [Member] | Private Equity [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	2.00%	2.00%
Pension Assets [Member] | Private Equity [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	12.00%	12.00%
Pension Assets [Member] | Preferred Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	17.00%	18.00%
Pension Assets [Member] | Preferred Interest [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	13.00%	13.00%
Pension Assets [Member] | Preferred Interest [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	23.00%	23.00%
Pension Assets [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	2.00%	0.00%
Pension Assets [Member] | Other [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Pension Assets [Member] | Other [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	5.00%	5.00%
Postretirement Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	100.00%	100.00%
Aggregate percentage of the fair value of investments to the fair value of total plan assets held as of the measurement date	3.00%
Postretirement Assets [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	20.00%	25.00%
Postretirement Assets [Member] | Domestic Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	15.00%	15.00%
Postretirement Assets [Member] | Domestic Equity Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	25.00%	25.00%
Postretirement Assets [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	12.00%	18.00%
Postretirement Assets [Member] | International Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	8.00%	8.00%
Postretirement Assets [Member] | International Equity Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	18.00%	18.00%
Postretirement Assets [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	52.00%	39.00%
Postretirement Assets [Member] | Fixed Income Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	47.00%	47.00%
Postretirement Assets [Member] | Fixed Income Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	57.00%	57.00%
Postretirement Assets [Member] | Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	1.00%	1.00%
Postretirement Assets [Member] | Real Assets [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Postretirement Assets [Member] | Real Assets [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	6.00%	6.00%
Postretirement Assets [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	2.00%	2.00%
Postretirement Assets [Member] | Private Equity [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Postretirement Assets [Member] | Private Equity [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	7.00%	7.00%
Postretirement Assets [Member] | Preferred Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Postretirement Assets [Member] | Preferred Interest [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Postretirement Assets [Member] | Preferred Interest [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Postretirement Assets [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	13.00%	15.00%
Postretirement Assets [Member] | Other [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	9.00%	9.00%
Postretirement Assets [Member] | Other [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	19.00%	19.00%

Pension And Postretirement B_12

Pension And Postretirement Benefits (Schedule Of Fair Value Of Pension And Postretirement Assets And Liabilities By Level) (Details) - USD ($) $ in Millions		Dec. 31, 2019		Dec. 31, 2018
Pension Assets And Liabilities Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-interest bearing cash		$ 85		$ 52
Interest bearing cash		529		208
Foreign currency contracts		5		5
Equity securities - Domestic equities		8,072		6,913
Equity securities - International equities		3,946		3,602
Prefered Interest		8,806		8,749
Fixed income securities - Corporate bonds and other instruments		10,473		10,723
Fixed income securities - Government and municipal bonds		6,172		6,221
Fixed income securities - Mortgage-backed securities		524		382
Real estate and real assets		2,817		2,579
Securities lending collateral		1,761		1,478
Purchased options, futures, and swaps				3
Receivable for variation margin		5		19
Assets at fair value		43,195		40,934
Investments sold short and other liabilities at fair value		(515)		(663)
Total plan net assets at fair value		42,680		40,271
Assets held at net asset value practical expedient
Private equity funds		4,544		4,384
Real estate funds		2,062		2,162
Commingled funds		5,710		5,740
Total assets held at net asset value practical expedient		12,316		12,286
Other assets (liabilities)	[1]	(1,466)		(876)
Total Plan Net Assets		53,530		51,681
Pension Assets And Liabilities Fair Value [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-interest bearing cash		85		52
Interest bearing cash		529		167
Foreign currency contracts		0		0
Equity securities - Domestic equities		8,068		6,912
Equity securities - International equities		3,929		3,594
Prefered Interest		0		0
Fixed income securities - Corporate bonds and other instruments		0		0
Fixed income securities - Government and municipal bonds		49		51
Fixed income securities - Mortgage-backed securities		0		0
Real estate and real assets		0		0
Securities lending collateral		103		12
Purchased options, futures, and swaps				0
Receivable for variation margin		5		19
Assets at fair value		12,768		10,807
Investments sold short and other liabilities at fair value		(513)		(657)
Total plan net assets at fair value		12,255		10,150
Pension Assets And Liabilities Fair Value [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-interest bearing cash		0		0
Interest bearing cash		0		41
Foreign currency contracts		5		5
Equity securities - Domestic equities		0		0
Equity securities - International equities		11		8
Prefered Interest		0		0
Fixed income securities - Corporate bonds and other instruments		10,469		10,719
Fixed income securities - Government and municipal bonds		6,123		6,170
Fixed income securities - Mortgage-backed securities		522		382
Real estate and real assets		0		0
Securities lending collateral		1,658		1,466
Purchased options, futures, and swaps				3
Receivable for variation margin		0		0
Assets at fair value		18,788		18,794
Investments sold short and other liabilities at fair value		(2)		(6)
Total plan net assets at fair value		18,786		18,788
Pension Assets And Liabilities Fair Value [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-interest bearing cash		0		0
Interest bearing cash		0		0
Foreign currency contracts		0		0
Equity securities - Domestic equities		4		1
Equity securities - International equities		6		0
Prefered Interest		8,806		8,749
Fixed income securities - Corporate bonds and other instruments		4		4
Fixed income securities - Government and municipal bonds		0		0
Fixed income securities - Mortgage-backed securities		2		0
Real estate and real assets		2,817		2,579
Securities lending collateral		0		0
Purchased options, futures, and swaps				0
Receivable for variation margin		0		0
Assets at fair value		11,639		11,333
Investments sold short and other liabilities at fair value		0		0
Total plan net assets at fair value		11,639		11,333
Postretirement Assets And Liabilities Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest bearing cash		549		669
Equity securities - Domestic equities		438		753
Equity securities - International equities		265		542
Fixed income securities - Corporate bonds and other instruments		530		620
Fixed income securities - Government and municipal bonds		189		380
Fixed income securities - Mortgage-backed securities		294		283
Securities lending collateral		36		63
Assets at fair value		2,301		3,310
Securities lending payable and other liabilities		(36)		(74)
Total plan net assets at fair value		2,265		3,236
Assets held at net asset value practical expedient
Private equity funds		66		79
Real estate funds		27		36
Commingled funds		1,797		973
Total assets held at net asset value practical expedient		1,890		1,088
Other assets (liabilities)		(10)	[1]	(47)	[2]
Total Plan Net Assets		4,145		4,277
Postretirement Assets And Liabilities Fair Value [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest bearing cash		248		45
Equity securities - Domestic equities		438		745
Equity securities - International equities		265		541
Fixed income securities - Corporate bonds and other instruments		7		7
Fixed income securities - Government and municipal bonds		6		2
Fixed income securities - Mortgage-backed securities		0		0
Securities lending collateral		0		0
Assets at fair value		964		1,340
Securities lending payable and other liabilities		0		0
Total plan net assets at fair value		964		1,340
Postretirement Assets And Liabilities Fair Value [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest bearing cash		301		624
Equity securities - Domestic equities		0		8
Equity securities - International equities		0		0
Fixed income securities - Corporate bonds and other instruments		492		602
Fixed income securities - Government and municipal bonds		182		377
Fixed income securities - Mortgage-backed securities		294		283
Securities lending collateral		36		63
Assets at fair value		1,305		1,957
Securities lending payable and other liabilities		(36)		(74)
Total plan net assets at fair value		1,269		1,883
Postretirement Assets And Liabilities Fair Value [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest bearing cash		0		0
Equity securities - Domestic equities		0		0
Equity securities - International equities		0		1
Fixed income securities - Corporate bonds and other instruments		31		11
Fixed income securities - Government and municipal bonds		1		1
Fixed income securities - Mortgage-backed securities		0		0
Securities lending collateral		0		0
Assets at fair value		32		13
Securities lending payable and other liabilities		0		0
Total plan net assets at fair value		$ 32		$ 13
[1]	Other assets (liabilities) include amounts receivable, accounts payable and net adjustment for securities lending payable.
[2]	Other assets (liabilities) include amounts receivable and accounts payable.

Pension And Postretirement B_13

Pension And Postretirement Benefits (Fair Value Assets Measured On Recurring Basis Unobservable Input (Level 3) Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	$ 11,333	$ 2,293
Realized gains (losses)	64	120
Unrealized gains (losses)	103	(239)
Transfers in	147	9,425
Transfers out	(6)	(5)
Purchases	235	93
Sales	(237)	(354)
Balance, end of year	11,639	11,333
Pension Assets [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	8,750	4
Realized gains (losses)	0	0
Unrealized gains (losses)	58	(408)
Transfers in	8	9,158
Transfers out	0	(4)
Purchases	0	0
Sales	0	0
Balance, end of year	8,816	8,750
Pension Assets [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	4	2
Realized gains (losses)	0	0
Unrealized gains (losses)	0	(1)
Transfers in	5	1
Transfers out	(6)	(1)
Purchases	7	8
Sales	(4)	(5)
Balance, end of year	6	4
Pension Assets [Member] | Real Estate And Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	2,579	2,287
Realized gains (losses)	64	120
Unrealized gains (losses)	45	170
Transfers in	134	266
Transfers out	0	0
Purchases	228	85
Sales	(233)	(349)
Balance, end of year	2,817	2,579
Postretirement Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	13	5
Transfers in	28	9
Transfers out	(1)	(1)
Purchases		1
Sales	(8)	(1)
Balance, end of year	32	13
Postretirement Assets [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	1	0
Transfers in	0	1
Transfers out	0	0
Purchases		0
Sales	(1)	0
Balance, end of year	0	1
Postretirement Assets [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	12	5
Transfers in	28	8
Transfers out	(1)	(1)
Purchases		1
Sales	(7)	(1)
Balance, end of year	32	12
Postretirement Assets [Member] | Real Estate And Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, beginning of year	0	0
Transfers in	0	0
Transfers out	0	0
Purchases		0
Sales	0	0
Balance, end of year	$ 0	$ 0

Pension And Postretirement B_14

Pension And Postretirement Benefits (Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2019USD ($)
Pension Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future benefit payments under our pension and postretirement plans - 2020	$ 5,540
Estimated future benefit payments under our pension and postretirement plans - 2021	4,471
Estimated future benefit payments under our pension and postretirement plans - 2022	4,362
Estimated future benefit payments under our pension and postretirement plans - 2023	4,272
Estimated future benefit payments under our pension and postretirement plans - 2024	4,174
Estimated future benefit payments under our pension and postretirement plans - Years 2025 - 2029	19,965
Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future benefit payments under our pension and postretirement plans - 2020	1,539
Estimated future benefit payments under our pension and postretirement plans - 2021	1,441
Estimated future benefit payments under our pension and postretirement plans - 2022	1,343
Estimated future benefit payments under our pension and postretirement plans - 2023	1,258
Estimated future benefit payments under our pension and postretirement plans - 2024	1,015
Estimated future benefit payments under our pension and postretirement plans - Years 2025 - 2029	$ 4,307

Share-Based Payments (Narrative

Share-Based Payments (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-Based Payment [Line Items]
Number of authorized shares of common stock for share-based payment arrangements (in shares)	293
Total unrecognized compensation cost related to nonvested share-based payment arrangements granted	$ 693
Weighted-average period to recognize the cost (years) - nonvested units	2 years 2 months 15 days
Total fair value of shares vested during the year - nonvested units	$ 798	$ 766	$ 473
Cash proceeds from exercise of stock options	$ 446	$ 361	$ 33
Stock Options Under Deferred Compensation Plan [Member] | Time Warner Inc. [Member]
Share-Based Payment [Line Items]
Vesting period	1 year
Performance Stock Units [Member]
Share-Based Payment [Line Items]
Vesting period	3 years
Restricted Stock Units | Minimum Vesting Period [Member]
Share-Based Payment [Line Items]
Vesting period	4 years
Restricted Stock Units | Minimum Vesting Period [Member] | Time Warner Inc. [Member]
Share-Based Payment [Line Items]
Vesting period	1 year
Restricted Stock Units | Maximum Vesting Period [Member]
Share-Based Payment [Line Items]
Vesting period	5 years
Restricted Stock Units | Maximum Vesting Period [Member] | Time Warner Inc. [Member]
Share-Based Payment [Line Items]
Vesting period	4 years
Other Nonvested Stock Units [Member]
Share-Based Payment [Line Items]
Vesting period	3 years

Share-Based Payments (Compensat

Share-Based Payments (Compensation Cost And Valuation Assumption) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-Based Payment
Performance stock units	$ 544	$ 301	$ 395
Restricted stock and stock units	273	153	90
Other nonvested stock units	7	4	(5)
Other	(5)	5	0
Total	819	463	480
Income tax benefit	$ 202	$ 114	$ 184

Share-Based Payments (Summary O

Share-Based Payments (Summary Of Nonvested Stock Units Activity) (Details) shares in Millions	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Share-Based Payment
Beginning balance - outstanding nonvested units | shares	39
Granted - nonvested units (period) | shares	27
Vested - nonvested units (period) | shares	(21)
Forfeited - nonvested units (period) | shares	(3)
Ending balance - outstanding nonvested units | shares	42
Beginning balance - weighted average exercise price of outstanding nonvested units | $ / shares	$ 38.44
Weighted average exercise price - granted - nonvested units | $ / shares	31.18
Weighted average exercise price - vested - nonvested units | $ / shares	39.03
Weighted average exercise price - forfeited nonvested units | $ / shares	34.26
Ending balance - weighted average exercise price of nonvested units | $ / shares	$ 33.80

Stockholder Equity (Narrative)

Stockholder Equity (Narrative) (Details) $ / shares in Units, $ in Millions	1 Months Ended			12 Months Ended
	Feb. 29, 2020$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017$ / shares	Feb. 29, 2020€ / sharesshares	Sep. 30, 2019USD ($)
Class of Stock [Line Items]
Common stock, authorized (in shares)		14,000,000,000	14,000,000,000	14,000,000,000	14,000,000,000
Common stock, par value | $ / shares		$ 1	$ 1	$ 1	$ 1
Common Stock, quarterly dividend declared per common shares (per share) | $ / shares		$ 0.52	$ 0.51	$ 2.05	$ 2.01	$ 1.97
Preferred stock, authorized (in shares)		10,000,000		10,000,000
Preferred stock, outstanding (in shares)		48,000	0	48,000	0
Preferred stock, par value | $ / shares		$ 1		$ 1
Preferred stock, value, issued | $		$ 0	$ 0	$ 0	$ 0
Preferred stock, issued (in shares)		48,000	0	48,000	0
Preferred stock, dividend rate				5.00%
Preferred Stock, quarterly dividend declared | $		$ 8
Tower Holdings [Member]
Minority Interest [Line Items]
Fixed Future Purchase Option Price | $				$ 6,000
Puerto Rico and U.S. Virgin Islands Wireline and Wireless Operations [Member]
Minority Interest [Line Items]
Preferred interest, description				In December 2019, we issued $1,950 nonconvertible cumulative preferred interests in a subsidiary (PR Holdings) that holds notes secured by the proceeds from the agreement to sell wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands.
Preferred interest issued | $		$ 1,950		$ 1,950
Preferred interest dividend requirements				The membership interests in PR Holdings consist of (1) common interests, which are held by consolidated subsidiaries of AT&T, and (2) preferred interests (PR preferred interests). The PR preferred interests pay an initial preferred distribution at an annual rate of 4.75%. Distributions are paid quarterly, subject to declaration, and reset every five years. Any failure to declare or pay distributions on the PR preferred interests would not impose any limitation on cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares.
Preferred interest, redemption terms				The holders of the PR preferred interests have the option to require redemption upon the occurrence of certain contingent events, such as the failure of AT&T to pay the preferred distribution for two or more periods or to meet certain other requirements, including a minimum AT&T credit rating. If notice is given upon such an event, all other holders of equal or more subordinate classes of membership interests in PR Holdings are entitled to receive the same form of consideration payable to the holders of the preferred interests, resulting in a deemed liquidation for accounting purposes.
Preferred interest, call or exercise features				We can call the PR preferred interests at the issue price beginning five years from the issuance date or upon the closing or termination of the sale of the underlying assets.
Common Class A [Member] | Stock Repurchase Program March 2014 [Member]
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		300,000,000		300,000,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		300,000,000		300,000,000
Common Class A [Member] | Stock Repurchase Program March 2013 [Member]
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		300,000,000		300,000,000
Treasury Stock, Shares, Acquired				56,000,000
Treasury Stock, Value, Acquired, Cost Method | $				$ 2,135
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		19,000,000		19,000,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)		48,000	0	48,000	0
Preferred stock, dividend payment terms				So long as the quarterly preferred dividends are declared and paid on a timely basis on each series of preferred shares, there are no limitations on our ability to declare a dividend on or repurchase AT&T common shares.
Preferred stock, call or exercise features				The preferred shares are optionally redeemable by AT&T at the liquidation price on or after five years from the issuance date, or upon certain other contingent events.
Preferred stock, liquidation preference per share | $ / shares		$ 25,000		$ 25,000
Series A Preferred Stock [Member] | Mobility II, LLC
Minority Interest [Line Items]
Preferred interest distributions | $				$ 560
Preferred interest dividend requirements				So long as the distributions are declared and paid, the terms of the Mobility preferred equity interests will not impose any limitations on cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares.
Preferred interest, redemption terms				The price at which a put option or a redemption option can be exercised is the greater of (1) the market value of the interests as of the last date of the quarter preceding the date of the exercise of a put or redemption option and (2) the sum of (a) twenty-five dollars ($8,000 in the aggregate) plus (b) any accrued and unpaid distributions. The redemption price may be paid with cash, AT&T common stock, or a combination of cash and AT&T common stock, at Mobility II’s sole election. In no event shall Mobility II be required to deliver more than 250 million shares of AT&T common stock to settle put and redemption options.
Preferred interest, call or exercise features				A holder of the Mobility preferred interests may put the interests to Mobility II on or after the earliest of certain events or September 9, 2020. Mobility II may redeem the interests upon a change in control of Mobility II or on or after September 9, 2022. When either options arise due to a passage of time, that option may be exercised only during certain periods.
Preferred interest, securities issued (in shares)		320,000,000		320,000,000
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend payment terms	So long as the quarterly preferred dividends are declared and paid on a timely basis on each series of preferred shares, there are no limitations on our ability to declare a dividend on or repurchase AT&T common shares.
Series B Preferred Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Preferred stock, issued (in shares)	20,000						20,000
Preferred stock, redemption terms	The preferred shares are optionally redeemable by AT&T on or after five years from the issuance date, or upon certain other contingent events.
Preferred stock, liquidation preference per share | € / shares							€ 100,000
Preferred stock, dividend rate	2.875%
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend payment terms	So long as the quarterly preferred dividends are declared and paid on a timely basis on each series of preferred shares, there are no limitations on our ability to declare a dividend on or repurchase AT&T common shares.
Series C Preferred Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Preferred stock, issued (in shares)	70,000						70,000
Preferred stock, redemption terms	The preferred shares are optionally redeemable by AT&T on or after five years from the issuance date, or upon certain other contingent events.
Preferred stock, liquidation preference per share | $ / shares	$ 25,000
Preferred stock, dividend rate	4.75%
Preferred Class A [Member] | Tower Holdings [Member]
Minority Interest [Line Items]
Preferred interest issued | $		$ 6,000		$ 6,000
Preferred interest dividend requirements				The membership interests in Tower Holdings consist of (1) common interests, which are held by a consolidated subsidiary of AT&T, and (2) two series of preferred interests (collectively the “Tower preferred interests”). The September series (Class A-1) of the preferred interests totals $1,500 and pays an initial preferred distribution of 5.0%, and the December series (Class A-2) totals $4,500 and pays an initial preferred distribution of 4.75%. Distributions are paid quarterly, subject to declaration, and reset every five years. Any failure to declare or pay distributions on the Tower preferred interests would not impose any limitation on cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares.
Preferred interest, redemption terms				The holders of the Tower preferred interests have the option to require redemption upon the occurrence of certain contingent events, such as the failure of AT&T to pay the preferred distribution for two or more periods or to meet certain other requirements, including a minimum credit rating. If notice is given upon such an event, all other holders of equal or more subordinate classes of membership interests in Tower Holdings are entitled to receive the same form of consideration payable to the holders of the preferred interests, resulting in a deemed liquidation for accounting purposes.
Preferred interest, call or exercise features				We can call the Tower preferred interests at the issue price beginning five years from the issuance date or upon the receipt of proceeds from the sale of the underlying assets.
Class A-1 [Member] | Tower Holdings [Member]
Minority Interest [Line Items]
Preferred interest issued | $								$ 1,500
Preferred interest dividend requirements				The September series (Class A-1) of the preferred interests totals $1,500 and pays an initial preferred distribution of 5.0%
Class A-2 [Member] | Tower Holdings [Member]
Minority Interest [Line Items]
Preferred interest issued | $		$ 4,500		$ 4,500
Preferred interest dividend requirements				the December series (Class A-2) totals $4,500 and pays an initial preferred distribution of 4.75%

Sale Of Receivables (Narrative)

Sale Of Receivables (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts payable and accrued liabilities	$ 45,956	$ 43,184
Guarantee Obligations [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts payable and accrued liabilities	148	196
Guarantee Obligation	384	439
Other Assets [Member] | Deferred Purchase Price [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other Assets	2,336	2,370
Other Current Assets [Member] | Deferred Purchase Price [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other Assets	1,569	$ 1,448
WarnerMedia [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement Amount With Purchaser To Transfer Financial Assets Accounted For As Sales	4,300
Pledged Assets, Not Separately Reported, Finance Receivables	$ 3,324

Sale Of Equipment Installment R

Sale Of Equipment Installment Receivables (Equipment Installment and WarnerMedia Programs) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding portfolio of receivables derecognized from our consolidated balance sheets	$ 9,713	$ 9,065
Cash proceeds received on finance receivables, net of remittances	7,211	6,508
Equipment Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross receivables:	4,576	5,994
Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	2,467	3,457
Trade receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	477	438
Other Noncurrent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other Assets	1,632	2,099
WarnerMedia [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross receivables:	3,324	0
Outstanding portfolio of receivables derecognized from our consolidated balance sheets	4,300	0
Cash proceeds received on finance receivables, net of remittances	4,300	0
WarnerMedia [Member] | Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	0	0
WarnerMedia [Member] | Trade receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	2,809	0
WarnerMedia [Member] | Other Noncurrent Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other Assets	$ 515	$ 0

Sale Of Receivables (Finance Re

Sale Of Receivables (Finance Receivables) (Details) - Finance Receivables [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross receivables sold	$ 9,921	$ 9,391	$ 8,058
Net receivables sold	9,483	8,871	7,388
Cash proceeds received	8,189	7,488	5,623
Deferred purchase price recorded	1,451	1,578	2,077
Guarantee obligation recorded	$ 341	$ 361	$ 215

Sale Of Receivables (Finance _2

Sale Of Receivables (Finance Receivables Repurchased) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Assets [Abstract]
Fair value of repurchased receivables		$ 1,418	$ 1,480	$ 1,699
Carrying value of deferred purchase price		1,350	1,393	1,524
Gain on repurchases	[1]	$ 68	$ 87	$ 175
[1]	These gains are included in “Selling, general and administrative” in the consolidated statements of income.

Sale of Equipment Installment_2

Sale of Equipment Installment Receivables (Summary of WarnerMedia Receivables Sold) (Details) - WarnerMedia [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Transfer Of Financial Assets Accounted For As Sales [Line Items]
Gross receivables sold/cash proceeds received	[1]	$ 11,989	$ 0	$ 0
Collections reinvested under revolving agreement		7,689	0	0
Net cash proceeds received (remitted)		4,300	0	0
Net receivables sold	[2]	11,604	0	0
Guarantee obligation recorded		530	$ 0	$ 0
Initial sale of receivables		$ 4,300
[1]	Includes initial sale of receivables of $ 4,300 for the year ended December 31, 2019.
[2]	Receivables net of allowance, return and incentive reserves and imputed interest.

Tower Transaction (Narrative) (

Tower Transaction (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Other Liabilities [Line Items]
Property, Plant and Equipment - Net	$ 130,128	$ 131,473	$ 125,222
Depreciation expense	$ 20,285	20,083	19,761
Crown Castle International [Member]
Other Liabilities [Line Items]
Number Of Towers Subject To Failed Sale-Leaseback	9,048
Number of towers subject to disposition (as shown)	627
Cash from failed sale-leaseback (in millions U.S. dollars)	$ 4,827
Term of lease	28 years
Approximate fixed future purchase option price on failed sale-leaseback (in millions U.S. dollars)	$ 4,200
Minimum Leaseback Term	10 years
Property, Plant and Equipment - Net	$ 804	843
Depreciation expense	$ 39	$ 39	$ 39
Approximate annual interest rate - financing obligation (as shown)	3.90%
Lease payments	$ 244
Minimum lease payments - 2020	248
Minimum lease payments - 2021	253
Minimum lease payments - 2022	258
Minimum lease payments - 2023	264
Minimum lease payments - 2024	269
Minimum lease payments - thereafter	$ 1,427

FirstNet (Narrative) (Details)

FirstNet (Narrative) (Details) - First Responder Network Authority [Member] $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Spectrum Licenses [Member]
Government Contracts Subject to Renegotiation [Line Items]
Estimated Network Reinvestment	After FirstNet’s operating expenses are paid, we anticipate that the remaining amount, expected to be in the $15,000 range, will be reinvested into the network.
Spectrum Licenses [Member] | Minimum [Member]
Government Contracts Subject to Renegotiation [Line Items]
First Responder Network Authority Operating Expenses	$ 75
Spectrum Licenses [Member] | Maximum [Member]
Government Contracts Subject to Renegotiation [Line Items]
First Responder Network Authority Operating Expenses	100
First Responder Network Authority Operating Expenses Adjusted for Inflation	3,000
FirstNet [Member]
Government Contracts Subject to Renegotiation [Line Items]
Refunds Due under Government Contracts	6,500
Refunds received under Gov't Contract	$ 3,372
Number of jurisdictions opted-in to the program	56
Term of Contract	25 years
Sustainability Payment Commitment, Amount	$ 18,000
Sustainability Payment, Amount	360
Contractual Obligation, Fiscal Year Maturity [Abstract]
Future Sustainability Payments Due in 2020	120
Future Sustainability Payments Due in 2021	120
Future Sustainability Payments Due in 2022	195
Future Sustainability Payments Due in 2023	195
Future Sustainability Payments Due in 2024	195
Future Sustainability Payments Due 2025 and thereafter	$ 16,815
FirstNet [Member] | United States [Member]
Government Contracts Subject to Renegotiation [Line Items]
Number of jurisdictions opted-in to the program	50
FirstNet [Member] | District of Columbia [Member]
Government Contracts Subject to Renegotiation [Line Items]
Number of jurisdictions opted-in to the program	1
FirstNet [Member] | United States Territories [Member]
Government Contracts Subject to Renegotiation [Line Items]
Number of jurisdictions opted-in to the program	5

Contingent Liabilities (Narrati

Contingent Liabilities (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Contingent Liabilities
Contractual purchase obligations for 2020	$ 16,590
Contractual purchase obligations for 2021 and 2022	21,121
Contractual purchase obligations for 2023 and 2024	11,153
Contractual purchase obligations for years 2025 and thereafter	$ 18,943

Additional Financial Informat_3

Additional Financial Information (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jan. 31, 2020
Concentration Risk [Line Items]
Percentage of employees represented by CWA, IBEW, or other unions	40%
Subsequent Event [Member]
Concentration Risk [Line Items]
Approximate number of persons employed at a point in time				246,000
Vendor Financing Program [Member]
Additional Financial Information [Line Items]
Noncash Investing Activities	$ 2,632	$ 2,162	$ 1,000
Workforce Subject to Collective Bargaining Arrangements [Member]
Concentration Risk [Line Items]
Number of employees under contracts where union may call a work stoppage	7,000
Workforce Subject to Collective Bargaining Arrangements [Member] | West Wireline [Member]
Concentration Risk [Line Items]
Number of employees under contracts where union may call a work stoppage	13,000
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member]
Concentration Risk [Line Items]
Relevant union contract expiration year	2020
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year [Member] | West Wireline [Member]
Concentration Risk [Line Items]
Relevant union contract expiration year	April 2020

Additional Financial Informat_4

Additional Financial Information (Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Additional Financial Information [Abstract]
Accounts payable	$ 29,640	$ 27,018
Accrued payroll and commissions	3,126	3,379
Current portion of employee benefit obligation	1,528	1,464
Accrued interest	2,498	2,557
Other	9,164	8,766
Total accounts payable and accrued liabilities	$ 45,956	$ 43,184

Additional Financial Informat_5

Additional Financial Information (Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Additional Financial Information [Abstract]
Advertising expense	$ 6,121	$ 5,100	$ 3,772
Interest expense incurred	8,622	8,450	7,203
Capitalized interest	(200)	(493)	(903)
Total interest expense	$ 8,422	$ 7,957	$ 6,300

Additional Financial Informat_6

Additional Financial Information (Cash and Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 12,130	$ 5,204	$ 50,498	$ 5,788
Restricted cash in Other current assets	69	61	6	7
Restricted cash in Other Assets	96	135	428	140
Cash and cash equivalents and restricted cash	$ 12,295	$ 5,400	$ 50,932	$ 5,935

Additional Financial Informat_7

Additional Financial Information (Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Additional Financial Information [Abstract]
Interest	$ 8,693	$ 8,818	$ 6,622
Income taxes, net of refunds	$ 1,421	$ (354)	$ 2,006

Additional Financial Informat_8

Additional Financial Information (Consolidated Statements Of Cash Flows Operating Leases) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Cash Paid for Amounts Included in the Measurement of Lease Liabilities [Abstract]
Operating cash flows from operating leases	$ 4,583
Operating lease right-of-use assets obtained in exchange for new operating lease obligations	$ 7,818

Quarterly Financial Informati_3

Quarterly Financial Information (Unaudited) (Quarterly Financial Results) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information (Unaudited)
Total operating revenues	$ 46,821	[1],[2]	$ 44,588	[1]	$ 44,957	[1]	$ 44,827	[1]	$ 47,993	[1]	$ 45,739	[1]	$ 38,986	[1]	$ 38,038	[1]	$ 45,739	$ 38,986	$ 38,038	$ 181,193	$ 170,756	$ 160,546
Operating Income	5,321	[1],[2]	7,901	[1]	7,500	[1]	7,233	[1]	6,160	[1]	7,269	[1]	6,466	[1]	6,201	[1]	7,269	6,466	6,201	27,955	26,096	19,970
Net Income	2,704	[1],[2]	3,949	[1]	3,974	[1]	4,348	[1]	5,130	[1]	4,816	[1]	5,248	[1]	4,759	[1]	4,816	5,248	4,759	14,975	19,953	29,847
Net Income attributable to AT&T	$ 2,394	[1],[2]	$ 3,700	[1]	$ 3,713	[1]	$ 4,096	[1]	$ 4,858	[1]	$ 4,718	[1]	$ 5,132	[1]	$ 4,662	[1]	$ 4,718	$ 5,132	$ 4,662	$ 13,903	$ 19,370	$ 29,450
Basic Earnings Per Share Attributable to Common Stock	$ 0.33	[3]	$ 0.50	[3]	$ 0.51	[3]	$ 0.56	[3]	$ 0.66	[3]	$ 0.65	[3]	$ 0.81	[3]	$ 0.75	[3]	$ 0.65	$ 0.81	$ 0.75	$ 1.90	$ 2.85	$ 4.77
Diluted Earnings Per Share Attributable to Common Stock	0.33	[3]	0.50	[3]	0.51	[3]	0.56	[3]	0.66	[3]	0.65	[3]	0.81	[3]	0.75	[3]	$ 0.65	$ 0.81	$ 0.75	1.89	2.85	$ 4.76
Sale of Stock Price Per Share [Line Items]
Stock Price Per Share	39.08		37.84		33.51		31.36		28.54		33.58		32.11		35.65					39.08	28.54
High
Sale of Stock Price Per Share [Line Items]
Stock Price Per Share	39.70		38.75		33.55		31.64		34.30		34.28		36.39		39.29					39.70	34.30
Low
Sale of Stock Price Per Share [Line Items]
Stock Price Per Share	$ 36.40		$ 31.52		$ 30.05		$ 28.30		$ 26.80		$ 30.13		$ 31.17		$ 34.44					$ 36.40	$ 26.80
[1]	Includes actuarial gains and losses on pension and postretirement benefit plans (Note 15).
[2]	Includes an asset abandonment charge (Note 7).
[3]	Quarterly earnings per share impacts may not add to full-year earnings per share impacts due to the difference in weighted-average common shares for the quarters versus the weighted-average common shares for the year.

Valuation And Qualifying Acco_3

Valuation And Qualifying Accounts (Allowance For Doubtful Accounts) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period		$ 907	$ 663	$ 661
Charged to Costs and Expenses	[1]	2,575	1,791	1,642
Charged to Other Accounts	[2]	0	0	0
Acquisitions	[3]	0	179	0
Deductions	[4]	2,247	1,726	1,640
Balance at End of Period		1,235	907	663
Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period		4,588	4,640	2,283
Charged to Costs and Expenses		(18)	(210)	2,376
Charged to Other Accounts	[5]	371	(53)	(19)
Acquisitions	[3]	0	211	0
Deductions	[6]	0	0	0
Balance at End of Period		$ 4,941	$ 4,588	$ 4,640
[1]	(a) Includes amounts previously written off which were credited directly to this account when recovered. Excludes direct charges and credits to expense for nontrade receivables in the consolidated statements of income.
[2]	(b) Includes amounts related to long-distance carrier receivables which were billed by AT&T.
[3]	(c) Acqusition of Time Warner in 2018.
[4]	(d) Amounts written off as uncollectible, or related to divested entities.
[5]	(a) Includes current year reclassifications from other balance sheet accounts.
[6]	(c) Reductions to valuation allowances related to deferred tax assets.

Uncategorized Items - t-2019123

Label	Element	Value
Noncontrolling Interest [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 29,000,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	35,000,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	3,000,000,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(1,527,000,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	316,000,000
Accumulated Other Comprehensive Income Attributable To AT&T, Net Of Tax [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	1,529,000,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(658,000,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 0