AT&T (T) 8-K 21 Jun 21 Other Events Financial data

Document and Entity Information

Document and Entity Information	Jun. 21, 2021
Entity Listings [Line Items]
Document Type	8-K
Document Period End Date	Jun. 21, 2021
Entity File Number	001-08610
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
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Entity Emerging Growth Company	false
Amendment Flag	false
Entity Central Index Key	0000732717
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)
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
Trading Symbol	T PRA
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
Trading Symbol	T PRC
Security Exchange Name	NYSE
AT&T Inc. 2.650% Global Notes due December 17, 2021
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.650% Global Notes due December 17, 2021
Trading Symbol	T 21B
Security Exchange Name	NYSE
AT&T Inc. 1.450% Global Notes due June 1, 2022
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.450% Global Notes due June 1, 2022
Trading Symbol	T 22B
Security Exchange Name	NYSE
AT&T Inc. 2.500% Global Notes due March 15, 2023
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.500% Global Notes due March 15, 2023
Trading Symbol	T 23
Security Exchange Name	NYSE
AT&T Inc. 2.750% Global Notes due May 19, 2023
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.750% Global Notes due May 19, 2023
Trading Symbol	T 23C
Security Exchange Name	NYSE
AT&T Inc. Floating Rate Global Notes due September 5, 2023
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. Floating Rate Global Notes due September 5, 2023
Trading Symbol	T 23D
Security Exchange Name	NYSE
AT&T Inc. 1.050% Global Notes due September 5, 2023
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.050% Global Notes due September 5, 2023
Trading Symbol	T 23E
Security Exchange Name	NYSE
AT&T Inc. 1.300% Global Notes due September 5, 2023
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.300% Global Notes due September 5, 2023
Trading Symbol	T 23A
Security Exchange Name	NYSE
AT&T Inc. 1.950% Global Notes due September 15, 2023
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.950% Global Notes due September 15, 2023
Trading Symbol	T 23F
Security Exchange Name	NYSE
AT&T Inc. 2.400% Global Notes due March 15, 2024
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.400% Global Notes due March 15, 2024
Trading Symbol	T 24A
Security Exchange Name	NYSE
AT&T Inc. 3.500% Global Notes due December 17, 2025
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.500% Global Notes due December 17, 2025
Trading Symbol	T 25
Security Exchange Name	NYSE
AT&T Inc. 0.250% Global Notes due March 4, 2026
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 0.250% Global Notes due March 4, 2026
Trading Symbol	T 26E
Security Exchange Name	NYSE
AT&T Inc. 1.800% Global Notes due September 5, 2026
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.800% Global Notes due September 5, 2026
Trading Symbol	T 26D
Security Exchange Name	NYSE
AT&T Inc. 2.900% Global Notes due December 4, 2026
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.900% Global Notes due December 4, 2026
Trading Symbol	T 26A
Security Exchange Name	NYSE
AT&T Inc. 1.600% Global Notes due May 19, 2028
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.600% Global Notes due May 19, 2028
Trading Symbol	T 28C
Security Exchange Name	NYSE
AT&T Inc. 2.350% Global Notes due September 5, 2029
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.350% Global Notes due September 5, 2029
Trading Symbol	T 29D
Security Exchange Name	NYSE
AT&T Inc. 4.375% Global Notes due September 14, 2029
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.375% Global Notes due September 14, 2029
Trading Symbol	T 29B
Security Exchange Name	NYSE
AT&T Inc. 2.600% Global Notes due December 17, 2029
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.600% Global Notes due December 17, 2029
Trading Symbol	T 29A
Security Exchange Name	NYSE
AT&T Inc. 0.800% Global Notes due March 4, 2030
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 0.800% Global Notes due March 4, 2030
Trading Symbol	T 30B
Security Exchange Name	NYSE
AT&T Inc. 2.050% Global Notes due May 19, 2032
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.050% Global Notes due May 19, 2032
Trading Symbol	T 32A
Security Exchange Name	NYSE
AT&T Inc. 3.550% Global Notes due December 17, 2032
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.550% Global Notes due December 17, 2032
Trading Symbol	T 32
Security Exchange Name	NYSE
AT&T Inc. 5.200% Global Notes due November 18, 2033
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 5.200% Global Notes due November 18, 2033
Trading Symbol	T 33
Security Exchange Name	NYSE
AT&T Inc. 3.375% Global Notes due March 15, 2034
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.375% Global Notes due March 15, 2034
Trading Symbol	T 34
Security Exchange Name	NYSE
AT&T Inc. 2.450% Global Notes due March 15, 2035
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.450% Global Notes due March 15, 2035
Trading Symbol	T 35
Security Exchange Name	NYSE
AT&T Inc. 3.150% Global Notes due September 4, 2036
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.150% Global Notes due September 4, 2036
Trading Symbol	T 36A
Security Exchange Name	NYSE
AT&T Inc. 2.600% Global Notes due May 19, 2038
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 2.600% Global Notes due May 19, 2038
Trading Symbol	T 38C
Security Exchange Name	NYSE
AT&T Inc. 1.800% Global Notes due September 14, 2039
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 1.800% Global Notes due September 14, 2039
Trading Symbol	T 39B
Security Exchange Name	NYSE
AT&T Inc. 7.000% Global Notes due April 30, 2040
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 7.000% Global Notes due April 30, 2040
Trading Symbol	T 40
Security Exchange Name	NYSE
AT&T Inc. 4.250% Global Notes due June 1, 2043
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.250% Global Notes due June 1, 2043
Trading Symbol	T 43
Security Exchange Name	NYSE
AT&T Inc. 4.875% Global Notes due June 1, 2044
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.875% Global Notes due June 1, 2044
Trading Symbol	T 44
Security Exchange Name	NYSE
AT&T Inc. 4.000% Global Notes due June 1, 2049
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.000% Global Notes due June 1, 2049
Trading Symbol	T 49A
Security Exchange Name	NYSE
AT&T Inc. 4.250% Global Notes due March 1, 2050
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 4.250% Global Notes due March 1, 2050
Trading Symbol	T 50
Security Exchange Name	NYSE
AT&T Inc. 3.750% Global Notes due September 1, 2050
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 3.750% Global Notes due September 1, 2050
Trading Symbol	T 50A
Security Exchange Name	NYSE
AT&T Inc. 5.350% Global Notes due November 1, 2066
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 5.350% Global Notes due November 1, 2066
Trading Symbol	TBB
Security Exchange Name	NYSE
AT&T Inc. 5.625% Global Notes due August 1, 2067
Entity Listings [Line Items]
Title of 12(b) Security	AT&T Inc. 5.625% Global Notes due August 1, 2067
Trading Symbol	TBC
Security Exchange Name	NYSE

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues
Total operating revenues	$ 171,760	$ 181,193	$ 170,756
Cost of revenues
Other cost of revenues (exclusive of depreciation and amortization shown separately below)	32,909	34,356	32,906
Selling, general and administrative	38,039	39,422	36,765
Asset impairments and abandonments	18,880	1,458	46
Depreciation and amortization	28,516	28,217	28,430
Total operating expenses	165,355	153,238	144,660
Operating Income (Loss)	6,405	27,955	26,096
Other Income (Expense)
Interest expense	(7,925)	(8,422)	(7,957)
Equity in net income (loss) of affiliates	95	6	(48)
Other income (expense) – net	(1,431)	(1,071)	6,782
Total other income (expense)	(9,261)	(9,487)	(1,223)
Income (Loss) Before Income Taxes	(2,856)	18,468	24,873
Income tax expense	965	3,493	4,920
Net Income (Loss)	(3,821)	14,975	19,953
Less: Net Income Attributable to Noncontrolling Interest	(1,355)	(1,072)	(583)
Net Income (Loss) Attributable to AT&T	(5,176)	13,903	19,370
Less: Preferred Stock Dividends	(193)	(3)	0
Net Income (Loss) Attributable to Common Stock	$ (5,369)	$ 13,900	$ 19,370
Basic Earnings Per Share Attributable to Common Stock (in dollars per share)	$ (0.75)	$ 1.90	$ 2.85
Diluted Earnings Per Share Attributable to Common Stock (in dollars per share)	$ (0.75)	$ 1.89	$ 2.85
Service
Operating Revenues
Total operating revenues	$ 152,767	$ 163,499	$ 152,345
Equipment
Operating Revenues
Total operating revenues	18,993	17,694	18,411
Cost of revenues
Cost of goods and services sold	19,706	18,653	19,786
Broadcast, programming and operations
Cost of revenues
Cost of goods and services sold	$ 27,305	$ 31,132	$ 26,727

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (3,821)	$ 14,975	$ 19,953
Foreign Currency:
Translation adjustment (includes $(59), $(9) and $(32) attributable to noncontrolling interest), net of taxes of $(42), $18 and $(45)	(929)	19	(1,062)
Securities:
Net unrealized gains (losses), net of taxes of $27, $17 and $(1)	78	50	(4)
Reclassification adjustment included in net income, net of taxes of $(5), $0 and $0	(15)	0	0
Derivative Instruments:
Net unrealized gains (losses), net of taxes of $(212), $(240) and $(156)	(811)	(900)
Net unrealized gains (losses), net of taxes of $(212), $(240) and $(156)			(597)
Reclassification adjustment included in net income, net of taxes of $18, $12 and $6	69	45
Reclassification adjustment included in net income, net of taxes of $18, $12 and $6			13
Defined benefit postretirement plans:
Net prior service credit arising during period, net of taxes of $735, $1,134 and $271	2,250	3,457	830
Amortization of net prior service credit included in net income, net of taxes of $(601), $(475) and $(431)	(1,841)	(1,459)	(1,322)
Other comprehensive income (loss)	(1,199)	1,212	(2,142)
Total comprehensive income (loss)	(5,020)	16,187	17,811
Less: Total comprehensive income attributable to noncontrolling interest	(1,296)	(1,063)	(551)
Total Comprehensive Income (Loss) Attributable to AT&T	$ (6,316)	$ 15,124	$ 17,260

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, attributable to noncontrolling interest, net of taxes	$ (59)	$ (9)	$ (32)
Foreign currency translation adjustments - tax effect	(42)	18	(45)
Unrealized gains (losses) on securities - tax effect	27	17	(1)
Reclassification adjustment included in net income on securities - tax effect	(5)	0	0
Unrealized gains (losses) on derivatives - tax effect	(212)	(240)
Unrealized gains (losses) on derivatives - tax effect			(156)
Reclassification adjustment included in net income on derivatives - tax effect	18	12
Reclassification adjustment included in net income on derivatives - tax effect			6
Net prior service credit (cost) arising during period - tax effect	735	1,134	271
Amortization of net prior service credit included in net income - tax effect	$ (601)	$ (475)	$ (431)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 9,740	$ 12,130
Accounts receivable - net of related allowance for credit loss of $1,221 and $1,235	20,215	22,636
Prepaid expenses	1,822	1,631
Other current assets	20,231	18,364
Total current assets	52,008	54,761
Noncurrent Inventories and Theatrical Film and Television Production Costs	14,752	12,434
Property, Plant and Equipment – Net	127,315	130,128
Goodwill	135,259	146,241
Licenses – Net	93,840	97,907
Other Intangible Assets – Net	15,386	20,798
Investments in and Advances to Equity Affiliates	1,780	3,695
Operating Lease Right-Of-Use Assets	24,714	24,039
Other Assets	23,617	22,754
Total Assets	525,761	551,669
Current Liabilities
Debt maturing within one year	3,470	11,838
Accounts payable and accrued liabilities	49,032	45,956
Advanced billings and customer deposits	6,176	6,124
Accrued taxes	1,019	1,212
Dividends payable	3,741	3,781
Total current liabilities	63,438	68,911
Long-Term Debt	153,775	151,309
Deferred Credits and Other Noncurrent Liabilities
Deferred income taxes	60,472	59,502
Postemployment benefit obligation	18,276	18,788
Operating lease liabilities	22,202	21,804
Other noncurrent liabilities	28,358	29,421
Total deferred credits and other noncurrent liabilities	129,308	129,515
Stockholders’ Equity
Common stock ($1 par value, 14,000,000,000 authorized at December 31, 2020 and December 31, 2019: issued 7,620,748,598 at December 31, 2020 and December 31, 2019)	7,621	7,621
Additional paid-in capital	130,175	126,279
Retained earnings	37,457	57,936
Treasury stock (494,826,583 at December 31, 2020 and 366,193,458 at December 31, 2019, at cost)	(17,910)	(13,085)
Accumulated other comprehensive income	4,330	5,470
Noncontrolling interest	17,567	17,713
Total stockholders’ equity	179,240	201,934
Total Liabilities and Stockholders’ Equity	525,761	551,669
Series A (48,000 issued and outstanding at December 31, 2020 and December 31, 2019)
Stockholders’ Equity
Preferred stock ($1 par value, 10,000,000 authorized):	0	0
Series B (20,000 issued and outstanding at December 31, 2020 and 0 issued and outstanding at December 31, 2019)
Stockholders’ Equity
Preferred stock ($1 par value, 10,000,000 authorized):	0	0
Series C (70,000 issued and outstanding at December 31, 2020 and 0 issued and outstanding at December 31, 2019)
Stockholders’ Equity
Preferred stock ($1 par value, 10,000,000 authorized):	0	0
Trademarks And Trade Names - Net
Current Assets
Finite-Lived Intangible Assets - Net	23,297	23,567
Distribution Networks – Net
Current Assets
Finite-Lived Intangible Assets - Net	$ 13,793	$ 15,345

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Allowances for credit losses	$ 1,221	$ 1,235
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	14,000,000,000	14,000,000,000
Common stock, issued (in shares)	7,620,748,598	7,620,748,598
Treasury stock, held (in shares)	494,826,583	366,193,458
Preferred Stock – Series A
Preferred stock, issued (in shares)	48,000	48,000
Preferred stock, outstanding (in shares)	48,000	48,000
Preferred Stock – Series B
Preferred stock, issued (in shares)	20,000	0
Preferred stock, outstanding (in shares)	20,000	0
Preferred Stock – Series C
Preferred stock, issued (in shares)	70,000	0
Preferred stock, outstanding (in shares)	70,000	0

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net income (loss)	$ (3,821)	$ 14,975	$ 19,953
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	28,516	28,217	28,430
Amortization of film and television costs	8,603	9,587	3,772
Undistributed earnings from investments in equity affiliates	38	295	292
Provision for uncollectible accounts	1,972	2,575	1,791
Deferred income tax expense	1,675	1,806	4,931
Net (gain) loss on investments, net of impairments	(742)	(1,218)	(739)
Pension and postretirement benefit expense (credit)	(2,992)	(2,002)	(1,148)
Actuarial (gain) loss on pension and postretirement benefits	4,169	5,171	(3,412)
Asset impairments and abandonments	18,880	1,458	46
Changes in operating assets and liabilities:
Receivables	2,216	2,812	(1,580)
Other current assets, inventories and theatrical film and television production costs	(13,070)	(12,852)	(6,442)
Accounts payable and other accrued liabilities	(1,410)	(1,524)	1,602
Equipment installment receivables and related sales	(1,429)	548	(490)
Deferred customer contract acquisition and fulfillment costs	376	(910)	(3,458)
Postretirement claims and contributions	(985)	(1,008)	(936)
Other - net	1,134	738	990
Total adjustments	46,951	33,693	23,649
Net Cash Provided by Operating Activities	43,130	48,668	43,602
Investing Activities
Capital expenditures, including $(123), $(200) and $(493) of interest during construction	(15,675)	(19,635)	(21,251)
Acquisitions, net of cash acquired	(1,851)	(1,809)	(43,309)
Dispositions	3,641	4,684	2,148
(Purchases), sales and settlement of securities and investments, net	497	435	(183)
Advances to and investments in equity affiliates, net	(160)	(365)	(1,050)
Cash collections of deferred purchase price	0	0	500
Net Cash Used in Investing Activities	(13,548)	(16,690)	(63,145)
Financing Activities
Net change in short-term borrowings with original maturities of three months or less	(17)	(276)	(821)
Issuance of other short-term borrowings	9,440	4,012	4,898
Repayment of other short-term borrowings	(9,467)	(6,904)	(2,098)
Issuance of long-term debt	31,988	17,039	41,875
Repayment of long-term debt	(39,964)	(27,592)	(52,643)
Payment of vendor financing	(2,966)	(3,050)	(560)
Issuance of preferred stock	3,869	1,164	0
Purchase of treasury stock	(5,498)	(2,417)	(609)
Issuance of treasury stock	105	631	745
Issuance of preferred interests in subsidiaries	1,979	7,876	0
Redemption of preferred interest in subsidiary	(1,950)	0	0
Dividends paid	(14,956)	(14,888)	(13,410)
Other - net	(4,570)	(678)	(3,366)
Net Cash Used in Financing Activities	(32,007)	(25,083)	(25,989)
Net (decrease) increase in cash and cash equivalents and restricted cash	(2,425)	6,895	(45,532)
Cash and cash equivalents and restricted cash beginning of year	12,295	5,400	50,932
Cash and Cash Equivalents and Restricted Cash End of Year	$ 9,870	$ 12,295	$ 5,400

Consolidated Statements Of Ca_2

Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Cash Flows [Abstract]
Capital expenditures, interest during construction	$ (123)	$ (200)	$ (493)

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Preferred StockPreferred Stock – Series A	Preferred StockPreferred Stock – Series B	Preferred StockPreferred Stock – Series C	Common Stock	Additional Paid-In Capital	Additional Paid-In CapitalPreferred Stock	Additional Paid-In CapitalCommon Stock	Retained Earnings	Retained EarningsCumulative effect of accounting changes and other adjustments	Retained EarningsAdjusted beginning balance	Treasury Stock	Accumulated Other Comprehensive Income Attributable to AT&T, net of tax	Accumulated Other Comprehensive Income Attributable to AT&T, net of taxCumulative effect of accounting changes and other adjustments	Accumulated Other Comprehensive Income Attributable to AT&T, net of taxAdjusted beginning balance	Noncontrolling Interest	Noncontrolling InterestCumulative effect of accounting changes and other adjustments	Noncontrolling InterestAdjusted beginning balance
Balance at beginning of year at Dec. 31, 2017	$ 142,007	$ 0	$ 0	$ 0	$ 6,495	$ 89,563			$ 50,500	$ 3,000	$ 53,500	$ (12,714)	$ 7,017	$ (658)	$ 6,359	$ 1,146	$ 35	$ 1,181
Balance at beginning of year (in shares) at Dec. 31, 2017		0	0	0	6,495							(356)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase and acquisition of common stock								$ 0
Issuance of stock		$ 0	$ 0	$ 0	$ 1,126		$ 0	35,473
Issuance of stock (in shares)		0	0	0	1,126
Repurchase and acquisition of common stock												$ (692)
Repurchase and acquisition common stock (in shares)												(20)
Issuance of treasury stock						(115)						$ 1,347
Issuance of treasury stock (in shares)												37
Share-based payments						604
Changes related to acquisition of interests held by noncontrolling owners						0
Net income (loss) attributable to AT&T	19,370								19,370
Preferred stock dividends									0
Common stock dividends ($2.08, $2.05, and $2.01 per share)									(14,117)
Other comprehensive income (loss) attributable to AT&T	(2,110)												(2,110)
Net income attributable to noncontrolling interest	583															583
Issuance and acquisition of noncontrolling owners																8,804
Redemption of noncontrolling interest																0
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	$ 0	$ 0	$ 7,621	125,525			58,753	316	59,069	$ (12,059)	4,249	0	4,249	9,795	29	9,824
Balance at end of year (in shares) at Dec. 31, 2018		0	0	0	7,621							(339)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase and acquisition of common stock								0
Issuance of stock		$ 0	$ 0	$ 0	$ 0		1,164	0
Issuance of stock (in shares)		0	0	0	0
Repurchase and acquisition of common stock												$ (2,492)
Repurchase and acquisition common stock (in shares)												(67)
Issuance of treasury stock						(125)						$ 1,466
Issuance of treasury stock (in shares)												40
Share-based payments						(271)
Changes related to acquisition of interests held by noncontrolling owners						(14)
Net income (loss) attributable to AT&T	13,903								13,903
Preferred stock dividends									(8)
Common stock dividends ($2.08, $2.05, and $2.01 per share)									(15,028)
Other comprehensive income (loss) attributable to AT&T	1,221												1,221
Net income attributable to noncontrolling interest	1,072															1,072
Issuance and acquisition of noncontrolling owners																7,881
Redemption of noncontrolling interest																0
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	$ 0	$ 0	$ 7,621	126,279			57,936	$ (293)	$ 57,643	$ (13,085)	5,470	$ 0	$ 5,470	17,713	$ (7)	$ 17,706
Balance at end of year (in shares) at Dec. 31, 2019		0	0	0	7,621							(366)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase and acquisition of common stock								67
Issuance of stock		$ 0	$ 0	$ 0	$ 0		$ 3,869	$ 0
Issuance of stock (in shares)		0	0	0	0
Repurchase and acquisition of common stock	$ (5,278)											$ (5,631)
Repurchase and acquisition common stock (in shares)	(142)											(150)
Issuance of treasury stock						(62)						$ 806
Issuance of treasury stock (in shares)												21
Share-based payments						18
Changes related to acquisition of interests held by noncontrolling owners						4
Net income (loss) attributable to AT&T	$ (5,176)								(5,176)
Preferred stock dividends									(139)
Common stock dividends ($2.08, $2.05, and $2.01 per share)									(14,871)
Other comprehensive income (loss) attributable to AT&T	(1,140)												(1,140)
Net income attributable to noncontrolling interest	1,355															1,355
Issuance and acquisition of noncontrolling owners																1,979
Redemption of noncontrolling interest																(1,950)
Distributions																(1,464)
Acquisition of interests held by noncontrolling owners																0
Translation adjustments attributable to noncontrolling interest, net of taxes	59															(59)
Balance at end of year at Dec. 31, 2020	$ 179,240	$ 0	$ 0	$ 0	$ 7,621	$ 130,175			$ 37,457			$ (17,910)	$ 4,330			$ 17,567
Balance at end of year (in shares) at Dec. 31, 2020		0	0	0	7,621							(495)

Consolidated Statements Of Ch_2

Consolidated Statements Of Changes In Stockholders' Equity (Parenthetical) - $ / shares	1 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends to stockholders (in dollars per share)	$ 0.52	$ 0.52	$ 2.08	$ 2.05	$ 2.01

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	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 subsidiaries and affiliates which we control, 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 subsidiaries and partnerships which we do not control but 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, including potential impacts arising from the COVID-19 pandemic and other estimates of probable losses and expenses, that affect the amounts reported in the financial statements and accompanying notes. 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 and Note 9 for a discussion of the separation of our former Entertainment Group into two reporting units, Video and Consumer Wireline (formerly Broadband). Accounting Policies and Adopted Accounting Standards Credit Losses As of January 1, 2020, we adopted, through modified retrospective application, the Financial Accounting Standards Board’s (FASB) Accounting Standards Update (ASU) No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” or Accounting Standards Codification (ASC) 326 (ASC 326), which replaces the incurred loss impairment methodology under prior GAAP with an expected credit loss model. ASC 326 affects trade receivables, loans, contract assets, certain beneficial interests, off-balance-sheet credit exposures not accounted for as insurance and other financial assets that are not subject to fair value through net income, as defined by the standard. Under the expected credit loss model, we are required to consider future economic trends to estimate expected credit losses over the lifetime of the asset. Upon adoption on January 1, 2020, we recorded a $293 reduction to “Retained earnings,” $395 increase to “Allowances for credit losses” applicable to our trade and loan receivables, $10 reduction of contract assets, $105 reduction of net deferred income tax liability and $7 reduction of “Noncontrolling interest.” Our adoption of ASC 326 did not have a material impact on our financial statements. Leases As of January 1, 2019, we adopted, with modified retrospective application, the FASB's ASU No. 2016-02, “Leases (Topic 842)” (ASC 842), which replaces existing leasing rules with a comprehensive lease measurement and recognition standard and expanded disclosure requirements (see Note 8). ASC 842 requires lessees to recognize most leases on their balance sheets as liabilities, with corresponding “right-of-use” assets. For income statement recognition purposes, leases are classified as either a finance or an operating lease without relying upon bright-line tests. The key change upon adoption of the standard was balance sheet recognition of operating leases, 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 but recorded a cumulative effect adjustment to retained earnings on January 1, 2019. We elected the package of practical expedients permitted under the transition guidance within the new standard, which, among other things, allowed us to carry forward our historical lease classification. We also elected the practical expedient related to land easements, allowing us to carry forward our accounting treatment for land easements on existing agreements that were not accounted for as leases. We excluded leases with original terms of one year or less. Additionally, we elected to not separate lease and non-lease components for certain classes of assets. Our accounting for finance leases did not change from our prior accounting for capital leases. The adoption of ASC 842 resulted in the recognition of an operating lease liability of $22,121 and an operating right-of-use asset of the same amount. Existing prepaid and deferred rent accruals were recorded as an offset to the right-of-use asset, resulting in a net asset of $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, and had no impact on our debt-covenant compliance under our current agreements. 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 as of January 1, 2019, with prospective application. The standard eliminates certain revenue-related constraints on capitalization of inventory costs for episodic television that existed under prior guidance. In addition, the balance sheet classification requirements that existed in prior guidance for film production costs and programming inventory were eliminated. As of January 1, 2019, we reclassified $2,274 of our programming inventory costs from “Other current assets” to “Other Assets” in accordance with the guidance (see Note 11). This change in accounting did 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 method, which does not allow us to adjust prior periods. We applied the rules to all open contracts existing as of January 1, 2018, recording an increase of $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 prospective ly record changes in the fair value of our equity investments, except for those accounted for under the equity method, in net income instead of in accumulated other comprehensive income (accumulated OCI). As of January 1, 2018, we recorded an increase of $658 in retained earnings for the cumulative effect of the adoption of ASU 2016-01, with an offset to accumulated OCI. 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), which was enacted on December 22, 2017, 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. 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, as allowed by the Securities and Exchange Commission (SEC) in Staff Accounting Bulletin (SAB) 118. (See Note 14) 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, 2020, we held $2,842 in cash and $6,898 in money market funds and other cash equivalents. Of our total cash and cash equivalents, $2,205 resided in foreign jurisdictions, some of which is subject to restrictions on repatriation. Allowance for Credit Losses We record expense to maintain an allowance for credit losses 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 allowances for trade receivables and loans, we consider the probability of recoverability of accounts receivable based on past experience, taking into account current collection trends and general economic factors, including bankruptcy rates. We also consider future economic trends to estimate expected credit losses over the lifetime of the asset. 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 $3,592 at December 31, 2020 and $2,864 at December 31, 2019. 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 are determined using the film forecast computation method. Under this method, the amortization of capitalized costs and the accrual of participations and residuals are 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. (See Note 11) 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 generally does not 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 an impairment of long-lived assets of the video business and other network 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 - Net” 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 to seven-year period, reflecting the estimated period during which these assets will remain in service. 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 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. During the first quarter of 2020, in conjunction with the nationwide launch of AT&T TV and our customers’ continued shift from linear to streaming video services, we reassessed the estimated economic lives and renewal assumptions for our orbital slot licenses. As a result, we have changed the estimated lives of our orbital slot licenses from indefinite to finite-lived, effective January 1, 2020, and began amortizing these licenses using the sum-of-months-digits method over their average remaining economic life of 15 years at January 1, 2020. This change in accounting increased amortization expense $1,504, or $0.16 per diluted share available to common stock for 2020. 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. During the first quarter of 2020, we reassessed and changed the estimated economic lives of certain trade names in our Latin America business from indefinite to finite-lived and began amortizing them using the straight-line method over their average remaining economic life of 15 years. This change had an insignificant impact on our financial statements. 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. Prior to 2020, orbital slots were 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). As of January 1, 2020, on a prospective basis, orbital slots are amortized using the sum-of-the-months-digits method of amortization over their average remaining economic life. 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. These assets, along with other long-lived assets, are reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. Advertising Costs We expense advertising costs for products and services or for promoting our corporate image as incurred (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 use 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 benefits, 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 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 do not expect ASU 2019-12 to have a material impact on our financial statements. Reference Rate Reform In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting” (ASU 2020-04, as amended), which provides optional expedients, and allows for certain exceptions to existing GAAP, for contract modifications triggered by the expected market transition of certain benchmark interest rates to alternative reference rates. ASU 2020-04 applies to contracts, hedging relationships, certain derivatives and other arrangements that reference the London Interbank Offering Rate (LIBOR) or any other rates ending after December 31, 2022. ASU 2020-04 became effective immediately. We are evaluating the impact of our adoption of ASU 2020-04, including optional expedients, to our financial statements. Convertible Instruments In August 2020, the FASB issued ASU No. 2020-06, “Debt—Debt With Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity” (ASU 2020-06), which eliminated certain separation models regarding cash conversion and beneficial conversion features to simplify reporting for convertible instruments as a single liability or equity, with no separate accounting for embedded conversion features. ASU 2020-06 will be effective for fiscal years beginning after December 31, 2021, under modified retrospective or full retrospective application, subject to early adoption in 2021. We are evaluating the impact of our adoption of ASU 2020-06 on our financial statements.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	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, 2020 2019 2018 Numerators Numerator for basic earnings per share: Net Income (Loss) $ (3,821) $ 14,975 $ 19,953 Less: Net Income Attributable to Noncontrolling Interest (1,355) (1,072) (583) Net Income (Loss) Attributable to AT&T (5,176) 13,903 19,370 Less: Preferred Stock Dividends (193) (3) — Net Income (Loss) Attributable to Common Stock (5,369) 13,900 19,370 Dilutive potential common shares: Share-based payment 1 23 21 19 Numerator for diluted earnings per share $ (5,346) $ 13,921 $ 19,389 Denominators (000,000) Denominator for basic earnings per share: Weighted average number of common shares outstanding 7,157 7,319 6,778 Dilutive potential common shares: Share-based payment (in shares) 1 26 29 28 Denominator for diluted earnings per share 7,183 7,348 6,806 Basic Earnings Per Share Attributable to Common Stock $ (0.75) $ 1.90 $ 2.85 Diluted Earnings Per Share Attributable to Common Stock 1 $ (0.75) $ 1.89 $ 2.85 1 For 2020, dilutive potential common shares are not included in the computation of diluted earnings per share because their effect is antidilutive as a result of the net loss. In the first quarter of 2020, we completed 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, we paid the financial institution $4,000 and received 104.8 million shares.

Other Comprehensive Income

Other Comprehensive Income	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income	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 Net Unrealized Net Unrealized Defined Benefit Accumulated Other 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 4 — (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 Other comprehensive income (loss) before reclassifications (870) 78 (811) 2,250 647 Amounts reclassified from accumulated OCI — 1 (15) 1 69 2 (1,841) 3 (1,787) Net other comprehensive income (loss) (870) 63 (742) 409 (1,140) Balance as of December 31, 2020 $ (3,926) $ 111 $ (779) $ 8,924 $ 4,330 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) – net” in the consolidated statements of income (see Note 15). 4 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, 2020
Segment Reporting [Abstract]
Segment Information	NOTE 4. SEGMENT INFORMATION Our segments are comprised of 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 three reportable segments: (1) Communications, (2) WarnerMedia and (3) Latin America. We have recast our segment results for all prior periods to reflect the following: Communications segment results have been recast to remove the Video and Government Solutions businesses that were classified as held-for sale beginning in the first quarter of 2021, instead reporting those results in Corporate and Other, consistent with our historical practice. Additionally, we refined the allocation of shared infrastructure and deferred customer acquisition costs between Consumer Wireline and Video. WarnerMedia segment results were recast to include our prior Xandr segment within our WarnerMedia segment and to remove the Crunchyroll anime business that is classified as held-for-sale and removed from the WarnerMedia segment, instead including it in Corporate and Other. 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 depreciation and amortization expenses incurred in operating contribution nor is it burdened by 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. The Communications segment provides wireless and wireline telecom and broadband services to consumers located in the U.S. and businesses globally. Our business strategies reflect bundled product offerings that cut across product lines and utilize shared assets. In December 2020, we changed our management strategy and reevaluated our domestic video business, allowing us to maximize value in our domestic video business and further accelerate our ability to innovate and execute in our fast-growing broadband and fiber business. In conjunction with the strategy change, we separated the former Entertainment Group into two business units, Video and Consumer Wireline, and recast our results for all prior periods. The Business Wireline business unit was also recast to remove video operations, instead including those in Video. Beginning in the first quarter of 2021, the Video business was classified as held-for-sale and recast to be reported in Corporate and Other. This segment contains the following business units: • Mobility provides nationwide wireless service and equipment. • Business Wireline provides advanced IP-based services, as well as traditional voice and data services to business customers. • Consumer Wireline provides internet, including broadband fiber, and legacy telephony voice communication services to residential customers. The WarnerMedia segment develops, produces and distributes feature films, television, gaming and other content in various physical and digital formats globally. Historical financial results of Eliminations & Other included in the WarnerMedia segment have been recast to include Xandr, previously a separate reportable segment, and to remove the Crunchyroll anime business that was classified as held-for-sale. This segment contains the following: • 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 HBO Max domestically and premium pay, basic tier television internationally, and content licensing and home entertainment. • Warner Bros. primarily 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. • Eliminations & Other includes the Xandr advertising business, and also removes transactions between the Turner, Home Box Office and Warner Bros. business units, including internal sales of content to the HBO Max platform that began in the fourth quarter of 2019 (see Note 5). The Latin America segment provides entertainment and wireless services outside of the U.S. This segment contains the following business units: • Vrio provides video services primarily to residential customers using satellite technology in Latin America and the Caribbean. • Mexico provides wireless service and equipment to customers in Mexico. 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, and (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.” • Video , which provides video, including over-the-top (OTT) services, and also sells multiplatform advertising services as video revenues. • Acquisition-related items, which consists of items associated with the merger and integration of acquired businesses, including amortization of intangible assets. • Certain significant items, which includes (1) employee separation charges associated with voluntary and/or strategic offers, (2) asset impairments and abandonments, 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 channel distribution 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, 2020 Revenues Operations EBITDA Depreciation and Amortization Operating Equity in Net Segment Communications Mobility $ 72,564 $ 42,106 $ 30,458 $ 8,086 $ 22,372 $ — $ 22,372 Business Wireline 25,083 15,303 9,780 5,216 4,564 — 4,564 Consumer Wireline 12,318 8,027 4,291 2,914 1,377 — 1,377 Total Communications 109,965 65,436 44,529 16,216 28,313 — 28,313 WarnerMedia Turner 12,568 6,954 5,614 277 5,337 (2) 5,335 Home Box Office 6,808 6,028 780 98 682 16 698 Warner Bros. 12,154 9,917 2,237 169 2,068 (70) 1,998 Eliminations and other (1,088) (1,320) 232 127 105 74 179 Total WarnerMedia 30,442 21,579 8,863 671 8,192 18 8,210 Latin America Vrio 3,154 2,800 354 520 (166) 24 (142) Mexico 2,562 2,636 (74) 513 (587) — (587) Total Latin America 5,716 5,436 280 1,033 (753) 24 (729) Segment Total 146,123 92,451 53,672 17,920 35,752 $ 42 $ 35,794 Corporate and Other Corporate 1 2,207 4,205 (1,998) 310 (2,308) Video 28,610 24,174 4,436 2,262 2,174 Acquisition-related items — 468 (468) 8,012 (8,480) Certain significant items — 19,156 (19,156) 14 (19,170) Eliminations and consolidations (5,180) (3,615) (1,565) (2) (1,563) AT&T Inc. $ 171,760 $ 136,839 $ 34,921 $ 28,516 $ 6,405 1 Operations and Support Expenses include $2,442 for the reclassification of prior service credit amortization. For the year ended December 31, 2019 Revenues Operations EBITDA Depreciation Operating Equity in Net Segment Communications Mobility $ 71,056 $ 40,681 $ 30,375 $ 8,054 $ 22,321 $ — $ 22,321 Business Wireline 25,901 15,839 10,062 4,925 5,137 — 5,137 Consumer Wireline 13,012 7,775 5,237 2,880 2,357 — 2,357 Total Communications 109,969 64,295 45,674 15,859 29,815 — 29,815 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 Eliminations and other 1,030 304 726 90 636 109 745 Total WarnerMedia 35,259 24,172 11,087 589 10,498 161 10,659 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) Segment Total 152,191 94,930 57,261 17,610 39,651 $ 188 $ 39,839 Corporate and Other Corporate 1 2,203 3,509 (1,306) 645 (1,951) Video 32,124 27,275 4,849 2,461 2,388 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 1 Operations and Support Expenses include $1,934 for the reclassification of prior service credit amortization. For the year ended December 31, 2018 Revenues Operations EBITDA Depreciation Operating Equity in Net Segment Communications Mobility $ 70,521 $ 40,690 $ 29,831 $ 8,263 $ 21,568 $ — $ 21,568 Business Wireline 26,494 16,012 10,482 4,704 5,778 — 5,778 Consumer Wireline 13,108 7,596 5,512 2,623 2,889 — 2,889 Total Communications 110,123 64,298 45,825 15,590 30,235 — 30,235 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 Eliminations and other 1,305 168 1,137 28 1,109 (30) 1,079 Total WarnerMedia 20,585 13,279 7,306 311 6,995 25 7,020 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) Segment Total 138,360 84,735 53,625 17,139 36,486 $ 59 $ 36,545 Corporate and Other Corporate 1 2,481 2,502 (21) 1,637 (1,658) Video 33,363 28,856 4,507 2,698 1,809 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 1 Operations and Support Expenses include $1,753 for the reclassification of prior service credit amortization. The following table is a reconciliation of operating income (loss) to “Income Before Income Taxes” reported in our consolidated statements of income: 2020 2019 2018 Communications $ 28,313 $ 29,815 $ 30,235 WarnerMedia 8,210 10,659 7,020 Latin America (729) (635) (710) Segment Contribution 35,794 39,839 36,545 Reconciling Items: Corporate and Other (2,308) (1,951) (1,658) Video 2,174 2,388 1,809 Merger and integration items (468) (1,032) (1,234) Amortization of intangibles acquired (8,012) (7,460) (6,931) Impairments and abandonments (18,880) (1,458) (46) Gain on spectrum transaction 1 900 — — Employee separation charges and benefit-related (gain) loss (1,177) (624) (587) Other noncash charges (credits), net (13) (43) (111) Natural disaster items — — (181) Segment equity in net income of affiliates (42) (188) (59) Eliminations and consolidations (1,563) (1,516) (1,451) AT&T Operating Income 6,405 27,955 26,096 Interest Expense 7,925 8,422 7,957 Equity in net income (loss) of affiliates 95 6 (48) Other income (expense) - net (1,431) (1,071) 6,782 Income (Loss) Before Income Taxes $ (2,856) $ 18,468 $ 24,873 1 Included as a reduction of “Selling, general and administrative expenses” in the consolidated statements of income. The following table sets forth revenues earned from customers, and property, plant and equipment located in different geographic areas: 2020 2019 2018 Revenues Net Property, Plant & Equipment Revenues Net Property, Plant & Equipment Revenues Net Property, United States $ 155,899 $ 121,208 $ 161,689 $ 122,567 $ 154,795 $ 123,457 Europe 5,387 1,152 6,536 1,854 4,073 1,634 Mexico 2,862 3,530 3,198 3,648 3,100 3,467 Brazil 1,807 694 2,797 1,057 2,724 1,213 All other Latin America 2,679 485 3,219 544 3,055 1,217 Asia/Pacific Rim 2,322 203 2,793 390 2,214 408 Other 804 43 961 68 795 77 Total $ 171,760 $ 127,315 $ 181,193 $ 130,128 $ 170,756 $ 131,473 The following tables present intersegment revenues, assets, investments in equity affiliates and capital expenditures by segment: Intersegment Reconciliation 2020 2019 2018 Intersegment revenues Communications $ 11 $ 26 $ 13 WarnerMedia 3,183 3,318 1,875 Latin America — — — Total Intersegment Revenues 3,194 3,344 1,888 Consolidations 1,986 1,909 1,511 Eliminations and consolidations $ 5,180 $ 5,253 $ 3,399 At or for the years ended December 31, 2020 2019 Assets Investments in Capital Assets Investments in Capital Communications 1 $ 506,102 $ — $ 14,107 $ 492,649 $ — $ 17,410 WarnerMedia 148,037 1,123 699 140,376 3,011 1,205 Latin America 15,811 590 708 20,606 650 757 Corporate and eliminations 1 (144,189) 67 161 (101,962) 34 263 Total $ 525,761 $ 1,780 $ 15,675 $ 551,669 $ 3,695 $ 19,635 1 Amounts above have been updated to reflect the classification of our Video business as held-for-sale (beginning in the first quarter of 2021), which included the recast of historical results to remove Video from our Communications segment and instead report in Corporate and Other.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	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. No customer accounted for more than 10% of consolidated revenues in 2020, 2019 or 2018. 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, facilitates 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 separate performance obligation (e.g., equipment associated with certain video services), we allocate the total transaction price to the related service. When equipment is a separate 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 relationship 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. Intercompany transactions between segments and the dual reporting of certain advertising revenues are included in “Eliminations and consolidations.” Intercompany transactions between Turner, Home Box Office and Warner Bros., including internal sales to HBO Max that began in the fourth quarter of 2019, are included in “Eliminations and Other.” For the year ended December 31, 2020 Service Revenues Wireless Business Advanced Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 55,251 $ — $ — $ — $ — $ — $ 291 $ — $ 17,022 $ 72,564 Business Wireline — 24,313 — — — — — — 770 25,083 Consumer Wireline — — 8,534 2,213 — — — 1,564 7 12,318 WarnerMedia Turner — — — — 7,613 759 3,941 255 — 12,568 Home Box Office — — — — 6,090 692 — 26 — 6,808 Warner Bros. — — — — 50 11,632 6 466 — 12,154 Eliminations and Other 1 — — — — 12 (3,264) 2,178 (14) — (1,088) Latin America Vrio — — — — 3,154 — — — — 3,154 Mexico 1,656 — — — — — — — 906 2,562 Corporate and Other 528 321 — 554 26,747 — 1,718 661 288 30,817 Eliminations and consolidations 2 — — — — (3,110) — (1,718) (352) — (5,180) Total Operating Revenues $ 57,435 $ 24,634 $ 8,534 $ 2,767 $ 40,556 $ 9,819 $ 6,416 $ 2,606 $ 18,993 $ 171,760 1 Eliminations and other of $3,264 include Warner Bros. content sales of approximately $2,250 with HBO Max, $600 with HBO linear and $300 with Turner. 2 Eliminations and consolidations of $3,110 include approximately $1,500 and $950 of Turner and HBO linear channel distribution arrangements with the Video business, respectively. HBO customer subscriptions were approximately $290 with Mobility and $180 with Consumer Wireline. For the year ended December 31, 2019 Service Revenues Wireless Business Advanced Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 55,039 $ — $ — $ — $ — $ — $ 292 $ — $ 15,725 $ 71,056 Business Wireline — 25,116 — — — — — — 785 25,901 Consumer Wireline — — 8,403 2,573 — — — 2,029 7 13,012 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 1 — — — — 13 (1,058) 2,071 4 — 1,030 Latin America Vrio — — — — 4,094 — — — — 4,094 Mexico 1,863 — — — — — — — 1,006 2,869 Corporate and Other 628 325 — 565 30,451 — 1,672 443 171 34,255 Eliminations and consolidations 2 — — — — (3,249) — (1,672) (332) — (5,253) Total Operating Revenues $ 57,530 $ 25,441 $ 8,403 $ 3,138 $ 44,947 $ 13,880 $ 6,970 $ 3,190 $ 17,694 $ 181,193 1 Eliminations and other of $1,058 include Warner Bros. content sales of approximately $500 with HBO linear and $350 with Turner. 2 Eliminations and consolidations of $3,249 include approximately $1,740 and $1,320 of Turner and HBO linear channel distribution arrangements with the Video business, respectively. For the year ended December 31, 2018 Service Revenues Wireless Business Advanced Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 54,063 $ — $ — $ — $ — $ — $ 232 $ — $ 16,226 $ 70,521 Business Wireline — 25,671 — — — — — — 823 26,494 Consumer Wireline — — 7,956 3,042 — — — 2,101 9 13,108 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 1 — — — — 6 (518) 1,807 10 — 1,305 Latin America Vrio — — — — 4,784 — — — — 4,784 Mexico 1,701 — — — — — — — 1,167 2,868 Corporate and Other 718 395 — 288 31,768 — 1,595 845 186 35,795 Eliminations and consolidations 2 — — — — (1,843) — (1,595) 39 — (3,399) Total Operating Revenues $ 56,482 $ 26,066 $ 7,956 $ 3,330 $ 42,170 $ 8,384 $ 4,422 $ 3,535 $ 18,411 $ 170,756 1 Eliminations and other of $518 include Warner Bros. content sales of approximately $225 with HBO linear and $225 with Turner. 2 Eliminations and consolidations of $1,843 include approximately $1,000 and $700 of Turner and HBO linear channel distribution arrangements with the Video business, respectively. 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 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 2020 2019 Deferred Acquisition Costs Other current assets $ 3,087 $ 2,462 Other Assets 3,198 2,991 Total deferred customer contract acquisition costs $ 6,285 $ 5,453 Deferred Fulfillment Costs Other current assets $ 4,118 $ 4,519 Other Assets 5,634 6,439 Total deferred customer contract fulfillment costs $ 9,752 $ 10,958 The following table presents amortization of deferred customer contract acquisition and fulfillment costs, which are recorded in other cost of revenues in our consolidated statements of income, for the year ended December 31: Consolidated Statements of Income 2020 2019 Deferred acquisition cost amortization $ 2,755 $ 2,174 Deferred fulfillment cost amortization 5,110 4,947 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 equipment 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 2020 2019 Contract assets $ 3,501 $ 2,472 Contract liabilities 6,879 6,999 Our beginning of period contract liabilities recorded as customer contract revenue during 2020 was $5,579. Our consolidated balance sheets at December 31, 2020 and 2019 included approximately $2,054 and $1,611, respectively, for the current portion of our contract assets in “Other current assets” and $6,071 and $5,939, 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, 2020, the aggregate amount of the transaction price allocated to remaining performance obligations was $42,072, of which we expect to recognize approximately 60% by the end of 2021, with the remaining balance recognized thereafter.

Acquisitions, Dispositions And

Acquisitions, Dispositions And Other Adjustments	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions, Dispositions And Other Adjustments	NOTE 6. ACQUISITIONS, DISPOSITIONS AND OTHER ADJUSTMENTS Acquisitions HBO Latin America Group (HBO LAG) In May 2020, we acquired the remaining interest in HBO LAG for $141, net of cash acquired. 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 $68. We consolidated that business upon close and recorded those assets at fair value, including $640 of trade names, $271 of distribution networks and $346 of goodwill that is reported in the WarnerMedia segment. These estimates are preliminary in nature and subject to adjustments, which will be finalized within one year from the date of acquisition. Time Warner In June 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. For accounting purposes, the transaction was valued at $79,358. Our consolidated balance sheets include the assets and liabilities of Time Warner, which were measured at fair value. 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) 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 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 WarnerMedia segment. Our investment allows us to create a marketplace for TV and digital video advertising. Spectrum Auctions In June 2020, we completed the acquisition of $2,379 of 37/39 GHz spectrum in a Federal Communications Commission (FCC) auction. Prior to the auction, we exchanged the 39 GHz licenses with a book value of approximately $300 that were previously acquired through FiberTower Corporation for vouchers to be applied against the winning bids and recorded a $900 gain in the first quarter of 2020. These vouchers yielded a value of approximately $1,200, which was applied toward our gross bids. In the second quarter of 2020, we made the final cash payment of $949, bringing the total cash payment to $1,186. In December 2019, we acquired $982 of 24 GHz spectrum in an FCC auction. Dispositions Central European Media Enterprises Ltd. (CME) On October 13, 2020, we completed the sale of our 65.3% interest in CME, a European broadcasting company, for approximately $1,100 and recorded a pre-tax gain of $39. Upon close, we received relief from a debt guarantee originally covering approximately $1,100 that was reduced to $600 at the time of the sale. Operations in Puerto Rico On October 31, 2020, we completed the sale of our previously held-for-sale wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands for approximately $1,950 and recorded a pre-tax loss of $82. Upon sale we removed held-for-sale assets (“Other current assets”) and held-for-sale liabilities (“Accounts payable and accrued liabilities”) that primarily consisted of FCC licenses (approximately $1,100), allocated goodwill (approximately $250), net property, plant and equipment (approximately $850) and net tax liabilities (approximately $500), previously reported on our consolidated balance sheets. The proceeds were used to redeem $1,950 of cumulative preferred interests in a subsidiary that held notes secured by the proceeds of this sale. Hudson Yards In June 2019, we sold our ownership in Hudson Yards North Tower Holdings LLC under a sale-leaseback arrangement for cash proceeds of $2,081 and recorded a loss of approximately $100 resulting from transaction costs (primarily real estate transfer taxes). Hulu In April 2019, we sold our ownership in Hulu for cash proceeds of $1,430 and recorded a pre-tax 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.

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant And Equipment	NOTE 7. PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment is summarized as follows at December 31: Lives (years) 2020 2019 Land - $ 2,571 $ 2,651 Buildings and improvements 2-44 39,418 38,924 Central office equipment 1 3-10 95,981 96,061 Cable, wiring and conduit 15-50 75,409 72,042 Satellites 14-17 908 2,489 Other equipment 3-20 90,883 94,951 Software 3-7 18,482 22,244 Under construction - 4,099 4,176 327,751 333,538 Accumulated depreciation and amortization 200,436 203,410 Property, plant and equipment - net $ 127,315 $ 130,128 1 Includes certain network software. Our depreciation expense was $20,277 in 2020, $20,285 in 2019 and $20,083 in 2018. Depreciation expense included amortization of software totaling $3,483 in 2020, $3,313 in 2019 and $3,092 in 2018. In December 2020, we reassessed our grouping of long-lived assets and identified certain impairment indicators, requiring us to evaluate the recoverability of the long-lived assets of our video business. Based on this evaluation, we determined that these assets were not fully recoverable and recognized pre-tax impairment charges totaling $7,255, of which $1,681 relates to property, plant and equipment, including satellites. The reduced carrying amounts of the impaired assets became their new cost basis. In 2019, we recorded a noncash pre-tax charge of $1,290 to abandon copper assets that we no longer expect will be utilized to support future network activity. The abandonment was considered outside the ordinary course of business.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	NOTE 8. LEASES We have operating and finance leases for certain facilities and equipment used in our operations. Our leases generally have remaining lease terms of up to 15 years. Some of our real estate operating leases contain renewal options that may be exercised, and some of our leases include options to terminate the leases within one year. We have recognized a right-of-use asset for both operating and finance leases, and a corresponding lease liability that represents the present value of our obligation to make payments over the lease term. The present value of the lease payments is calculated using the incremental borrowing rate for operating and finance leases, which was 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 will be updated on a quarterly basis for measurement of new lease liabilities. The components of lease expense were as follows: 2020 2019 Operating lease cost $ 5,896 $ 5,684 Finance lease cost: Amortization of right-of-use assets $ 287 $ 271 Interest on lease obligation 156 169 Total finance lease cost $ 443 $ 440 The following table provides supplemental cash flows information related to leases: 2020 2019 Cash Flows from Operating Activities Cash paid for amounts included in lease obligations: Operating cash flows from operating leases $ 4,852 $ 4,583 Supplemental Lease Cash Flow Disclosures Operating lease right-of-use assets obtained in exchange for new operating lease obligations $ 5,270 $ 7,818 The following tables set forth supplemental balance sheet information related to leases at December 31: 2020 2019 Operating Leases Operating lease right-of-use assets $ 24,714 $ 24,039 Accounts payable and accrued liabilities $ 3,537 3,451 Operating lease obligation 22,202 21,804 Total operating lease obligation $ 25,739 $ 25,255 Finance Leases Property, plant and equipment, at cost $ 3,586 $ 3,534 Accumulated depreciation and amortization (1,361) (1,296) Property, plant and equipment, net $ 2,225 $ 2,238 Current portion of long-term debt $ 189 $ 162 Long-term debt 1,847 1,872 Total finance lease obligation $ 2,036 $ 2,034 2020 2019 Weighted-Average Remaining Lease Term (years) Operating leases 8.5 8.4 Finance leases 9.9 10.3 Weighted-Average Discount Rate Operating leases 4.1 % 4.2 % Finance leases 8.1 % 8.4 % The following table provides the expected future minimum maturities of lease obligations: Operating Leases Finance 2021 $ 4,808 $ 350 2022 4,527 333 2023 4,094 300 2024 3,560 276 2025 2,904 272 Thereafter 11,230 1,609 Total lease payments 31,123 3,140 Less: imputed interest (5,384) (1,104) Total $ 25,739 $ 2,036
Leases	NOTE 8. LEASES We have operating and finance leases for certain facilities and equipment used in our operations. Our leases generally have remaining lease terms of up to 15 years. Some of our real estate operating leases contain renewal options that may be exercised, and some of our leases include options to terminate the leases within one year. We have recognized a right-of-use asset for both operating and finance leases, and a corresponding lease liability that represents the present value of our obligation to make payments over the lease term. The present value of the lease payments is calculated using the incremental borrowing rate for operating and finance leases, which was 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 will be updated on a quarterly basis for measurement of new lease liabilities. The components of lease expense were as follows: 2020 2019 Operating lease cost $ 5,896 $ 5,684 Finance lease cost: Amortization of right-of-use assets $ 287 $ 271 Interest on lease obligation 156 169 Total finance lease cost $ 443 $ 440 The following table provides supplemental cash flows information related to leases: 2020 2019 Cash Flows from Operating Activities Cash paid for amounts included in lease obligations: Operating cash flows from operating leases $ 4,852 $ 4,583 Supplemental Lease Cash Flow Disclosures Operating lease right-of-use assets obtained in exchange for new operating lease obligations $ 5,270 $ 7,818 The following tables set forth supplemental balance sheet information related to leases at December 31: 2020 2019 Operating Leases Operating lease right-of-use assets $ 24,714 $ 24,039 Accounts payable and accrued liabilities $ 3,537 3,451 Operating lease obligation 22,202 21,804 Total operating lease obligation $ 25,739 $ 25,255 Finance Leases Property, plant and equipment, at cost $ 3,586 $ 3,534 Accumulated depreciation and amortization (1,361) (1,296) Property, plant and equipment, net $ 2,225 $ 2,238 Current portion of long-term debt $ 189 $ 162 Long-term debt 1,847 1,872 Total finance lease obligation $ 2,036 $ 2,034 2020 2019 Weighted-Average Remaining Lease Term (years) Operating leases 8.5 8.4 Finance leases 9.9 10.3 Weighted-Average Discount Rate Operating leases 4.1 % 4.2 % Finance leases 8.1 % 8.4 % The following table provides the expected future minimum maturities of lease obligations: Operating Leases Finance 2021 $ 4,808 $ 350 2022 4,527 333 2023 4,094 300 2024 3,560 276 2025 2,904 272 Thereafter 11,230 1,609 Total lease payments 31,123 3,140 Less: imputed interest (5,384) (1,104) Total $ 25,739 $ 2,036

Goodwill And Other Intangible A

Goodwill And Other Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill And Other Intangible Assets	NOTE 9. GOODWILL AND OTHER INTANGIBLE ASSETS We test goodwill for impairment at a reporting unit level, which is deemed to be our principal operating segments or one level below. With our annual impairment testing as of October 1, 2020, the calculated fair values of the reporting units exceeded their book values in all circumstances; however, the Turner, HBO and Entertainment Group (prior to the reporting unit change) fair values exceeded their book values by less than 10%, with COVID-19 impacts, industry trends and our content distribution strategy affecting fair value. In December 2020, we changed our management strategy and reevaluated our domestic video business, allowing us to maximize value in our domestic video business and further accelerate our ability to innovate and execute in our fast-growing broadband and fiber business. The strategy change required us to reassess the grouping and recoverability of the video business long-lived assets. In conjunction with the strategy change, we separated the former Entertainment Group reporting unit into two reporting units, Video and Consumer Wireline, which includes legacy telephony operations. Our recoverability assessment resulted in $7,255 of long-lived asset impairment in the video business, including $4,373 for orbital slots and $1,201 for customer lists. The change in reporting unit required the historical Entertainment Group goodwill to be assigned to the separate Video and Consumer Wireline reporting units, for which we used the relative fair value allocation methodology. The affected reporting units were then tested for goodwill impairment. We recorded an impairment of the entire $8,253 of goodwill allocated to the Video reporting unit. No goodwill impairment was required in the Consumer Wireline reporting unit. As further discussed in Note 23, beginning in the first quarter of 2021, the Video business met the criteria to be classified as held-for-sale and, as a result, was subsequently removed from the former Entertainment Group reporting unit. This change was made subsequent to the recoverability assessment described herein and had no effect on that assessment. In the second quarter of 2020, driven by significant and adverse economic and political environments in Latin America, including the impact of COVID-19, we experienced accelerated subscriber losses and revenue decline in the region, as well as closure of our operations in Venezuela. When combining these business trends and higher weighted-average cost of capital resulting from the increase in country-risk premiums in the region, we concluded that it was more likely than not that the fair value of the Vrio reporting unit, estimated using discounted cash flow and market multiple approaches, was less than its carrying amount. We recorded a $2,212 goodwill impairment in the Vrio reporting unit, with $105 attributable to noncontrolling interest. Other changes to our goodwill in 2020 resulted from foreign currency translation, the held-for-sale treatment of our Crunchyroll anime business and our acquisition of the remaining interest in HBO LAG (see Note 6). In 2020, the prior Xandr segment was combined with our WarnerMedia segment. 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. At December 31, 2020, our Communications segment has four reporting units: Mobility, Video, Consumer Wireline and Business Wireline. Our WarnerMedia segment has four reporting units: Turner, Home Box Office, Warner Bros. and Xandr. Our Latin America segment has two reporting units: Vrio and Mexico. The following table sets forth the changes in the carrying amounts of goodwill by operating segment: 2020 2019 Balance at Acquisitions Impairments Dispositions, Balance at Balance at Acquisitions Dispositions, Balance at Communications $ 100,234 $ — $ (8,253) $ (5) $ 91,976 $ 100,551 $ — $ (317) $ 100,234 WarnerMedia 42,345 415 — (313) 42,447 42,101 66 178 42,345 Latin America 3,662 — (2,212) (614) 836 3,718 — (56) 3,662 Total $ 146,241 $ 415 $ (10,465) $ (932) $ 135,259 $ 146,370 $ 66 $ (195) $ 146,241 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, including the video business previously discussed. In 2020, we changed the estimated lives of our orbital slot licenses from indefinite to finite-lived and began amortizing them over their average remaining economic life of 15 years (see Note 1). Our other intangible assets at December 31 are summarized as follows: 2020 2019 Other Intangible Assets Weighted-Average Life Gross Carrying Accumulated Currency Gross Carrying Accumulated Currency Amortized intangible assets: Wireless licenses 1 24.6 years $ 2,979 $ 271 $ (421) $ 2,981 $ 156 $ (243) Orbital slots 2 15.0 years 5,825 — — — — — Trademarks and trade names 37.1 years 20,016 1,518 (442) 18,359 853 (6) Distribution network 10.0 years 18,414 4,621 — 18,138 2,793 — Released television and film content 17.5 years 10,940 6,240 — 10,941 4,974 — Customer lists and relationships 9.3 years 4,100 1,645 (460) 20,304 14,773 (281) Other 21.3 years 11,311 2,615 (5) 11,427 1,843 (3) Total 22.3 years $ 73,585 $ 16,910 $ (1,328) $ 82,150 $ 25,392 $ (533) 1 Includes $1,561 of wireless license renewals in Mexico in 2019. 2 Changed from indefinite-lived January 1, 2020. Indefinite-lived intangible assets not subject to amortization, net of currency translation adjustment: Licenses: Wireless licenses $ 85,728 $ 83,623 Orbital slots 1 — 11,702 Trade names 5,241 6,067 Total $ 90,969 $ 101,392 1 Changed to amortized January 1, 2020. 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 $8,239 for the year ended December 31, 2020, $7,932 for the year ended December 31, 2019 and $8,347 for the year ended December 31, 2018. Amortization expense is estimated to be $5,987 in 2021, $5,363 in 2022, $4,846 in 2023, $4,302 in 2024 and $4,046 in 2025.

Equity Method Investments

Equity Method Investments	12 Months Ended
	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	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. In May 2020, we acquired the remaining interest in HBO LAG and fully consolidated that entity. In October 2020, we sold our ownership interest in CME. (See Note 6) In 2019, we sold our investments in Hudson Yards and Hulu. (See Note 6) In 2018, we acquired Time Warner, which included various equity method investments. The difference between the fair values and the proportional carrying amounts of those investments’ net assets primarily related to investments in CME (sold in 2020) and HBO LAG (consolidated in 2020). (See Note 6) Our investments in equity affiliates at December 31, 2020 primarily include our interests in SKY Mexico and The CW Network. SKY Mexico We hold a 41.3% interest in SKY Mexico, which is a leading pay-TV provider in Mexico. The CW Network (The CW) We hold a 50.0% interest in The CW, which is an advertising supported broadcasting and licensing joint venture between Warner Bros. and CBS Corporation. The following table is a reconciliation of our investments in equity affiliates as presented on our consolidated balance sheets: 2020 2019 Beginning of year $ 3,695 $ 6,245 Additional investments 178 448 Acquisition of remaining interest in HBO LAG (1,141) — Disposition of CME (749) — Disposition of Hudson Yards — (1,681) Disposition of Hulu — (689) Disposition of Game Show Network — (288) Equity in net income (loss) of affiliates 95 6 Dividends and distributions received (133) (301) Currency translation adjustments (10) (10) Impairments (146) — Other adjustments (9) (35) End of year $ 1,780 $ 3,695

Inventories And Theatrical Film

Inventories And Theatrical Film And Television Production Costs	12 Months Ended
	Dec. 31, 2020
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 of our programming inventory costs from “Other current assets” to “Other Assets” in connection with the adoption of ASU 2019-2 (see Note 1). In the fourth quarter of 2020, we recognized an impairment of $524 based on a change in these estimates for various film titles. This change in estimates was driven by the continued shutdown of theaters during the pandemic, including the resurgence of an outbreak in the fourth quarter and the impact of our decision to release our 2021 movies in theaters and on HBO Max at the same time. The following table summarizes inventories and theatrical film and television production costs as of December 31: 2020 2019 Inventories: Programming costs, less amortization 1 $ 6,010 $ 4,151 Other inventory, primarily DVD and Blu-ray Discs 103 96 Total inventories 6,113 4,247 Less: current portion of inventory (103) (96) Total noncurrent inventories 6,010 4,151 Theatrical film production costs: 2 Released, less amortization 487 392 Completed and not released 616 437 In production 1,130 1,475 Development and pre-production 190 171 Television production costs: 2 Released, less amortization 2,495 2,199 Completed and not released 1,381 1,344 In production 2,353 2,208 Development and pre-production 90 57 Total theatrical film and television production costs 8,742 8,283 Total noncurrent inventories and theatrical film and television production costs $ 14,752 $ 12,434 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 $4,699 and $5,967 of acquired film and television library intangible assets as of December 31, 2020, and 2019, respectively, which are included in “Other Intangible Assets – Net” on our consolidated balance sheets. Approximately 90% of unamortized film costs for released theatrical and television content are expected to be amortized within three years from December 31, 2020. In addition, approximately $3,111 of the total $5,171 film costs of released and completed and not released theatrical and television product are expected to be amortized during 2021.

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	NOTE 12. DEBT Long-term debt of AT&T and its subsidiaries, including interest rates and maturities, is summarized as follows at December 31: 2020 2019 Notes and debentures Interest Rates Maturities 1 0.98% - 2.99% 2020 - 2039 $ 25,549 $ 17,404 3.00% - 4.99% 2020 - 2050 110,317 102,595 5.00% - 6.99% 2020 - 2095 24,259 34,513 7.00% - 9.15% 2020 - 2097 5,006 5,050 Credit agreement borrowings 300 4,969 Fair value of interest rate swaps recorded in debt 20 26 165,451 164,557 Unamortized (discount) premium - net (9,710) (2,996) Unamortized issuance costs (532) (452) Total notes and debentures 155,209 161,109 Finance lease obligations 2,036 2,034 Total long-term debt, including current maturities 157,245 163,143 Current maturities of long-term debt (3,470) (11,834) Total long-term debt $ 153,775 $ 151,309 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, Swiss franc and Brazilian real denominated debt of approximately $43,399 and $42,485 at December 31, 2020 and 2019, respectively. The weighted-average interest rate of our entire long-term debt portfolio, including the impact of derivatives, was approximately 4.1% as of December 31, 2020 and 4.4% as of December 31, 2019. Current maturities of long-term debt include an accreting zero-coupon note that may be redeemed each May, until maturity in 2022. If the zero-coupon note (issued for principal of $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: 2020 2019 Current maturities of long-term debt $ 3,470 $ 11,834 Bank borrowings 1 — 4 Total $ 3,470 $ 11,838 1 Outstanding balance of short-term credit facility of a foreign subsidiary. Financing Activities During 2020, we received net proceeds of $31,988 on the issuance of $32,241 in long-term debt in various markets, with an average weighted maturity of approximately 20 years and a weighted average interest rate of 3.2%. We repaid $39,758 in borrowings of various notes with a weighted average coupon of 3.2%. Tender Offers and Debt Exchanges In August 2020, we repurchased $11,384 of AT&T global notes and subsidiary notes due 2021 to 2025 through cash tender offers. In September 2020, we exchanged $17,677 of AT&T and subsidiary notes, with interest rates ranging from 4.350% to 8.750% and original maturities ranging from 2031 to 2058 for $1,459 of cash and $21,500 of three new series of AT&T Inc. global notes, with interest rates ranging from 3.500% to 3.650% and maturities ranging from 2053 to 2059. In December 2020, we also exchanged $8,280 of AT&T and subsidiary notes, with interest rates ranging from 2.950% to 7.125% and original maturities ranging from 2026 to 2048 for $8 of cash and $9,678 of two new series of AT&T global notes, with interest rates of 2.550% and 3.800% and maturities of 2033 and 2057, respectively. As of December 31, 2020 and 2019, 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, 2020, and the corresponding weighted-average interest rate scheduled for repayment are as follows: 2021 2022 2023 2024 2025 Thereafter Debt repayments 1 $ 3,418 $ 5,951 $ 7,779 $ 7,849 $ 6,389 $ 134,268 Weighted-average interest rate 3.8 % 3.3 % 3.4 % 3.3 % 3.9 % 4.2 % 1 Debt repayments represent maturity value and assume putable debt is redeemed at the next opportunity. Foreign debt includes the impact from hedges, when applicable. Credit Facilities General In September 2019, we entered into and drew on a $1,300 term loan credit agreement containing (i) a 1.25 year $400 facility due in 2020, (ii) a 2.25 year $400 facility due in 2021, and (iii) a 3.25 year $500 facility due in 2022, with Bank of America, N.A., as agent. These facilities were repaid and terminated in the second quarter of 2020. In April 2020, we entered into and drew on a $5,500 Term Loan Credit Agreement (Term Loan) with 11 commercial banks and Bank of America, N.A. as lead agent. We repaid and terminated the Term Loan in May 2020. On January 29, 2021, we entered into a $14,700 Term Loan Credit Agreement (Term Loan), with Bank of America, N.A., as agent. The Term Loan is available for a single draw at any time before May 29, 2021. The proceeds will be used for general corporate purposes, which may include among other things, financing acquisitions of additional spectrum. The entire principal amount of the Term Loan will be due and payable 364 days after the date on which the borrowing is made. At January 31, 2021, we had approximately $6,100 of commercial paper outstanding. Revolving Credit Agreements In November 2020, we amended one of our $7,500 revolving credit agreements by extending the termination date. In total, we have two $7,500 revolving credit agreements, totaling $15,000, with one terminating on December 11, 2023 and the other terminating on November 17, 2025. No amounts were outstanding under either agreement as of December 31, 2020. Each of the credit 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. The obligations of the lenders under two revolving credit agreements to provide advances will terminate on December 11, 2023, and November 17, 2025, 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 our 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% or 0.125% per annum of the amount of the lender commitments, depending on AT&T’s credit rating.

Fair Value Measurements And Dis

Fair Value Measurements And Disclosure	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements And Disclosure	NOTE 13. FAIR VALUE MEASUREMENTS AND DISCLOSURE The Fair Value Measurement and Disclosure framework in ASC 820, “Fair Value Measurement,” 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, 2019. 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, 2020 December 31, 2019 Carrying Fair Carrying Fair Notes and debentures 1 $ 155,209 $ 187,224 $ 161,109 $ 182,124 Bank borrowings — — 4 4 Investment securities 2 3,249 3,249 3,723 3,723 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, 2020, and December 31, 2019. Derivatives designated as hedging instruments are reflected as “Other assets,” “Other noncurrent liabilities,” “Other current assets” and “Accounts payable and accrued liabilities” on our consolidated balance sheets. December 31, 2020 Level 1 Level 2 Level 3 Total Equity Securities Domestic equities $ 1,010 $ — $ — $ 1,010 International equities 180 — — 180 Fixed income equities 236 — — 236 Available-for-Sale Debt Securities — 1,479 — 1,479 Asset Derivatives Cross-currency swaps — 1,721 — 1,721 Foreign exchange contracts — 6 — 6 Liability Derivatives Cross-currency swaps — (1,814) — (1,814) Foreign exchange contracts — (9) — (9) 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) 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, 2020 2019 2018 Total gains (losses) recognized on equity securities $ 171 $ 301 $ (130) Gains (losses) recognized on equity securities sold (25) 100 (10) Unrealized gains (losses) recognized on equity securities held at end of period $ 196 $ 201 $ (120) At December 31, 2020, available-for-sale debt securities totaling $1,479 have maturities as follows - less than one year: $29; one to three years: $159; three to five years: $179; five or more years: $1,112. 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 Periodically, we enter into and designate 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. Unrealized 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 derivatives designated as 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, 2020 and 2019, 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 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 forecasted film production costs and film tax incentives 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, changes in fair value are reported as a component of accumulated OCI and are 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 $92 from accumulated OCI to “Interest expense” due to the amortization of net losses on historical interest rate locks. We settled all interest rate locks in May 2020 in conjunction with the issuance of fixed rate debt obligations that the interest rate locks were hedging and paid $731 that was largely offset by the return of collateral at the time of settlement. Cash flows from the interest rate lock settlements and return of collateral were reported as financing activities in our statement of cash flows, consistent with our accounting policy for these instruments. 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 sheets. Net losses on net investment hedges recognized in accumulated OCI for 2020 were $147. 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, 2020, we had posted collateral of $53 (a deposit asset) and held collateral of $694 (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 $33. If AT&T’s credit rating had been downgraded four ratings 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 $676. If DIRECTV Holdings LLC’s credit rating had been downgraded below BBB- by S&P, we would have been required to post additional collateral of $134. At December 31, 2019, we had posted collateral of $204 (a deposit asset) and held collateral of $44 (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: 2020 2019 Interest rate swaps $ — $ 853 Cross-currency swaps 40,745 42,325 Interest rate locks — 3,500 Foreign exchange contracts 90 269 Total $ 40,835 $ 46,947 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, 2020 2019 2018 Interest rate swaps (Interest expense): Gain (Loss) on interest rate swaps $ (6) $ 58 $ (12) Gain (Loss) on long-term debt 6 (58) 12 In addition, the net swap settlements that accrued and settled in the periods above were offset against “Interest expense.” Cash Flow Hedging Relationships For the years ended December 31, 2020 2019 2018 Cross-currency swaps: Gain (Loss) recognized in accumulated OCI $ (378) $ (1,066) $ (825) Foreign exchange contracts: Gain (Loss) recognized in accumulated OCI 3 10 51 Other income (expense) - net reclassified from accumulated OCI into income (3) 6 39 Interest rate locks: Gain (Loss) recognized in accumulated OCI (648) (84) — Interest income (expense) reclassified from accumulated OCI into income (84) (63) (58) Nonrecurring Fair Value Measurements In addition to assets and liabilities that are recorded at fair value on a recurring basis, impairment indicators may subject goodwill, long-lived assets and film costs to nonrecurring fair value measurements. The implied fair values of the video and Vrio businesses were estimated using both the discounted cash flow as well as market multiple approaches. The fair values of long-lived assets in the video business were determined using a present value approach of probability-weighted expected cash flows. The fair values of film productions were estimated using a discounted cash flow approach. The inputs to all of these approaches are considered Level 3.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 14. INCOME TAXES Significant components of our deferred tax liabilities (assets) are as follows at December 31: 2020 2019 Depreciation and amortization $ 46,952 $ 44,896 Licenses and nonamortizable intangibles 13,930 17,355 Employee benefits (5,279) (5,143) Deferred fulfillment costs 2,691 3,050 Net operating loss and other carryforwards (7,355) (7,301) Other – net 4,562 1,536 Subtotal 55,501 54,393 Deferred tax assets valuation allowance 4,773 4,941 Net deferred tax liabilities $ 60,274 $ 59,334 Noncurrent deferred tax liabilities $ 60,472 $ 59,502 Less: Noncurrent deferred tax assets (198) (168) Net deferred tax liabilities $ 60,274 $ 59,334 At December 31, 2020, we had combined net operating and capital loss carryforwards (tax effected) for federal income tax purposes of $585, state of $916 and foreign of $2,763, expiring through 2040. Additionally, we had federal credit carryforwards of $1,080 and state credit carryforwards of $2,011, expiring primarily through 2040. 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, 2020 and 2019 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. The Company considers other types of unremitted foreign earnings to be indefinitely reinvested. 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 2020 and 2019 is as follows: Federal, State and Foreign Tax 2020 2019 Balance at beginning of year $ 10,979 $ 10,358 Increases for tax positions related to the current year 1,580 903 Increases for tax positions related to prior years 112 1,106 Decreases for tax positions related to prior years (994) (1,283) Lapse of statute of limitations (24) (32) Settlements (1,646) (283) Current year acquisitions — 205 Foreign currency effects (6) 5 Balance at end of year 10,001 10,979 Accrued interest and penalties 2,450 2,708 Gross unrecognized income tax benefits 12,451 13,687 Less: Deferred federal and state income tax benefits (878) (886) Less: Tax attributable to timing items included above (3,588) (4,320) Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year $ 7,985 $ 8,481 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 $702 at December 31, 2020 and $2,584 at December 31, 2019. Accrued interest and penalties included in UTBs were $2,450 as of December 31, 2020, and $2,708 as of December 31, 2019. 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 $149 for 2020, $267 for 2019 and $1,290 for 2018. 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 2012. All audit periods prior to 2005 are closed for federal examination purposes and we have effectively resolved all outstanding audit issues for years through 2010 with the IRS Appeals Division. Those years will be closed as the final paperwork is processed in the coming months. While we do not expect material changes, we are generally unable to estimate the range of impacts on the balance of the remaining uncertain tax positions or the impact on the effective tax rate from the resolution of these issues until each year is closed; 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: 2020 2019 2018 Federal: Current $ (687) $ 584 $ 3,258 Deferred 1,039 1,656 277 352 2,240 3,535 State and local: Current (6) 603 513 Deferred 263 144 473 257 747 986 Foreign: Current 413 605 539 Deferred (57) (99) (140) 356 506 399 Total $ 965 $ 3,493 $ 4,920 “Income Before Income Taxes” in the Consolidated Statements of Income included the following components for the years ended December 31: 2020 2019 2018 U.S. income (loss) before income taxes $ (452) $ 18,301 $ 25,379 Foreign income (loss) before income taxes (2,404) 167 (506) Total $ (2,856) $ 18,468 $ 24,873 A reconciliation of income tax expense (benefit) and the amount computed by applying the statutory federal income tax rate of 21% to income from continuing operations before income taxes is as follows: 2020 2019 2018 Taxes computed at federal statutory rate $ (600) $ 3,878 $ 5,223 Increases (decreases) in income taxes resulting from: State and local income taxes - net of federal income tax benefit 193 611 738 Enactment date and measurement period adjustments from the Act — — (718) Tax on foreign investments (141) (115) (466) Noncontrolling interest (285) (230) (121) Permanent items and R&D credit (239) (285) (189) Audit resolutions (112) (156) 544 Divestitures 107 — — Goodwill impairment 1 2,120 — — Other - net (78) (210) (91) Total $ 965 $ 3,493 $ 4,920 Effective Tax Rate (33.8) % 18.9 % 19.8 % 1 Goodwill impairments are not deductible for tax purposes.

Pension And Postretirement Bene

Pension And Postretirement Benefits	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Pension And Postretirement Benefits	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. During the fourth quarter of 2020, we committed to, and reflected in our results, plan changes impacting retiree life and death coverage and health and medical subsidy benefits. Changes were also communicated that impact future pension accruals for certain management employees. These plan changes align our benefit plans to, or above market level. 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 offered certain terminated vested pension plan participants the opportunity to receive their benefit as a lump sum. During the fourth quarter of 2019, we committed to plan changes impacting the cost of postretirement health and welfare benefits, which were reflected in our results. Future retirees will not receive health retirement subsidies toward post-Medicare coverage but have access to a new cost-efficient comprehensive plan. 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 plans to employee service. The following table presents the change in the projected benefit obligation for the years ended December 31: Pension Benefits Postretirement Benefits 2020 2019 2020 2019 Benefit obligation at beginning of year $ 59,873 $ 55,439 $ 16,041 $ 19,378 Service cost - benefits earned during the period 1,029 1,019 53 71 Interest cost on projected benefit obligation 1,687 1,960 416 675 Amendments (340) — (2,655) (4,590) Actuarial (gain) loss 5,054 7,734 1,423 2,050 Special termination benefits — 81 — — Benefits paid (5,124) (6,356) (1,370) (1,543) Curtailment (1) — — — Plan transfers (20) (4) 20 — Benefit obligation at end of year $ 62,158 $ 59,873 $ 13,928 $ 16,041 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 2020 2019 2020 2019 Fair value of plan assets at beginning of year $ 53,530 $ 51,681 $ 4,145 $ 4,277 Actual return on plan assets 6,199 8,207 302 609 Benefits paid 1 (5,124) (6,356) (1,029) (941) Contributions 2 2 425 200 Plan transfers (1) (4) — — Fair value of plan assets at end of year 54,606 53,530 3,843 4,145 Unfunded status at end of year 2 $ (7,552) $ (6,343) $ (10,085) $ (11,896) 1 At our discretion, certain postretirement benefits may be paid from our 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 2020 2019 2020 2019 Current portion of employee benefit obligation 1 $ — $ — $ (1,213) $ (1,365) Employee benefit obligation 2 (7,552) (6,343) (8,872) (10,531) Net amount recognized $ (7,552) $ (6,343) $ (10,085) $ (11,896) 1 Included in “Accounts payable and accrued liabilities.” 2 Included in “Postemployment benefit obligation,” combined with international pension obligations and other postemployment obligations of $553 and $1,299 at December 31, 2020, respectively. 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 $60,848 at December 31, 2020, and $58,150 at December 31, 2019. Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Income Periodic Benefit Costs The service cost component of net periodic pension cost (benefit) is recorded in operating expenses in the consolidated statements of income while the remaining components are recorded in “Other income (expense) – net.” Our combined net pension and postretirement cost (credit) recognized in our consolidated statements of income was $711, $2,762 and $(4,251) for the years ended December 31, 2020, 2019 and 2018. The following table presents the components of net periodic benefit cost (credit): Pension Benefits 1 Postretirement Benefits 2020 2019 2018 2020 2019 2018 Service cost – benefits earned during the period $ 1,029 $ 1,019 $ 1,116 $ 53 $ 71 $ 109 Interest cost on projected benefit obligation 1,687 1,960 2,092 416 675 778 Expected return on assets (3,557) (3,561) (3,190) (178) (227) (304) Amortization of prior service credit (113) (113) (115) (2,329) (1,820) (1,635) Actuarial (gain) loss 2,404 3,088 (812) 1,299 1,670 (2,290) Net pension and postretirement cost (credit) $ 1,450 $ 2,393 $ (909) $ (739) $ 369 $ (3,342) 1 Net periodic pension cost (credit) excludes immediate cost recognized due to special events: curtailment gain of ($1) in 2020 and special termination benefits of $81 in 2019. 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 2020 2019 2018 2020 2019 2018 Balance at beginning of year $ 361 $ 447 $ 571 $ 8,171 $ 6,086 $ 6,456 Prior service (cost) credit 250 — (37) 2,001 3,457 864 Amortization of prior service credit (86) (86) (87) (1,756) (1,372) (1,234) Total recognized in other comprehensive (income) loss 164 (86) (124) 245 2,085 (370) Balance at end of year $ 525 $ 361 $ 447 $ 8,416 $ 8,171 $ 6,086 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 2020 2019 2018 2020 2019 2018 Weighted-average discount rate for determining benefit obligation at December 31 2.70 % 3.40 % 4.50 % 2.40 % 3.20 % 4.40 % Discount rate in effect for determining service cost 1, 2 3.60 % 4.10 % 4.20 % 3.50 % 4.40 % 4.30 % Discount rate in effect for determining interest cost 1,2 2.90 % 3.50 % 3.80 % 2.70 % 3.70 % 3.60 % Weighted-average interest credit rate for cash balance pension programs 3 3.10 % 3.30 % 3.70 % — % — % — % Long-term rate of return on plan assets 7.00 % 7.00 % 7.00 % 4.75 % 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 2.70% and 2.40% respectively, at December 31, 2020, 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, 2020, when compared to the year ended December 31, 2019, we decreased our pension discount rate by 0.70%, resulting in an increase in our pension plan benefit obligation of $5,594 and decreased our postretirement discount rate by 0.80%, resulting in an increase in our postretirement benefit obligation of $1,311. For the year ended December 31, 2019, 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 rates by 1.20%, resulting in an increase in our postretirement benefit obligation of $2,399. 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 2021, our expected long-term rate of return is 6.75% on pension plan assets and 4.50% on postretirement plan assets. Our expected long-term rates of return on plan assets were adjusted downward by 0.25% for 2021, with pension reducing from 7.00% to 6.75% and postretirement from 4.75% to 4.50%. This update to our asset return assumptions was due to economic forecasts, a change in the asset mix, and holding more fixed income securities in the pension plan and more cash and short-term securities in our VEBA trusts. 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 2021 combined pension and postretirement cost to increase $277. 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 2020 and 2019 reflects the long-term average rate of salary increases. 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 our assessment of historical experience, expectations of healthcare industry inflation and recent prescription drug cost experience, our 2021 assumed annual healthcare prescription drug cost trend and medical cost trend for eligible participants will remain at 4.00% annual and ultimate rate. For 2020, our assumed annual healthcare prescription drug cost trend and medical cost trend for eligible participants was decreased from an annual and ultimate trend rate of 4.50% to an annual and ultimate trend rate of 4.00%. This change in assumption decreased our obligation by $102 at December 31, 2019. In addition to the healthcare cost trend, we assumed an annual 2.50% growth in administrative expenses and an annual 3.00% growth in dental claims. 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 2021. 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 discretionary contributions of $425 in December 2020 and $200 in December 2019 to our postretirement plan. 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 2020 2019 Target 2020 2019 Equity securities: Domestic 16 % - 26 % 19 % 17 % 14 % - 24 % 19 % 20 % International 10 % - 20 % 15 12 9 % - 19 % 14 12 Fixed income securities 37 % - 47 % 35 35 40 % - 50 % 45 52 Real assets 8 % - 18 % 8 9 — % - 6 % 1 1 Private equity 5 % - 15 % 9 8 — % - 6 % 1 2 Preferred interest 6 % - 16 % 10 17 — % - — % — — Other — % - 5 % 4 2 15 % - 25 % 20 13 Total 100 % 100 % 100 % 100 % The pension trust holds a preferred equity interest valued at $5,771 in AT&T Mobility II LLC (Mobility II), the primary holding company for our wireless business (see Note 17). During 2020, the trust sold a portion of this preferred interest valued at $2,885 to third party investors. The preferred equity interest was valued at $8,806 as of December 31, 2019. At December 31, 2020, AT&T securities represented 11% of assets held by our pension trust, including the preferred interest in Mobility II, and 1% 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 in Mobility II 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 the 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, 2020: Pension Assets and Liabilities at Fair Value as of December 31, 2020 Level 1 Level 2 Level 3 Total Non-interest bearing cash $ 173 $ — $ — $ 173 Interest bearing cash 7 — — 7 Foreign currency contracts — 3 — 3 Equity securities: Domestic equities 9,784 — 11 9,795 International equities 4,821 11 12 4,844 Preferred interest — — 5,771 5,771 Fixed income securities: Corporate bonds and other investments — 11,043 52 11,095 Government and municipal bonds — 6,039 — 6,039 Mortgage-backed securities — 442 1 443 Real estate and real assets — — 2,544 2,544 Securities lending collateral 621 1,435 — 2,056 Receivable for variation margin 23 — — 23 Assets at fair value 15,429 18,973 8,391 42,793 Investments sold short and other liabilities at fair value (450) (8) (1) (459) Total plan net assets at fair value $ 14,979 $ 18,965 $ 8,390 $ 42,334 Assets held at net asset value practical expedient Private equity funds 5,154 Real estate funds 1,694 Commingled funds 7,706 Total assets held at net asset value practical expedient 14,554 Other assets (liabilities) 1 (2,282) Total Plan Net Assets $ 54,606 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, 2020 Level 1 Level 2 Level 3 Total Interest bearing cash $ 497 $ 302 $ — $ 799 Equity securities: Domestic equities 363 — — 363 International equities 282 — — 282 Fixed income securities: Corporate bonds and other investments 5 307 3 315 Government and municipal bonds 6 132 1 139 Mortgage-backed securities — 94 — 94 Securities lending collateral — 28 — 28 Assets at fair value 1,153 863 4 2,020 Securities lending payable and other liabilities (1) (29) — (30) Total plan net assets at fair value $ 1,152 $ 834 $ 4 $ 1,990 Assets held at net asset value practical expedient Commingled funds 1,843 Private equity 24 Real estate funds 22 Total assets held at net asset value practical expedient 1,889 Other assets (liabilities) 1 (36) Total Plan Net Assets $ 3,843 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, 2020: Pension Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 8,816 $ 6 $ 2,817 $ 11,639 Realized gains (losses) (150) — 255 105 Unrealized gains (losses) 3 — (178) (175) Transfers in 4 51 36 91 Transfers out — (3) — (3) Purchases 9,114 1 223 9,338 Sales (11,994) (2) (609) (12,605) Balance at end of year $ 5,793 $ 53 $ 2,544 $ 8,390 Postretirement Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ — $ 32 $ — $ 32 Transfers in — 3 — 3 Transfers out — (11) — (11) Sales — (20) — (20) Balance at end of year $ — $ 4 $ — $ 4 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 Estimated Future Benefit Payments Expected benefit payments are estimated using the same assumptions used in determining our benefit obligation at December 31, 2020. 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 2021 $ 5,391 $ 1,392 2022 4,597 1,231 2023 4,428 1,159 2024 4,323 879 2025 4,234 832 Years 2026 - 2030 19,646 3,651 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 $2,687 and the net supplemental retirement pension cost was $330 at and for the year ended December 31, 2020. The projected benefit obligation was $2,605 and the net supplemental retirement pension credit was $438 at and for the year ended December 31, 2019. 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 2.30% at December 31, 2020 and 3.20% at December 31, 2019 were calculated using the same methodologies used in calculating the discount rate for our qualified pension and postretirement benefit plans. Deferred compensation expense was $183 in 2020, $199 in 2019 and $128 in 2018. 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 $814, $793 and $724 for the years ended December 31, 2020, 2019 and 2018.

Share-Based Payments

Share-Based Payments	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Share-Based Payments	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 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-year period, subject to the achievement of certain performance goals. We treat the cash settled portion of these awards as a liability. We grant forfeitable restricted stock and stock units, which are valued at the market price of our common stock at the date of grant and predominantly vest over a four 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: 2020 2019 2018 Performance stock units $ 348 $ 544 $ 301 Restricted stock and stock units 290 273 153 Other nonvested stock units — 7 4 Stock options — (5) 5 Total $ 638 $ 819 $ 463 Income tax benefit $ 157 $ 202 $ 114 A summary of the status of our nonvested stock units as of December 31, 2020, and changes during the year then ended is presented as follows (shares in millions): Nonvested Stock Units Shares Weighted-Average Grant- Nonvested at January 1, 2020 42 $ 33.80 Granted 23 36.90 Vested (18) 35.87 Forfeited (4) 34.48 Nonvested at December 31, 2020 43 $ 34.50 As of December 31, 2020, there was $709 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 2.09 years. The total fair value of shares vested during the year was $647 for 2020, compared to $798 for 2019 and $766 for 2018. It is our intent to satisfy share option exercises using our treasury stock. Cash received from stock option exercises was $65 for 2020, $446 for 2019 and $361 for 2018.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Stockholders' Equity	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 per share. Cumulative perpetual preferred shares consist of the following: • Series A: 48 thousand shares outstanding at December 31, 2020 and December 31, 2019, with a $25,000 per share liquidation preference and a dividend rate of 5.000%. • Series B: 20 thousand shares outstanding at December 31, 2020 and zero outstanding at December 31, 2019, with a €100,000 per share liquidation preference, and an initial rate of 2.875%, subject to reset after May 1, 2025. • Series C: 70 thousand shares outstanding at December 31, 2020 and zero outstanding at December 31, 2019, with a $25,000 per share liquidation preference, and a dividend rate of 4.75%. 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, which was completed in 2020 and (2) March 2014 authorization program for an additional 300 million shares, with approximately 178 million outstanding at December 31, 2020. To implement these authorizations, we used open market repurchases, relying on Rule 10b5-1 of the Securities Exchange Act of 1934, where feasible. We also used accelerated share repurchase agreements with large financial institutions to repurchase our stock. During 2020, we repurchased approximately 142 million shares totaling $5,278 under the March 2013 and March 2014 authorizations. Dividend Declarations In December 2020, AT&T declared a quarterly preferred dividend of $36 and a quarterly common dividend of $0.52 per share of common stock. 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. 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 previously 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. 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. 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. Telco LLC In September 2020, we issued $2,000 nonconvertible cumulative preferred interests out of a newly created limited liability company (Telco LLC) that was formed to hold telecommunication-related assets. Members’ equity in Telco LLC consist of (1) member’s interests, which are held by a consolidated subsidiary of AT&T, and (2) preferred interests (Telco preferred interests), which pay an initial preferred distribution of 4.25% annually, subject to declaration, and subject to reset every seven years. Failure to pay distributions on the Telco preferred interests would not limit cash movements between affiliates, or our ability to declare a dividend on or repurchase AT&T shares. We can call the Telco preferred interests at the issue price beginning seven years from the issuance date. The holders of the Telco preferred interests have the option to require redemption upon the occurrence of certain contingent events, such as the failure of Telco LLC 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, all other holders of equal or more subordinate classes of members equity 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. PR Holdings In 2019, we issued $1,950 nonconvertible cumulative preferred interests in a subsidiary (PR Holdings) that held notes secured by the proceeds from our agreement to sell wireless and wireline operations in Puerto Rico and the U.S. Virgin Islands. These preferred interests were redeemed on November 6, 2020. (See Note 6) The membership interests in PR Holdings consisted of (1) common interests, which were held by consolidated subsidiaries of AT&T, and (2) preferred interests (PR preferred interests). The PR preferred interests paid an initial preferred distribution at an annual rate of 4.75%. Distributions were paid quarterly, subject to declaration.

Sales Of Receivables

Sales Of Receivables	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Sales Of Receivables	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) revolving service and trade receivables. 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 revolving receivables programs are discussed in detail below. The following table sets forth a summary of the receivables and accounts being serviced at December 31: 2020 2019 Equipment Installment Revolving Equipment Installment Revolving Gross receivables: $ 5,565 $ 3,909 $ 4,576 $ 3,324 Balance sheet classification Accounts receivable Notes receivable 2,716 — 2,467 — Trade receivables 554 3,715 477 2,809 Other Assets Noncurrent notes and trade receivables 2,295 194 1,632 515 Outstanding portfolio of receivables derecognized from our consolidated balance sheets 7,827 5,300 9,713 4,300 Cash proceeds received, net of remittances 1 5,646 5,300 7,211 4,300 1 Represents amounts to which financial institutions remain entitled, excluding the deferred purchase price. Equipment Installment Receivables Program 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 through our bankruptcy-remote subsidiary 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 under this program: 2020 2019 2018 Gross receivables sold $ 7,270 $ 9,921 $ 9,391 Net receivables sold 1 7,026 9,483 8,871 Cash proceeds received 6,089 8,189 7,488 Deferred purchase price recorded 1,021 1,451 1,578 Guarantee obligation recorded 157 341 361 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 adjusted for changes in present value of expected cash flows. 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: 2020 2019 2018 Fair value of repurchased receivables $ 1,271 $ 1,418 $ 1,480 Carrying value of deferred purchase price 1,235 1,350 1,393 Gain on repurchases 1 $ 36 $ 68 $ 87 1 These gains are included in “Selling, general and administrative” in the consolidated statements of income. At December 31, 2020 and December 31, 2019, our deferred purchase price receivable was $1,991 and $2,336, respectively, of which $1,476 and $1,569 are included in “Other current assets” on our consolidated balance sheets, with the remainder in “Other Assets.” The guarantee obligation at December 31, 2020 and December 31, 2019 was $228 and $384, respectively, of which $161 and $148 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. Revolving Receivables Program In 2019, we entered into a one-year revolving agreement to transfer up to $4,300 of certain receivables through our bankruptcy-remote subsidiaries to various financial institutions on a recurring basis in exchange for cash equal to the gross receivables transferred. In 2020, we expanded the program limit to $5,300 and we extended the agreement by one year. 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 subsidiaries, which hold additional receivables in the amount of $3,909 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. The obligation is subsequently adjusted for changes in estimated expected credit losses and interest rates. Our maximum exposure to loss related to these receivables transferred is limited to the amount outstanding. The fair value measurement used for the obligation is considered Level 3 under the Fair Value Measurement and Disclosure framework (see Note 13). The following table sets forth a summary of receivables sold: 2020 2019 2018 Gross receivables sold/cash proceeds received 1 $ 15,888 $ 11,989 $ — Collections reinvested under revolving agreement 14,888 7,689 — Net cash proceeds received (remitted) $ 1,000 $ 4,300 $ — Net receivables sold 2 $ 15,760 $ 11,604 $ — Obligations recorded (reversed) 271 530 — 1 Includes initial sale of receivables of $1,000 and $4,300 for 2020 and 2019, respectively. 2 Receivables net of allowance, return and incentive reserves and imputed interest.

Tower Transaction

Tower Transaction	12 Months Ended
	Dec. 31, 2020
Other Liabilities [Abstract]
Tower Transaction	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 - Net” on our consolidated balance sheets and depreciate them accordingly. At December 31, 2020 and 2019, the tower assets had a balance of $764 and $804, respectively. Our depreciation expense for these assets was $39 for each of 2020, 2019 and 2018. Payments made to Crown Castle under this arrangement were $248 for 2020. At December 31, 2020, the future minimum payments under the sublease arrangement are $253 for 2021, $258 for 2022, $264 for 2023, $269 for 2024, $274 for 2025 and $856 thereafter.

FirstNet

FirstNet	12 Months Ended
	Dec. 31, 2020
Contractors [Abstract]
FirstNet	NOTE 20. FIRSTNET In 2017, the First Responder Network Authority (FirstNet) selected AT&T to build and manage the first nationwide broadband network dedicated to America’s first responders. Under the 25-year agreement, FirstNet provides 20 MHz of valuable telecommunications spectrum and success-based payments of $6,500 over the first five years to support network buildout. We are required to construct a network that achieves coverage and nationwide interoperability requirements and 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 own and operate, which we estimate in the $3,000 or less range over the life of the 25-year contract. After FirstNet’s operating expenses are paid, we anticipate the remaining amount, expected to be in the $15,000 range, will be reinvested into the network. During 2020, we submitted $120 in sustainability payments, with future payments under the agreement of $120 for 2021; $195 for 2022, 2023, 2024 and 2025; and $16,620 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, 2020, we have collected approximately $5,000 for the completion of certain tasks and anticipate collecting the remainder of the $6,500 as we achieve milestones set out by FirstNet over the next two years. We also expect to receive approximately $200 over the next few years from FirstNet for reinvestment above the original success-based payments.

Contingent Liabilities

Contingent Liabilities	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	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 $20,274 in 2021, $21,275 in total for 2022 and 2023, $11,142 in total for 2024 and 2025 and $17,919 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, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Additional Financial Information	NOTE 22. ADDITIONAL FINANCIAL INFORMATION December 31, Consolidated Balance Sheets 2020 2019 Accounts payable and accrued liabilities: Accounts payable $ 31,836 $ 29,640 Accrued payroll and commissions 2,988 3,126 Current portion of employee benefit obligation 1,415 1,528 Accrued participations and residuals 2,708 2,852 Accrued interest 2,454 2,498 Other 7,631 6,312 Total accounts payable and accrued liabilities $ 49,032 $ 45,956 Consolidated Statements of Income 2020 2019 2018 Advertising expense $ 5,253 $ 6,121 $ 5,100 Interest expense incurred $ 8,048 $ 8,622 $ 8,450 Capitalized interest (123) (200) (493) Total interest expense $ 7,925 $ 8,422 $ 7,957 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 2020 2019 2018 2017 Cash and cash equivalents $ 9,740 $ 12,130 $ 5,204 $ 50,498 Restricted cash in Other current assets 9 69 61 6 Restricted cash in Other Assets 121 96 135 428 Cash and cash equivalents and restricted cash $ 9,870 $ 12,295 $ 5,400 $ 50,932 The following table summarizes cash paid during the periods for interest and income taxes: Consolidated Statements of Cash Flows 2020 2019 2018 Cash paid (received) during the year for: Interest $ 8,237 $ 8,693 $ 8,818 Income taxes, net of refunds 993 1,421 (354) Spectrum acquisitions 1,613 1,576 521 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 in our statements of cash flows when paid. We recorded $4,664 of vendor financing commitments related to capital investments in 2020, $2,632 in 2019 and $2,162 in 2018.

Subsequent Events (Unaudited)

Subsequent Events (Unaudited)	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events (Unaudited)	NOTE 23. SUBSEQUENT EVENTS (UNAUDITED) WarnerMedia On May 17, 2021, we entered into an agreement to combine our WarnerMedia segment, subject to certain exceptions, with a subsidiary of Discovery, Inc. (Discovery). The agreement is structured as a Reverse Morris Trust transaction, under which WarnerMedia will be distributed to AT&T’s shareholders via a pro rata dividend, an exchange offer, or a combination of both, and combined with Discovery. The transaction is expected to be tax-free to AT&T and AT&T’s shareholders. AT&T will receive approximately $43,000 (subject to adjustment) in a combination of cash, debt securities, and WarnerMedia’s retention of certain debt, and AT&T’s shareholders will receive stock representing approximately 71% of the new company; Discovery shareholders will own approximately 29% of the new company. The transaction is expected to close in mid-2022, subject to approval by Discovery shareholders and customary closing conditions, including receipt of regulatory approvals. No vote is required by AT&T shareholders. The merger agreement contains certain customary termination rights for AT&T and Discovery, including, without limitation, a right for either party to terminate if the transaction is not completed on or before July 15, 2023. Termination under specified circumstances will require Discovery to pay AT&T a termination fee of $720 or AT&T to pay Discovery a termination fee of $1,770. Magallanes, Inc (Spinco), a subsidiary of AT&T, entered into a $41,500 commitment letter (Bridge Commitment Letter) on May 17, 2021. On June 4, 2021, Spinco entered into a $10,000 term loan credit agreement and reduced the Bridge Commitment Letter to $31,500. There have been no draws on the Bridge Commitment Letter or term loan credit agreement. The proceeds from these funding arrangements will be used by Spinco, Inc. on the closing date to make the special cash payment and to otherwise fund the transaction. Video Business On February 25, 2021, we signed an agreement to form a new company named DIRECTV (New DTV) with TPG Capital, which will be jointly governed by a board with representation from both AT&T and TPG. Under the agreement, we will contribute our Video business unit to New DTV for $4,250 of junior preferred units, an additional distribution preference of $4,200 and a 70% economic interest in common units. We expect to receive $7,600 in cash from New DTV at closing. TPG will contribute approximately $1,800 in cash to New DTV for $1,800 of senior preferred units and a 30% economic interest in common units. The remaining $5,800 will be funded by debt taken on by New DTV. As part of this transaction, we agreed to pay net losses under the NFL SUNDAY TICKET contract up to a cap of $2,500 over the remaining period of the contract. The transaction is expected to close in the second half of 2021, pending customary closing conditions. The total of $7,600 of proceeds from the transaction are expected to reduce our total and net debt positions. In the first quarter of 2021, we met the criteria to apply held-for-sale accounting treatment to the assets and liabilities of the U.S. video business, and accordingly began to include the assets in “Other current assets,” and the related liabilities in “Accounts payable and accrued liabilities,” on our consolidated balance sheet at March 31, 2021. The carrying amounts at December 31, 2020 of these assets and liabilities were approximately $16,150 and $4,900, respectively. Given the treatment as held-for-sale, we also reclassified the held-for-sale Video business results from the Communications segment to Corporate and Other beginning in the first quarter of 2021, consistent with historical practice.

Summary Of Significant Accoun_2

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	All significant intercompany transactions are eliminated in the consolidation process. Investments in subsidiaries and partnerships which we do not control but 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	The preparation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions, including potential impacts arising from the COVID-19 pandemic and other estimates of probable losses and expenses, that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Certain prior-period amounts have been conformed to the current period’s presentation.
Credit Losses / Allowance for Credit Losses	Credit Losses As of January 1, 2020, we adopted, through modified retrospective application, the Financial Accounting Standards Board’s (FASB) Accounting Standards Update (ASU) No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” or Accounting Standards Codification (ASC) 326 (ASC 326), which replaces the incurred loss impairment methodology under prior GAAP with an expected credit loss model. ASC 326 affects trade receivables, loans, contract assets, certain beneficial interests, off-balance-sheet credit exposures not accounted for as insurance and other financial assets that are not subject to fair value through net income, as defined by the standard. Under the expected credit loss model, we are required to consider future economic trends to estimate expected credit losses over the lifetime of the asset. Upon adoption on January 1, 2020, we recorded a $293 reduction to “Retained earnings,” $395 increase to “Allowances for credit losses” applicable to our trade and loan receivables, $10 reduction of contract assets, $105 reduction of net deferred income tax liability and $7 reduction of “Noncontrolling interest.” Our adoption of ASC 326 did not have a material impact on our financial statements. Allowance for Credit Losses We record expense to maintain an allowance for credit losses 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 allowances for trade receivables and loans, we consider the probability of recoverability of accounts receivable based on past experience, taking into account current collection trends and general economic factors, including bankruptcy rates. We also consider future economic trends to estimate expected credit losses over the lifetime of the asset. 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.
Leases	Leases As of January 1, 2019, we adopted, with modified retrospective application, the FASB's ASU No. 2016-02, “Leases (Topic 842)” (ASC 842), which replaces existing leasing rules with a comprehensive lease measurement and recognition standard and expanded disclosure requirements (see Note 8). ASC 842 requires lessees to recognize most leases on their balance sheets as liabilities, with corresponding “right-of-use” assets. For income statement recognition purposes, leases are classified as either a finance or an operating lease without relying upon bright-line tests. The key change upon adoption of the standard was balance sheet recognition of operating leases, 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 but recorded a cumulative effect adjustment to retained earnings on January 1, 2019. We elected the package of practical expedients permitted under the transition guidance within the new standard, which, among other things, allowed us to carry forward our historical lease classification. We also elected the practical expedient related to land easements, allowing us to carry forward our accounting treatment for land easements on existing agreements that were not accounted for as leases. We excluded leases with original terms of one year or less. Additionally, we elected to not separate lease and non-lease components for certain classes of assets. Our accounting for finance leases did not change from our prior accounting for capital leases.
Deferral of Episodic Television and Film Costs, Equipment Inventory, and Licensed Programming Inventory Cost Recognition and Impairment	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 as of January 1, 2019, with prospective application. The standard eliminates certain revenue-related constraints on capitalization of inventory costs for episodic television that existed under prior guidance. In addition, the balance sheet classification requirements that existed in prior guidance for film production costs and programming inventory were eliminated. As of January 1, 2019, we reclassified $2,274 of our programming inventory costs from “Other current assets” to “Other Assets” in accordance with the guidance (see Note 11). This change in accounting did 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 $3,592 at December 31, 2020 and $2,864 at December 31, 2019. 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 are determined using the film forecast computation method. Under this method, the amortization of capitalized costs and the accrual of participations and residuals are 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. (See Note 11) 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 generally does not 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	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 method, which does not allow us to adjust prior periods. We applied the rules to all open contracts existing as of January 1, 2018, recording an increase of $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) We report our revenues net of sales taxes and record certain regulatory fees, primarily Universal Service Fund (USF) fees, on a net basis. No customer accounted for more than 10% of consolidated revenues in 2020, 2019 or 2018. 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, facilitates 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 separate performance obligation (e.g., equipment associated with certain video services), we allocate the total transaction price to the related service. When equipment is a separate 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 relationship 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.
Financial Instruments	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 prospective ly record changes in the fair value of our equity investments, except for those accounted for under the equity method, in net income instead of in accumulated other comprehensive income (accumulated OCI). As of January 1, 2018, we recorded an increase of $658 in retained earnings for the cumulative effect of the adoption of ASU 2016-01, with an offset to accumulated OCI.
Income Taxes	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), which was enacted on December 22, 2017, 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. 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, as allowed by the Securities and Exchange Commission (SEC) in Staff Accounting Bulletin (SAB) 118. (See Note 14)
Cash And Cash Equivalents	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, 2020, we held $2,842 in cash and $6,898 in money market funds and other cash equivalents. Of our total cash and cash equivalents, $2,205 resided in foreign jurisdictions, some of which is subject to restrictions on repatriation.
Property, Plant and Equipment	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 an impairment of long-lived assets of the video business and other network 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	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 - Net” 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 to seven-year period, reflecting the estimated period during which these assets will remain in service.
Goodwill and Other Intangible Assets	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 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. During the first quarter of 2020, in conjunction with the nationwide launch of AT&T TV and our customers’ continued shift from linear to streaming video services, we reassessed the estimated economic lives and renewal assumptions for our orbital slot licenses. As a result, we have changed the estimated lives of our orbital slot licenses from indefinite to finite-lived, effective January 1, 2020, and began amortizing these licenses using the sum-of-months-digits method over their average remaining economic life of 15 years at January 1, 2020. This change in accounting increased amortization expense $1,504, or $0.16 per diluted share available to common stock for 2020. 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. During the first quarter of 2020, we reassessed and changed the estimated economic lives of certain trade names in our Latin America business from indefinite to finite-lived and began amortizing them using the straight-line method over their average remaining economic life of 15 years. This change had an insignificant impact on our financial statements. 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. Prior to 2020, orbital slots were 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). As of January 1, 2020, on a prospective basis, orbital slots are amortized using the sum-of-the-months-digits method of amortization over their average remaining economic life. 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. These assets, along with other long-lived assets, are reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable.
Advertising Costs	Advertising Costs We expense advertising costs for products and services or for promoting our corporate image as incurred (see Note 22).
Foreign Currency Translation	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 use 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	Pension and Other Postretirement Benefits See Note 15 for a comprehensive discussion of our pension and postretirement benefits, 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	New Accounting Standards 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 do not expect ASU 2019-12 to have a material impact on our financial statements. Reference Rate Reform In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting” (ASU 2020-04, as amended), which provides optional expedients, and allows for certain exceptions to existing GAAP, for contract modifications triggered by the expected market transition of certain benchmark interest rates to alternative reference rates. ASU 2020-04 applies to contracts, hedging relationships, certain derivatives and other arrangements that reference the London Interbank Offering Rate (LIBOR) or any other rates ending after December 31, 2022. ASU 2020-04 became effective immediately. We are evaluating the impact of our adoption of ASU 2020-04, including optional expedients, to our financial statements. Convertible Instruments In August 2020, the FASB issued ASU No. 2020-06, “Debt—Debt With Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity” (ASU 2020-06), which eliminated certain separation models regarding cash conversion and beneficial conversion features to simplify reporting for convertible instruments as a single liability or equity, with no separate accounting for embedded conversion features. ASU 2020-06 will be effective for fiscal years beginning after December 31, 2021, under modified retrospective or full retrospective application, subject to early adoption in 2021. We are evaluating the impact of our adoption of ASU 2020-06 on our financial statements.
Derivatives, Offsetting Fair Value Amounts	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.
Recognition of Actuarial Gains and Losses	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, 2020
Earnings Per Share [Abstract]
Reconciliation of Numerators and Denominators of Basic and Diluted Earnings Per Share	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, 2020 2019 2018 Numerators Numerator for basic earnings per share: Net Income (Loss) $ (3,821) $ 14,975 $ 19,953 Less: Net Income Attributable to Noncontrolling Interest (1,355) (1,072) (583) Net Income (Loss) Attributable to AT&T (5,176) 13,903 19,370 Less: Preferred Stock Dividends (193) (3) — Net Income (Loss) Attributable to Common Stock (5,369) 13,900 19,370 Dilutive potential common shares: Share-based payment 1 23 21 19 Numerator for diluted earnings per share $ (5,346) $ 13,921 $ 19,389 Denominators (000,000) Denominator for basic earnings per share: Weighted average number of common shares outstanding 7,157 7,319 6,778 Dilutive potential common shares: Share-based payment (in shares) 1 26 29 28 Denominator for diluted earnings per share 7,183 7,348 6,806 Basic Earnings Per Share Attributable to Common Stock $ (0.75) $ 1.90 $ 2.85 Diluted Earnings Per Share Attributable to Common Stock 1 $ (0.75) $ 1.89 $ 2.85 1 For 2020, dilutive potential common shares are not included in the computation of diluted earnings per share because their effect is antidilutive as a result of the net loss.

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated 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 Net Unrealized Net Unrealized Defined Benefit Accumulated Other 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 4 — (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 Other comprehensive income (loss) before reclassifications (870) 78 (811) 2,250 647 Amounts reclassified from accumulated OCI — 1 (15) 1 69 2 (1,841) 3 (1,787) Net other comprehensive income (loss) (870) 63 (742) 409 (1,140) Balance as of December 31, 2020 $ (3,926) $ 111 $ (779) $ 8,924 $ 4,330 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) – net” in the consolidated statements of income (see Note 15). 4 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, 2020
Segment Reporting [Abstract]
Reconciliation of Revenues to Segment Contribution	For the year ended December 31, 2020 Revenues Operations EBITDA Depreciation and Amortization Operating Equity in Net Segment Communications Mobility $ 72,564 $ 42,106 $ 30,458 $ 8,086 $ 22,372 $ — $ 22,372 Business Wireline 25,083 15,303 9,780 5,216 4,564 — 4,564 Consumer Wireline 12,318 8,027 4,291 2,914 1,377 — 1,377 Total Communications 109,965 65,436 44,529 16,216 28,313 — 28,313 WarnerMedia Turner 12,568 6,954 5,614 277 5,337 (2) 5,335 Home Box Office 6,808 6,028 780 98 682 16 698 Warner Bros. 12,154 9,917 2,237 169 2,068 (70) 1,998 Eliminations and other (1,088) (1,320) 232 127 105 74 179 Total WarnerMedia 30,442 21,579 8,863 671 8,192 18 8,210 Latin America Vrio 3,154 2,800 354 520 (166) 24 (142) Mexico 2,562 2,636 (74) 513 (587) — (587) Total Latin America 5,716 5,436 280 1,033 (753) 24 (729) Segment Total 146,123 92,451 53,672 17,920 35,752 $ 42 $ 35,794 Corporate and Other Corporate 1 2,207 4,205 (1,998) 310 (2,308) Video 28,610 24,174 4,436 2,262 2,174 Acquisition-related items — 468 (468) 8,012 (8,480) Certain significant items — 19,156 (19,156) 14 (19,170) Eliminations and consolidations (5,180) (3,615) (1,565) (2) (1,563) AT&T Inc. $ 171,760 $ 136,839 $ 34,921 $ 28,516 $ 6,405 1 Operations and Support Expenses include $2,442 for the reclassification of prior service credit amortization. For the year ended December 31, 2019 Revenues Operations EBITDA Depreciation Operating Equity in Net Segment Communications Mobility $ 71,056 $ 40,681 $ 30,375 $ 8,054 $ 22,321 $ — $ 22,321 Business Wireline 25,901 15,839 10,062 4,925 5,137 — 5,137 Consumer Wireline 13,012 7,775 5,237 2,880 2,357 — 2,357 Total Communications 109,969 64,295 45,674 15,859 29,815 — 29,815 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 Eliminations and other 1,030 304 726 90 636 109 745 Total WarnerMedia 35,259 24,172 11,087 589 10,498 161 10,659 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) Segment Total 152,191 94,930 57,261 17,610 39,651 $ 188 $ 39,839 Corporate and Other Corporate 1 2,203 3,509 (1,306) 645 (1,951) Video 32,124 27,275 4,849 2,461 2,388 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 1 Operations and Support Expenses include $1,934 for the reclassification of prior service credit amortization. For the year ended December 31, 2018 Revenues Operations EBITDA Depreciation Operating Equity in Net Segment Communications Mobility $ 70,521 $ 40,690 $ 29,831 $ 8,263 $ 21,568 $ — $ 21,568 Business Wireline 26,494 16,012 10,482 4,704 5,778 — 5,778 Consumer Wireline 13,108 7,596 5,512 2,623 2,889 — 2,889 Total Communications 110,123 64,298 45,825 15,590 30,235 — 30,235 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 Eliminations and other 1,305 168 1,137 28 1,109 (30) 1,079 Total WarnerMedia 20,585 13,279 7,306 311 6,995 25 7,020 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) Segment Total 138,360 84,735 53,625 17,139 36,486 $ 59 $ 36,545 Corporate and Other Corporate 1 2,481 2,502 (21) 1,637 (1,658) Video 33,363 28,856 4,507 2,698 1,809 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 1 Operations and Support Expenses include $1,753 for the reclassification of prior service credit amortization.
Reconciliation of Segment Contributions to Income Before Income Taxes	The following table is a reconciliation of operating income (loss) to “Income Before Income Taxes” reported in our consolidated statements of income: 2020 2019 2018 Communications $ 28,313 $ 29,815 $ 30,235 WarnerMedia 8,210 10,659 7,020 Latin America (729) (635) (710) Segment Contribution 35,794 39,839 36,545 Reconciling Items: Corporate and Other (2,308) (1,951) (1,658) Video 2,174 2,388 1,809 Merger and integration items (468) (1,032) (1,234) Amortization of intangibles acquired (8,012) (7,460) (6,931) Impairments and abandonments (18,880) (1,458) (46) Gain on spectrum transaction 1 900 — — Employee separation charges and benefit-related (gain) loss (1,177) (624) (587) Other noncash charges (credits), net (13) (43) (111) Natural disaster items — — (181) Segment equity in net income of affiliates (42) (188) (59) Eliminations and consolidations (1,563) (1,516) (1,451) AT&T Operating Income 6,405 27,955 26,096 Interest Expense 7,925 8,422 7,957 Equity in net income (loss) of affiliates 95 6 (48) Other income (expense) - net (1,431) (1,071) 6,782 Income (Loss) Before Income Taxes $ (2,856) $ 18,468 $ 24,873 1 Included as a reduction of “Selling, general and administrative expenses” in the consolidated statements of income.
Schedule of Revenues Earned from Customers and Property, Plant and Equipment by Geographical Areas	The following table sets forth revenues earned from customers, and property, plant and equipment located in different geographic areas: 2020 2019 2018 Revenues Net Property, Plant & Equipment Revenues Net Property, Plant & Equipment Revenues Net Property, United States $ 155,899 $ 121,208 $ 161,689 $ 122,567 $ 154,795 $ 123,457 Europe 5,387 1,152 6,536 1,854 4,073 1,634 Mexico 2,862 3,530 3,198 3,648 3,100 3,467 Brazil 1,807 694 2,797 1,057 2,724 1,213 All other Latin America 2,679 485 3,219 544 3,055 1,217 Asia/Pacific Rim 2,322 203 2,793 390 2,214 408 Other 804 43 961 68 795 77 Total $ 171,760 $ 127,315 $ 181,193 $ 130,128 $ 170,756 $ 131,473
Schedule of Intersegment Revenues, Assets, Investments in Equity Affiliates, and Capital Expenditures by Segment	The following tables present intersegment revenues, assets, investments in equity affiliates and capital expenditures by segment: Intersegment Reconciliation 2020 2019 2018 Intersegment revenues Communications $ 11 $ 26 $ 13 WarnerMedia 3,183 3,318 1,875 Latin America — — — Total Intersegment Revenues 3,194 3,344 1,888 Consolidations 1,986 1,909 1,511 Eliminations and consolidations $ 5,180 $ 5,253 $ 3,399 At or for the years ended December 31, 2020 2019 Assets Investments in Capital Assets Investments in Capital Communications 1 $ 506,102 $ — $ 14,107 $ 492,649 $ — $ 17,410 WarnerMedia 148,037 1,123 699 140,376 3,011 1,205 Latin America 15,811 590 708 20,606 650 757 Corporate and eliminations 1 (144,189) 67 161 (101,962) 34 263 Total $ 525,761 $ 1,780 $ 15,675 $ 551,669 $ 3,695 $ 19,635 1 Amounts above have been updated to reflect the classification of our Video business as held-for-sale (beginning in the first quarter of 2021), which included the recast of historical results to remove Video from our Communications segment and instead report in Corporate and Other.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue by Category and Business Unit	The following tables set forth reported revenue by category and by business unit. Intercompany transactions between segments and the dual reporting of certain advertising revenues are included in “Eliminations and consolidations.” Intercompany transactions between Turner, Home Box Office and Warner Bros., including internal sales to HBO Max that began in the fourth quarter of 2019, are included in “Eliminations and Other.” For the year ended December 31, 2020 Service Revenues Wireless Business Advanced Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 55,251 $ — $ — $ — $ — $ — $ 291 $ — $ 17,022 $ 72,564 Business Wireline — 24,313 — — — — — — 770 25,083 Consumer Wireline — — 8,534 2,213 — — — 1,564 7 12,318 WarnerMedia Turner — — — — 7,613 759 3,941 255 — 12,568 Home Box Office — — — — 6,090 692 — 26 — 6,808 Warner Bros. — — — — 50 11,632 6 466 — 12,154 Eliminations and Other 1 — — — — 12 (3,264) 2,178 (14) — (1,088) Latin America Vrio — — — — 3,154 — — — — 3,154 Mexico 1,656 — — — — — — — 906 2,562 Corporate and Other 528 321 — 554 26,747 — 1,718 661 288 30,817 Eliminations and consolidations 2 — — — — (3,110) — (1,718) (352) — (5,180) Total Operating Revenues $ 57,435 $ 24,634 $ 8,534 $ 2,767 $ 40,556 $ 9,819 $ 6,416 $ 2,606 $ 18,993 $ 171,760 1 Eliminations and other of $3,264 include Warner Bros. content sales of approximately $2,250 with HBO Max, $600 with HBO linear and $300 with Turner. 2 Eliminations and consolidations of $3,110 include approximately $1,500 and $950 of Turner and HBO linear channel distribution arrangements with the Video business, respectively. HBO customer subscriptions were approximately $290 with Mobility and $180 with Consumer Wireline. For the year ended December 31, 2019 Service Revenues Wireless Business Advanced Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 55,039 $ — $ — $ — $ — $ — $ 292 $ — $ 15,725 $ 71,056 Business Wireline — 25,116 — — — — — — 785 25,901 Consumer Wireline — — 8,403 2,573 — — — 2,029 7 13,012 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 1 — — — — 13 (1,058) 2,071 4 — 1,030 Latin America Vrio — — — — 4,094 — — — — 4,094 Mexico 1,863 — — — — — — — 1,006 2,869 Corporate and Other 628 325 — 565 30,451 — 1,672 443 171 34,255 Eliminations and consolidations 2 — — — — (3,249) — (1,672) (332) — (5,253) Total Operating Revenues $ 57,530 $ 25,441 $ 8,403 $ 3,138 $ 44,947 $ 13,880 $ 6,970 $ 3,190 $ 17,694 $ 181,193 1 Eliminations and other of $1,058 include Warner Bros. content sales of approximately $500 with HBO linear and $350 with Turner. 2 Eliminations and consolidations of $3,249 include approximately $1,740 and $1,320 of Turner and HBO linear channel distribution arrangements with the Video business, respectively. For the year ended December 31, 2018 Service Revenues Wireless Business Advanced Legacy Voice & Data Subscription Content Advertising Other Equipment Total Communications Mobility $ 54,063 $ — $ — $ — $ — $ — $ 232 $ — $ 16,226 $ 70,521 Business Wireline — 25,671 — — — — — — 823 26,494 Consumer Wireline — — 7,956 3,042 — — — 2,101 9 13,108 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 1 — — — — 6 (518) 1,807 10 — 1,305 Latin America Vrio — — — — 4,784 — — — — 4,784 Mexico 1,701 — — — — — — — 1,167 2,868 Corporate and Other 718 395 — 288 31,768 — 1,595 845 186 35,795 Eliminations and consolidations 2 — — — — (1,843) — (1,595) 39 — (3,399) Total Operating Revenues $ 56,482 $ 26,066 $ 7,956 $ 3,330 $ 42,170 $ 8,384 $ 4,422 $ 3,535 $ 18,411 $ 170,756 1 Eliminations and other of $518 include Warner Bros. content sales of approximately $225 with HBO linear and $225 with Turner. 2 Eliminations and consolidations of $1,843 include approximately $1,000 and $700 of Turner and HBO linear channel distribution arrangements with the Video business, respectively.
Schedule of Deferred Customer Contract Acquisition and Fulfillment Costs	The following table presents the deferred customer contract acquisition and fulfillment costs included on our consolidated balance sheets at December 31: Consolidated Balance Sheets 2020 2019 Deferred Acquisition Costs Other current assets $ 3,087 $ 2,462 Other Assets 3,198 2,991 Total deferred customer contract acquisition costs $ 6,285 $ 5,453 Deferred Fulfillment Costs Other current assets $ 4,118 $ 4,519 Other Assets 5,634 6,439 Total deferred customer contract fulfillment costs $ 9,752 $ 10,958 The following table presents amortization of deferred customer contract acquisition and fulfillment costs, which are recorded in other cost of revenues in our consolidated statements of income, for the year ended December 31: Consolidated Statements of Income 2020 2019 Deferred acquisition cost amortization $ 2,755 $ 2,174 Deferred fulfillment cost amortization 5,110 4,947
Schedule of Contract Assets and Liabilities	The following table presents contract assets and liabilities on our consolidated balance sheets at December 31: Consolidated Balance Sheets 2020 2019 Contract assets $ 3,501 $ 2,472 Contract liabilities 6,879 6,999

Acquisitions, Dispositions An_2

Acquisitions, Dispositions And Other Adjustments (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Unaudited Pro Forma Consolidated Results of Operations	The following unaudited pro forma consolidated results of operations assume that the acquisition of Time Warner was completed as of January 1, 2017. (Unaudited) 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, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment is summarized as follows at December 31: Lives (years) 2020 2019 Land - $ 2,571 $ 2,651 Buildings and improvements 2-44 39,418 38,924 Central office equipment 1 3-10 95,981 96,061 Cable, wiring and conduit 15-50 75,409 72,042 Satellites 14-17 908 2,489 Other equipment 3-20 90,883 94,951 Software 3-7 18,482 22,244 Under construction - 4,099 4,176 327,751 333,538 Accumulated depreciation and amortization 200,436 203,410 Property, plant and equipment - net $ 127,315 $ 130,128 1 Includes certain network software.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Components of Lease Expense, Supplemental Cash Flow Information Related to Leases, and Supplemental Balance Sheet Information Related to Leases	The components of lease expense were as follows: 2020 2019 Operating lease cost $ 5,896 $ 5,684 Finance lease cost: Amortization of right-of-use assets $ 287 $ 271 Interest on lease obligation 156 169 Total finance lease cost $ 443 $ 440 The following table provides supplemental cash flows information related to leases: 2020 2019 Cash Flows from Operating Activities Cash paid for amounts included in lease obligations: Operating cash flows from operating leases $ 4,852 $ 4,583 Supplemental Lease Cash Flow Disclosures Operating lease right-of-use assets obtained in exchange for new operating lease obligations $ 5,270 $ 7,818 The following tables set forth supplemental balance sheet information related to leases at December 31: 2020 2019 Operating Leases Operating lease right-of-use assets $ 24,714 $ 24,039 Accounts payable and accrued liabilities $ 3,537 3,451 Operating lease obligation 22,202 21,804 Total operating lease obligation $ 25,739 $ 25,255 Finance Leases Property, plant and equipment, at cost $ 3,586 $ 3,534 Accumulated depreciation and amortization (1,361) (1,296) Property, plant and equipment, net $ 2,225 $ 2,238 Current portion of long-term debt $ 189 $ 162 Long-term debt 1,847 1,872 Total finance lease obligation $ 2,036 $ 2,034 2020 2019 Weighted-Average Remaining Lease Term (years) Operating leases 8.5 8.4 Finance leases 9.9 10.3 Weighted-Average Discount Rate Operating leases 4.1 % 4.2 % Finance leases 8.1 % 8.4 %
Schedule of Maturities of Operating Leases	The following table provides the expected future minimum maturities of lease obligations: Operating Leases Finance 2021 $ 4,808 $ 350 2022 4,527 333 2023 4,094 300 2024 3,560 276 2025 2,904 272 Thereafter 11,230 1,609 Total lease payments 31,123 3,140 Less: imputed interest (5,384) (1,104) Total $ 25,739 $ 2,036
Schedule of Maturities of Finance Leases	The following table provides the expected future minimum maturities of lease obligations: Operating Leases Finance 2021 $ 4,808 $ 350 2022 4,527 333 2023 4,094 300 2024 3,560 276 2025 2,904 272 Thereafter 11,230 1,609 Total lease payments 31,123 3,140 Less: imputed interest (5,384) (1,104) Total $ 25,739 $ 2,036

Goodwill And Other Intangible_2

Goodwill And Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Summary Of Changes In Carrying Amount Of Goodwill, By Segment	The following table sets forth the changes in the carrying amounts of goodwill by operating segment: 2020 2019 Balance at Acquisitions Impairments Dispositions, Balance at Balance at Acquisitions Dispositions, Balance at Communications $ 100,234 $ — $ (8,253) $ (5) $ 91,976 $ 100,551 $ — $ (317) $ 100,234 WarnerMedia 42,345 415 — (313) 42,447 42,101 66 178 42,345 Latin America 3,662 — (2,212) (614) 836 3,718 — (56) 3,662 Total $ 146,241 $ 415 $ (10,465) $ (932) $ 135,259 $ 146,370 $ 66 $ (195) $ 146,241
Schedule of Amortized Intangible Assets	Our other intangible assets at December 31 are summarized as follows: 2020 2019 Other Intangible Assets Weighted-Average Life Gross Carrying Accumulated Currency Gross Carrying Accumulated Currency Amortized intangible assets: Wireless licenses 1 24.6 years $ 2,979 $ 271 $ (421) $ 2,981 $ 156 $ (243) Orbital slots 2 15.0 years 5,825 — — — — — Trademarks and trade names 37.1 years 20,016 1,518 (442) 18,359 853 (6) Distribution network 10.0 years 18,414 4,621 — 18,138 2,793 — Released television and film content 17.5 years 10,940 6,240 — 10,941 4,974 — Customer lists and relationships 9.3 years 4,100 1,645 (460) 20,304 14,773 (281) Other 21.3 years 11,311 2,615 (5) 11,427 1,843 (3) Total 22.3 years $ 73,585 $ 16,910 $ (1,328) $ 82,150 $ 25,392 $ (533) 1 Includes $1,561 of wireless license renewals in Mexico in 2019. 2 Changed from indefinite-lived January 1, 2020.
Schedule of Indefinite-Life Intangible Assets Not Subject to Amortization	Indefinite-lived intangible assets not subject to amortization, net of currency translation adjustment: Licenses: Wireless licenses $ 85,728 $ 83,623 Orbital slots 1 — 11,702 Trade names 5,241 6,067 Total $ 90,969 $ 101,392 1 Changed to amortized January 1, 2020.

Equity Method Investments (Tabl

Equity Method Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Reconciliation of Investments In Equity Affiliates	The following table is a reconciliation of our investments in equity affiliates as presented on our consolidated balance sheets: 2020 2019 Beginning of year $ 3,695 $ 6,245 Additional investments 178 448 Acquisition of remaining interest in HBO LAG (1,141) — Disposition of CME (749) — Disposition of Hudson Yards — (1,681) Disposition of Hulu — (689) Disposition of Game Show Network — (288) Equity in net income (loss) of affiliates 95 6 Dividends and distributions received (133) (301) Currency translation adjustments (10) (10) Impairments (146) — Other adjustments (9) (35) End of year $ 1,780 $ 3,695

Inventories And Theatrical Fi_2

Inventories And Theatrical Film And Television Production Costs (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories and Theatrical Film and Television Production Costs	The following table summarizes inventories and theatrical film and television production costs as of December 31: 2020 2019 Inventories: Programming costs, less amortization 1 $ 6,010 $ 4,151 Other inventory, primarily DVD and Blu-ray Discs 103 96 Total inventories 6,113 4,247 Less: current portion of inventory (103) (96) Total noncurrent inventories 6,010 4,151 Theatrical film production costs: 2 Released, less amortization 487 392 Completed and not released 616 437 In production 1,130 1,475 Development and pre-production 190 171 Television production costs: 2 Released, less amortization 2,495 2,199 Completed and not released 1,381 1,344 In production 2,353 2,208 Development and pre-production 90 57 Total theatrical film and television production costs 8,742 8,283 Total noncurrent inventories and theatrical film and television production costs $ 14,752 $ 12,434 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 $4,699 and $5,967 of acquired film and television library intangible assets as of December 31, 2020, and 2019, respectively, which are included in “Other Intangible Assets – Net” on our consolidated balance sheets.

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Summary of Long-Term Debt of AT&T and its Subsidiaries	Long-term debt of AT&T and its subsidiaries, including interest rates and maturities, is summarized as follows at December 31: 2020 2019 Notes and debentures Interest Rates Maturities 1 0.98% - 2.99% 2020 - 2039 $ 25,549 $ 17,404 3.00% - 4.99% 2020 - 2050 110,317 102,595 5.00% - 6.99% 2020 - 2095 24,259 34,513 7.00% - 9.15% 2020 - 2097 5,006 5,050 Credit agreement borrowings 300 4,969 Fair value of interest rate swaps recorded in debt 20 26 165,451 164,557 Unamortized (discount) premium - net (9,710) (2,996) Unamortized issuance costs (532) (452) Total notes and debentures 155,209 161,109 Finance lease obligations 2,036 2,034 Total long-term debt, including current maturities 157,245 163,143 Current maturities of long-term debt (3,470) (11,834) Total long-term debt $ 153,775 $ 151,309 1 Maturities assume putable debt is redeemed by the holders at the next opportunity.
Debt Maturing Within One Year	Debt maturing within one year consisted of the following at December 31: 2020 2019 Current maturities of long-term debt $ 3,470 $ 11,834 Bank borrowings 1 — 4 Total $ 3,470 $ 11,838 1 Outstanding balance of short-term credit facility of a foreign subsidiary.
Long-Term Debt - Scheduled Repayments	Maturities of outstanding long-term notes and debentures, as of December 31, 2020, and the corresponding weighted-average interest rate scheduled for repayment are as follows: 2021 2022 2023 2024 2025 Thereafter Debt repayments 1 $ 3,418 $ 5,951 $ 7,779 $ 7,849 $ 6,389 $ 134,268 Weighted-average interest rate 3.8 % 3.3 % 3.4 % 3.3 % 3.9 % 4.2 % 1 Debt repayments represent maturity value and assume putable debt is redeemed at the next opportunity. Foreign debt includes the impact from hedges, when applicable.

Fair Value Measurements And D_2

Fair Value Measurements And Disclosure (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
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, 2020 December 31, 2019 Carrying Fair Carrying Fair Notes and debentures 1 $ 155,209 $ 187,224 $ 161,109 $ 182,124 Bank borrowings — — 4 4 Investment securities 2 3,249 3,249 3,723 3,723 1 Includes credit agreement borrowings. 2 Excludes investments accounted for under the equity method.
Fair Value Leveling	Following is the fair value leveling for investment securities that are measured at fair value and derivatives as of December 31, 2020, and December 31, 2019. Derivatives designated as hedging instruments are reflected as “Other assets,” “Other noncurrent liabilities,” “Other current assets” and “Accounts payable and accrued liabilities” on our consolidated balance sheets. December 31, 2020 Level 1 Level 2 Level 3 Total Equity Securities Domestic equities $ 1,010 $ — $ — $ 1,010 International equities 180 — — 180 Fixed income equities 236 — — 236 Available-for-Sale Debt Securities — 1,479 — 1,479 Asset Derivatives Cross-currency swaps — 1,721 — 1,721 Foreign exchange contracts — 6 — 6 Liability Derivatives Cross-currency swaps — (1,814) — (1,814) Foreign exchange contracts — (9) — (9) 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)
Components Comprising Total Gains and Losses on Equity Securities	The components comprising total gains and losses in the period on equity securities are as follows: For the years ended December 31, 2020 2019 2018 Total gains (losses) recognized on equity securities $ 171 $ 301 $ (130) Gains (losses) recognized on equity securities sold (25) 100 (10) Unrealized gains (losses) recognized on equity securities held at end of period $ 196 $ 201 $ (120)
Notional Amount of Outstanding Derivative Positions	Following are the notional amounts of our outstanding derivative positions at December 31: 2020 2019 Interest rate swaps $ — $ 853 Cross-currency swaps 40,745 42,325 Interest rate locks — 3,500 Foreign exchange contracts 90 269 Total $ 40,835 $ 46,947
Effect on Derivatives on the Consolidated Statements of Income	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, 2020 2019 2018 Interest rate swaps (Interest expense): Gain (Loss) on interest rate swaps $ (6) $ 58 $ (12) Gain (Loss) on long-term debt 6 (58) 12 Cash Flow Hedging Relationships For the years ended December 31, 2020 2019 2018 Cross-currency swaps: Gain (Loss) recognized in accumulated OCI $ (378) $ (1,066) $ (825) Foreign exchange contracts: Gain (Loss) recognized in accumulated OCI 3 10 51 Other income (expense) - net reclassified from accumulated OCI into income (3) 6 39 Interest rate locks: Gain (Loss) recognized in accumulated OCI (648) (84) — Interest income (expense) reclassified from accumulated OCI into income (84) (63) (58)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components Of Deferred Tax Liabilities (Assets)	Significant components of our deferred tax liabilities (assets) are as follows at December 31: 2020 2019 Depreciation and amortization $ 46,952 $ 44,896 Licenses and nonamortizable intangibles 13,930 17,355 Employee benefits (5,279) (5,143) Deferred fulfillment costs 2,691 3,050 Net operating loss and other carryforwards (7,355) (7,301) Other – net 4,562 1,536 Subtotal 55,501 54,393 Deferred tax assets valuation allowance 4,773 4,941 Net deferred tax liabilities $ 60,274 $ 59,334 Noncurrent deferred tax liabilities $ 60,472 $ 59,502 Less: Noncurrent deferred tax assets (198) (168) Net deferred tax liabilities $ 60,274 $ 59,334
Changes in Unrecognized Tax Benefits Balance	A reconciliation of the change in our UTB balance from January 1 to December 31 for 2020 and 2019 is as follows: Federal, State and Foreign Tax 2020 2019 Balance at beginning of year $ 10,979 $ 10,358 Increases for tax positions related to the current year 1,580 903 Increases for tax positions related to prior years 112 1,106 Decreases for tax positions related to prior years (994) (1,283) Lapse of statute of limitations (24) (32) Settlements (1,646) (283) Current year acquisitions — 205 Foreign currency effects (6) 5 Balance at end of year 10,001 10,979 Accrued interest and penalties 2,450 2,708 Gross unrecognized income tax benefits 12,451 13,687 Less: Deferred federal and state income tax benefits (878) (886) Less: Tax attributable to timing items included above (3,588) (4,320) Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year $ 7,985 $ 8,481
Components of Income Tax Expense (Benefit)	The components of income tax (benefit) expense are as follows: 2020 2019 2018 Federal: Current $ (687) $ 584 $ 3,258 Deferred 1,039 1,656 277 352 2,240 3,535 State and local: Current (6) 603 513 Deferred 263 144 473 257 747 986 Foreign: Current 413 605 539 Deferred (57) (99) (140) 356 506 399 Total $ 965 $ 3,493 $ 4,920
Schedule of Income before Income Tax, Domestic and Foreign	“Income Before Income Taxes” in the Consolidated Statements of Income included the following components for the years ended December 31: 2020 2019 2018 U.S. income (loss) before income taxes $ (452) $ 18,301 $ 25,379 Foreign income (loss) before income taxes (2,404) 167 (506) Total $ (2,856) $ 18,468 $ 24,873
Reconciliation of Income Tax Expense (Benefit) Based on Federal Statutory Rate to Amount Per Effective Tax Rate	A reconciliation of income tax expense (benefit) and the amount computed by applying the statutory federal income tax rate of 21% to income from continuing operations before income taxes is as follows: 2020 2019 2018 Taxes computed at federal statutory rate $ (600) $ 3,878 $ 5,223 Increases (decreases) in income taxes resulting from: State and local income taxes - net of federal income tax benefit 193 611 738 Enactment date and measurement period adjustments from the Act — — (718) Tax on foreign investments (141) (115) (466) Noncontrolling interest (285) (230) (121) Permanent items and R&D credit (239) (285) (189) Audit resolutions (112) (156) 544 Divestitures 107 — — Goodwill impairment 1 2,120 — — Other - net (78) (210) (91) Total $ 965 $ 3,493 $ 4,920 Effective Tax Rate (33.8) % 18.9 % 19.8 % 1 Goodwill impairments are not deductible for tax purposes.

Pension And Postretirement Be_2

Pension And Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plan, Plan Assets, Description [Abstract]
Schedule of Plan Obligations in Excess of Plan Assets	The following table presents the change in the projected benefit obligation for the years ended December 31: Pension Benefits Postretirement Benefits 2020 2019 2020 2019 Benefit obligation at beginning of year $ 59,873 $ 55,439 $ 16,041 $ 19,378 Service cost - benefits earned during the period 1,029 1,019 53 71 Interest cost on projected benefit obligation 1,687 1,960 416 675 Amendments (340) — (2,655) (4,590) Actuarial (gain) loss 5,054 7,734 1,423 2,050 Special termination benefits — 81 — — Benefits paid (5,124) (6,356) (1,370) (1,543) Curtailment (1) — — — Plan transfers (20) (4) 20 — Benefit obligation at end of year $ 62,158 $ 59,873 $ 13,928 $ 16,041 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 2020 2019 2020 2019 Fair value of plan assets at beginning of year $ 53,530 $ 51,681 $ 4,145 $ 4,277 Actual return on plan assets 6,199 8,207 302 609 Benefits paid 1 (5,124) (6,356) (1,029) (941) Contributions 2 2 425 200 Plan transfers (1) (4) — — Fair value of plan assets at end of year 54,606 53,530 3,843 4,145 Unfunded status at end of year 2 $ (7,552) $ (6,343) $ (10,085) $ (11,896) 1 At our discretion, certain postretirement benefits may be paid from our 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 2020 2019 2020 2019 Current portion of employee benefit obligation 1 $ — $ — $ (1,213) $ (1,365) Employee benefit obligation 2 (7,552) (6,343) (8,872) (10,531) Net amount recognized $ (7,552) $ (6,343) $ (10,085) $ (11,896) 1 Included in “Accounts payable and accrued liabilities.” 2 Included in “Postemployment benefit obligation,” combined with international pension obligations and other postemployment obligations of $553 and $1,299 at December 31, 2020, respectively.
Schedule Of Defined Benefit Plan And Postretirement Benefits Disclosure	The following table presents the components of net periodic benefit cost (credit): Pension Benefits 1 Postretirement Benefits 2020 2019 2018 2020 2019 2018 Service cost – benefits earned during the period $ 1,029 $ 1,019 $ 1,116 $ 53 $ 71 $ 109 Interest cost on projected benefit obligation 1,687 1,960 2,092 416 675 778 Expected return on assets (3,557) (3,561) (3,190) (178) (227) (304) Amortization of prior service credit (113) (113) (115) (2,329) (1,820) (1,635) Actuarial (gain) loss 2,404 3,088 (812) 1,299 1,670 (2,290) Net pension and postretirement cost (credit) $ 1,450 $ 2,393 $ (909) $ (739) $ 369 $ (3,342) 1 Net periodic pension cost (credit) excludes immediate cost recognized due to special events: curtailment gain of ($1) in 2020 and special termination benefits of $81 in 2019. 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 2020 2019 2018 2020 2019 2018 Balance at beginning of year $ 361 $ 447 $ 571 $ 8,171 $ 6,086 $ 6,456 Prior service (cost) credit 250 — (37) 2,001 3,457 864 Amortization of prior service credit (86) (86) (87) (1,756) (1,372) (1,234) Total recognized in other comprehensive (income) loss 164 (86) (124) 245 2,085 (370) Balance at end of year $ 525 $ 361 $ 447 $ 8,416 $ 8,171 $ 6,086
Schedule of Assumptions in Determining the Projected Benefit Obligation and Net Pension and Postretirement Benefit Cost	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 2020 2019 2018 2020 2019 2018 Weighted-average discount rate for determining benefit obligation at December 31 2.70 % 3.40 % 4.50 % 2.40 % 3.20 % 4.40 % Discount rate in effect for determining service cost 1, 2 3.60 % 4.10 % 4.20 % 3.50 % 4.40 % 4.30 % Discount rate in effect for determining interest cost 1,2 2.90 % 3.50 % 3.80 % 2.70 % 3.70 % 3.60 % Weighted-average interest credit rate for cash balance pension programs 3 3.10 % 3.30 % 3.70 % — % — % — % Long-term rate of return on plan assets 7.00 % 7.00 % 7.00 % 4.75 % 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	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 2020 2019 Target 2020 2019 Equity securities: Domestic 16 % - 26 % 19 % 17 % 14 % - 24 % 19 % 20 % International 10 % - 20 % 15 12 9 % - 19 % 14 12 Fixed income securities 37 % - 47 % 35 35 40 % - 50 % 45 52 Real assets 8 % - 18 % 8 9 — % - 6 % 1 1 Private equity 5 % - 15 % 9 8 — % - 6 % 1 2 Preferred interest 6 % - 16 % 10 17 — % - — % — — Other — % - 5 % 4 2 15 % - 25 % 20 13 Total 100 % 100 % 100 % 100 %
Schedule of Fair Value of Pension and Postretirement Assets and Liabilities by Level	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, 2020: Pension Assets and Liabilities at Fair Value as of December 31, 2020 Level 1 Level 2 Level 3 Total Non-interest bearing cash $ 173 $ — $ — $ 173 Interest bearing cash 7 — — 7 Foreign currency contracts — 3 — 3 Equity securities: Domestic equities 9,784 — 11 9,795 International equities 4,821 11 12 4,844 Preferred interest — — 5,771 5,771 Fixed income securities: Corporate bonds and other investments — 11,043 52 11,095 Government and municipal bonds — 6,039 — 6,039 Mortgage-backed securities — 442 1 443 Real estate and real assets — — 2,544 2,544 Securities lending collateral 621 1,435 — 2,056 Receivable for variation margin 23 — — 23 Assets at fair value 15,429 18,973 8,391 42,793 Investments sold short and other liabilities at fair value (450) (8) (1) (459) Total plan net assets at fair value $ 14,979 $ 18,965 $ 8,390 $ 42,334 Assets held at net asset value practical expedient Private equity funds 5,154 Real estate funds 1,694 Commingled funds 7,706 Total assets held at net asset value practical expedient 14,554 Other assets (liabilities) 1 (2,282) Total Plan Net Assets $ 54,606 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, 2020 Level 1 Level 2 Level 3 Total Interest bearing cash $ 497 $ 302 $ — $ 799 Equity securities: Domestic equities 363 — — 363 International equities 282 — — 282 Fixed income securities: Corporate bonds and other investments 5 307 3 315 Government and municipal bonds 6 132 1 139 Mortgage-backed securities — 94 — 94 Securities lending collateral — 28 — 28 Assets at fair value 1,153 863 4 2,020 Securities lending payable and other liabilities (1) (29) — (30) Total plan net assets at fair value $ 1,152 $ 834 $ 4 $ 1,990 Assets held at net asset value practical expedient Commingled funds 1,843 Private equity 24 Real estate funds 22 Total assets held at net asset value practical expedient 1,889 Other assets (liabilities) 1 (36) Total Plan Net Assets $ 3,843 1 Other assets (liabilities) include amounts receivable and accounts payable. 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.
Summary of Changes in The Fair Value of the Level 3 Pension and Postretirement Assets	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, 2020: Pension Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ 8,816 $ 6 $ 2,817 $ 11,639 Realized gains (losses) (150) — 255 105 Unrealized gains (losses) 3 — (178) (175) Transfers in 4 51 36 91 Transfers out — (3) — (3) Purchases 9,114 1 223 9,338 Sales (11,994) (2) (609) (12,605) Balance at end of year $ 5,793 $ 53 $ 2,544 $ 8,390 Postretirement Assets Equities Fixed Income Funds Real Estate and Real Assets Total Balance at beginning of year $ — $ 32 $ — $ 32 Transfers in — 3 — 3 Transfers out — (11) — (11) Sales — (20) — (20) Balance at end of year $ — $ 4 $ — $ 4 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
Estimated Future Benefit Payments	The following table provides expected benefit payments under our pension and postretirement plans: Pension Benefits Postretirement Benefits 2021 $ 5,391 $ 1,392 2022 4,597 1,231 2023 4,428 1,159 2024 4,323 879 2025 4,234 832 Years 2026 - 2030 19,646 3,651

Share-Based Payments (Tables)

Share-Based Payments (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Compensation Cost	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: 2020 2019 2018 Performance stock units $ 348 $ 544 $ 301 Restricted stock and stock units 290 273 153 Other nonvested stock units — 7 4 Stock options — (5) 5 Total $ 638 $ 819 $ 463 Income tax benefit $ 157 $ 202 $ 114
Status of Nonvested Stock Units Activity and Changes During Year	A summary of the status of our nonvested stock units as of December 31, 2020, and changes during the year then ended is presented as follows (shares in millions): Nonvested Stock Units Shares Weighted-Average Grant- Nonvested at January 1, 2020 42 $ 33.80 Granted 23 36.90 Vested (18) 35.87 Forfeited (4) 34.48 Nonvested at December 31, 2020 43 $ 34.50

Sales Of Receivables (Tables)

Sales Of Receivables (Tables)	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Schedule of Finance Receivables	Our equipment installment and revolving receivables programs are discussed in detail below. The following table sets forth a summary of the receivables and accounts being serviced at December 31: 2020 2019 Equipment Installment Revolving Equipment Installment Revolving Gross receivables: $ 5,565 $ 3,909 $ 4,576 $ 3,324 Balance sheet classification Accounts receivable Notes receivable 2,716 — 2,467 — Trade receivables 554 3,715 477 2,809 Other Assets Noncurrent notes and trade receivables 2,295 194 1,632 515 Outstanding portfolio of receivables derecognized from our consolidated balance sheets 7,827 5,300 9,713 4,300 Cash proceeds received, net of remittances 1 5,646 5,300 7,211 4,300 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 under this program: 2020 2019 2018 Gross receivables sold $ 7,270 $ 9,921 $ 9,391 Net receivables sold 1 7,026 9,483 8,871 Cash proceeds received 6,089 8,189 7,488 Deferred purchase price recorded 1,021 1,451 1,578 Guarantee obligation recorded 157 341 361 1 Receivables net of allowance, imputed interest and equipment trade-in right guarantees. 2020 2019 2018 Fair value of repurchased receivables $ 1,271 $ 1,418 $ 1,480 Carrying value of deferred purchase price 1,235 1,350 1,393 Gain on repurchases 1 $ 36 $ 68 $ 87 1 These gains are included in “Selling, general and administrative” in the consolidated statements of income.
Schedule of Receivables Sold	The following table sets forth a summary of receivables sold: 2020 2019 2018 Gross receivables sold/cash proceeds received 1 $ 15,888 $ 11,989 $ — Collections reinvested under revolving agreement 14,888 7,689 — Net cash proceeds received (remitted) $ 1,000 $ 4,300 $ — Net receivables sold 2 $ 15,760 $ 11,604 $ — Obligations recorded (reversed) 271 530 — 1 Includes initial sale of receivables of $1,000 and $4,300 for 2020 and 2019, respectively. 2 Receivables net of allowance, return and incentive reserves and imputed interest.

Additional Financial Informat_2

Additional Financial Information (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidated Balance Sheets	December 31, Consolidated Balance Sheets 2020 2019 Accounts payable and accrued liabilities: Accounts payable $ 31,836 $ 29,640 Accrued payroll and commissions 2,988 3,126 Current portion of employee benefit obligation 1,415 1,528 Accrued participations and residuals 2,708 2,852 Accrued interest 2,454 2,498 Other 7,631 6,312 Total accounts payable and accrued liabilities $ 49,032 $ 45,956
Consolidated Statements of Income	Consolidated Statements of Income 2020 2019 2018 Advertising expense $ 5,253 $ 6,121 $ 5,100 Interest expense incurred $ 8,048 $ 8,622 $ 8,450 Capitalized interest (123) (200) (493) Total interest expense $ 7,925 $ 8,422 $ 7,957
Consolidated Statements of Cash Flows	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 2020 2019 2018 2017 Cash and cash equivalents $ 9,740 $ 12,130 $ 5,204 $ 50,498 Restricted cash in Other current assets 9 69 61 6 Restricted cash in Other Assets 121 96 135 428 Cash and cash equivalents and restricted cash $ 9,870 $ 12,295 $ 5,400 $ 50,932 The following table summarizes cash paid during the periods for interest and income taxes: Consolidated Statements of Cash Flows 2020 2019 2018 Cash paid (received) during the year for: Interest $ 8,237 $ 8,693 $ 8,818 Income taxes, net of refunds 993 1,421 (354) Spectrum acquisitions 1,613 1,576 521

Summary Of Significant Accoun_3

Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 01, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 37,457	$ 57,936
Contract asset		3,501	2,472
Deferred income tax liability		60,472	59,502
Noncontrolling interest		17,567	17,713
Operating lease liability		25,739	25,255
Operating lease right-of-use assets		24,714	24,039
Other current assets		(20,231)	(18,364)
Cash		2,842
Cash and cash equivalents		9,740	12,130	$ 5,204			$ 50,498
Equipment inventories		$ 3,592	2,864
Estimated period of ultimate revenues, from initial release or from delivery of first episode (years)		10 years
FCC licenses - typical term (in years)		10 years
Estimated economic useful life		22 years 3 months 18 days
Amortization expense		$ 8,239	$ 7,932	$ 8,347
Diluted earnings per share attributable to Common Stock (in dollars per share)		$ (0.75)	$ 1.89	$ 2.85
Wireless licenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated economic useful life		24 years 7 months 6 days
Orbital slots
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated economic useful life		15 years
Money Market Funds and Other Cash Equivalents
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash equivalents		$ 6,898
Foreign Jurisdictions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and cash equivalents		$ 2,205
Minimum | Software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization period for capitalized software costs		3 years
Maximum | Software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization period for capitalized software costs		7 years
Mexico | Wireless licenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated economic useful life		25 years
Communications | Orbital slots | Intangible Assets, Amortization Period
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated economic useful life	15 years
Amortization expense		$ 1,504
Diluted earnings per share attributable to Common Stock (in dollars per share)		$ 0.16
Latin America | Trade names | Intangible Assets, Amortization Period
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated economic useful life		15 years
ASU 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ (293)
Allowance for credit loss	395
Contract asset	(10)
Deferred income tax liability	(105)
Noncontrolling interest	$ (7)
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					$ 316
Operating lease liability					22,121
Operating lease right-of-use assets					22,121
Net Assets					20,960
ASU 2019-02 | Programming Inventory Costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets					2,274
Other assets					$ 2,274
ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings						$ 2,342
Contract asset						1,737
Deferred income tax liability						787
Noncontrolling interest						35
Other assets						(239)
Deferred contract acquisition costs						1,454
Other liabilities						(212)
ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings						$ 658

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator for basic earnings per share:
Net Income (Loss)	$ (3,821)	$ 14,975	$ 19,953
Less: Net Income Attributable to Noncontrolling Interest	(1,355)	(1,072)	(583)
Net Income (Loss) Attributable to AT&T	(5,176)	13,903	19,370
Less: Preferred Stock Dividends	(193)	(3)	0
Net Income (Loss) Attributable to Common Stock	(5,369)	13,900	19,370
Dilutive potential common shares:
Share-based payment 1	23	21	19
Numerator for diluted earnings per share	$ (5,346)	$ 13,921	$ 19,389
Denominator for basic earnings per share:
Weighted-average number of common shares outstanding (in shares)	7,157	7,319	6,778
Dilutive potential common shares:
Share-based payment (in shares)	26	29	28
Denominator for diluted earnings per share (in shares)	7,183	7,348	6,806
Basic Earnings Per Share Attributable to Common Stock (in dollars per share)	$ (0.75)	$ 1.90	$ 2.85
Diluted Earnings Per Share Attributable to Common Stock (in dollars per share)	$ (0.75)	$ 1.89	$ 2.85

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Repurchase of common stock		$ 5,498	$ 2,417	$ 609
Repurchase of common stock (in shares)		142
Stock Repurchase Program
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Repurchase of common stock	$ 4,000
Repurchase of common stock (in shares)	104.8

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications	$ 647	$ 2,635	$ (801)
Amounts reclassified from accumulated OCI	(1,787)	(1,414)	(1,309)
Other comprehensive income (loss) attributable to AT&T	(1,140)	1,221	(2,110)
Accumulated Other Comprehensive Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	5,470	4,249	7,017
Other comprehensive income (loss) attributable to AT&T	(1,140)	1,221	(2,110)
Accumulated other comprehensive income, ending balance	4,330	5,470	4,249
Accumulated Other Comprehensive Income | Amounts reclassified to retained earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			(658)
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	(3,056)	(3,084)	(2,054)
Other comprehensive income (loss) before reclassifications	(870)	28	(1,030)
Amounts reclassified from accumulated OCI	0	0	0
Other comprehensive income (loss) attributable to AT&T	(870)	28	(1,030)
Accumulated other comprehensive income, ending balance	(3,926)	(3,056)	(3,084)
Foreign Currency Translation Adjustment | Amounts reclassified to retained earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			0
Net Unrealized Gains (Losses) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	48	(2)	660
Other comprehensive income (loss) before reclassifications	78	50	(4)
Amounts reclassified from accumulated OCI	(15)	0	0
Other comprehensive income (loss) attributable to AT&T	63	50	(4)
Accumulated other comprehensive income, ending balance	111	48	(2)
Net Unrealized Gains (Losses) on Available-for-Sale Securities | Amounts reclassified to retained earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			(658)
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			1,402
Other comprehensive income (loss) before reclassifications			(597)
Amounts reclassified from accumulated OCI			13
Other comprehensive income (loss) attributable to AT&T			(584)
Net Unrealized Gains (Losses) on Cash Flow Hedges | Amounts reclassified to retained earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			0
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	(37)	818
Other comprehensive income (loss) before reclassifications	(811)	(900)
Amounts reclassified from accumulated OCI	69	45
Other comprehensive income (loss) attributable to AT&T	(742)	(855)
Accumulated other comprehensive income, ending balance	(779)	(37)	818
Defined Benefit Postretirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance	8,515	6,517	7,009
Other comprehensive income (loss) before reclassifications	2,250	3,457	830
Amounts reclassified from accumulated OCI	(1,841)	(1,459)	(1,322)
Other comprehensive income (loss) attributable to AT&T	409	1,998	(492)
Accumulated other comprehensive income, ending balance	$ 8,924	$ 8,515	6,517
Defined Benefit Postretirement Plans | Amounts reclassified to retained earnings
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			$ 0

Segment Information (Summary Of

Segment Information (Summary Of Operating Revenues And Expenses By Segment) (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information (Summary _2

Segment Information (Summary Of Operating Revenues And Expenses By Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 171,760	$ 181,193	$ 170,756
Operations and Support Expenses	136,839	125,021	116,230
EBITDA	34,921	56,172	54,526
Depreciation and Amortization	28,516	28,217	28,430
Operating Income (Loss)	6,405	27,955	26,096
Equity in Net Income (Loss) of Affiliates	95	6	(48)
Income (Loss) Before Income Taxes	(2,856)	18,468	24,873
Reclassification of prior service credit amortization	2,442	1,934	1,753
Operating Segments
Segment Reporting Information [Line Items]
Revenues	146,123	152,191	138,360
Operations and Support Expenses	92,451	94,930	84,735
EBITDA	53,672	57,261	53,625
Depreciation and Amortization	17,920	17,610	17,139
Operating Income (Loss)	35,752	39,651	36,486
Equity in Net Income (Loss) of Affiliates	42	188	59
Income (Loss) Before Income Taxes	35,794	39,839	36,545
Corporate
Segment Reporting Information [Line Items]
Revenues	2,207	2,203	2,481
Operations and Support Expenses	4,205	3,509	2,502
EBITDA	(1,998)	(1,306)	(21)
Depreciation and Amortization	310	645	1,637
Operating Income (Loss)	(2,308)	(1,951)	(1,658)
Reconciling Items
Segment Reporting Information [Line Items]
Equity in Net Income (Loss) of Affiliates	(42)	(188)	(59)
Video
Segment Reporting Information [Line Items]
Revenues	28,610	32,124	33,363
Operations and Support Expenses	24,174	27,275	28,856
EBITDA	4,436	4,849	4,507
Depreciation and Amortization	2,262	2,461	2,698
Operating Income (Loss)	2,174	2,388	1,809
Acquisition-related items
Segment Reporting Information [Line Items]
Revenues	0	(72)	(49)
Operations and Support Expenses	468	960	1,185
EBITDA	(468)	(1,032)	(1,234)
Depreciation and Amortization	8,012	7,460	6,931
Operating Income (Loss)	(8,480)	(8,492)	(8,165)
Certain significant items
Segment Reporting Information [Line Items]
Revenues	0	0	0
Operations and Support Expenses	19,156	2,082	899
EBITDA	(19,156)	(2,082)	(899)
Depreciation and Amortization	14	43	26
Operating Income (Loss)	(19,170)	(2,125)	(925)
Eliminations and consolidations
Segment Reporting Information [Line Items]
Revenues	(5,180)	(5,253)	(3,399)
Operations and Support Expenses	(3,615)	(3,735)	(1,947)
EBITDA	(1,565)	(1,518)	(1,452)
Depreciation and Amortization	(2)	(2)	(1)
Operating Income (Loss)	(1,563)	(1,516)	(1,451)
Communications | Operating Segments
Segment Reporting Information [Line Items]
Revenues	109,965	109,969	110,123
Operations and Support Expenses	65,436	64,295	64,298
EBITDA	44,529	45,674	45,825
Depreciation and Amortization	16,216	15,859	15,590
Operating Income (Loss)	28,313	29,815	30,235
Equity in Net Income (Loss) of Affiliates	0	0	0
Income (Loss) Before Income Taxes	28,313	29,815	30,235
Communications | Mobility | Operating Segments
Segment Reporting Information [Line Items]
Revenues	72,564	71,056	70,521
Operations and Support Expenses	42,106	40,681	40,690
EBITDA	30,458	30,375	29,831
Depreciation and Amortization	8,086	8,054	8,263
Operating Income (Loss)	22,372	22,321	21,568
Equity in Net Income (Loss) of Affiliates	0	0	0
Income (Loss) Before Income Taxes	22,372	22,321	21,568
Communications | Business Wireline | Operating Segments
Segment Reporting Information [Line Items]
Revenues	25,083	25,901	26,494
Operations and Support Expenses	15,303	15,839	16,012
EBITDA	9,780	10,062	10,482
Depreciation and Amortization	5,216	4,925	4,704
Operating Income (Loss)	4,564	5,137	5,778
Equity in Net Income (Loss) of Affiliates	0	0	0
Income (Loss) Before Income Taxes	4,564	5,137	5,778
Communications | Consumer Wireline | Operating Segments
Segment Reporting Information [Line Items]
Revenues	12,318	13,012	13,108
Operations and Support Expenses	8,027	7,775	7,596
EBITDA	4,291	5,237	5,512
Depreciation and Amortization	2,914	2,880	2,623
Operating Income (Loss)	1,377	2,357	2,889
Equity in Net Income (Loss) of Affiliates	0	0	0
Income (Loss) Before Income Taxes	1,377	2,357	2,889
WarnerMedia | Operating Segments
Segment Reporting Information [Line Items]
Revenues	30,442	35,259	20,585
Operations and Support Expenses	21,579	24,172	13,279
EBITDA	8,863	11,087	7,306
Depreciation and Amortization	671	589	311
Operating Income (Loss)	8,192	10,498	6,995
Equity in Net Income (Loss) of Affiliates	18	161	25
Income (Loss) Before Income Taxes	8,210	10,659	7,020
WarnerMedia | Eliminations and other
Segment Reporting Information [Line Items]
Revenues	(1,088)	1,030	1,305
Operations and Support Expenses	(1,320)	304	168
EBITDA	232	726	1,137
Depreciation and Amortization	127	90	28
Operating Income (Loss)	105	636	1,109
Equity in Net Income (Loss) of Affiliates	74	109	(30)
Income (Loss) Before Income Taxes	179	745	1,079
WarnerMedia | Turner | Operating Segments
Segment Reporting Information [Line Items]
Revenues	12,568	13,122	6,979
Operations and Support Expenses	6,954	7,740	3,794
EBITDA	5,614	5,382	3,185
Depreciation and Amortization	277	235	131
Operating Income (Loss)	5,337	5,147	3,054
Equity in Net Income (Loss) of Affiliates	(2)	52	54
Income (Loss) Before Income Taxes	5,335	5,199	3,108
WarnerMedia | Home Box Office | Operating Segments
Segment Reporting Information [Line Items]
Revenues	6,808	6,749	3,598
Operations and Support Expenses	6,028	4,312	2,187
EBITDA	780	2,437	1,411
Depreciation and Amortization	98	102	56
Operating Income (Loss)	682	2,335	1,355
Equity in Net Income (Loss) of Affiliates	16	30	29
Income (Loss) Before Income Taxes	698	2,365	1,384
WarnerMedia | Warner Bros. | Operating Segments
Segment Reporting Information [Line Items]
Revenues	12,154	14,358	8,703
Operations and Support Expenses	9,917	11,816	7,130
EBITDA	2,237	2,542	1,573
Depreciation and Amortization	169	162	96
Operating Income (Loss)	2,068	2,380	1,477
Equity in Net Income (Loss) of Affiliates	(70)	(30)	(28)
Income (Loss) Before Income Taxes	1,998	2,350	1,449
Latin America | Operating Segments
Segment Reporting Information [Line Items]
Revenues	5,716	6,963	7,652
Operations and Support Expenses	5,436	6,463	7,158
EBITDA	280	500	494
Depreciation and Amortization	1,033	1,162	1,238
Operating Income (Loss)	(753)	(662)	(744)
Equity in Net Income (Loss) of Affiliates	24	27	34
Income (Loss) Before Income Taxes	(729)	(635)	(710)
Latin America | Vrio | Operating Segments
Segment Reporting Information [Line Items]
Revenues	3,154	4,094	4,784
Operations and Support Expenses	2,800	3,378	3,743
EBITDA	354	716	1,041
Depreciation and Amortization	520	660	728
Operating Income (Loss)	(166)	56	313
Equity in Net Income (Loss) of Affiliates	24	27	34
Income (Loss) Before Income Taxes	(142)	83	347
Latin America | Mexico | Operating Segments
Segment Reporting Information [Line Items]
Revenues	2,562	2,869	2,868
Operations and Support Expenses	2,636	3,085	3,415
EBITDA	(74)	(216)	(547)
Depreciation and Amortization	513	502	510
Operating Income (Loss)	(587)	(718)	(1,057)
Equity in Net Income (Loss) of Affiliates	0	0	0
Income (Loss) Before Income Taxes	$ (587)	$ (718)	$ (1,057)

Segment Information (Reconcilia

Segment Information (Reconciliation Of Operating Income (Loss) to Consolidated Statement Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) Before Income Taxes	$ (2,856)	$ 18,468	$ 24,873
AT&T Operating Income	6,405	27,955	26,096
Amortization of intangibles acquired	(8,239)	(7,932)	(8,347)
Impairments and abandonments	(18,880)	(1,458)	(46)
Equity in net income (loss) of affiliates	95	6	(48)
Interest Expense	7,925	8,422	7,957
Other income (expense) - net	(1,431)	(1,071)	6,782
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) Before Income Taxes	35,794	39,839	36,545
AT&T Operating Income	35,752	39,651	36,486
Equity in net income (loss) of affiliates	42	188	59
Operating Segments | Communications
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) Before Income Taxes	28,313	29,815	30,235
AT&T Operating Income	28,313	29,815	30,235
Equity in net income (loss) of affiliates	0	0	0
Operating Segments | WarnerMedia
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) Before Income Taxes	8,210	10,659	7,020
AT&T Operating Income	8,192	10,498	6,995
Equity in net income (loss) of affiliates	18	161	25
Operating Segments | Latin America
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) Before Income Taxes	(729)	(635)	(710)
AT&T Operating Income	(753)	(662)	(744)
Equity in net income (loss) of affiliates	24	27	34
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	(2,308)	(1,951)	(1,658)
Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Merger and integration items	(468)	(1,032)	(1,234)
Amortization of intangibles acquired	(8,012)	(7,460)	(6,931)
Impairments and abandonments	(18,880)	(1,458)	(46)
Gain on spectrum transaction	900	0	0
Employee separation charges and benefit-related (gain) loss	(1,177)	(624)	(587)
Other noncash charges (credits), net	(13)	(43)	(111)
Natural disaster items	0	0	(181)
Equity in net income (loss) of affiliates	(42)	(188)	(59)
Video
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	2,174	2,388	1,809
Eliminations and consolidations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
AT&T Operating Income	$ (1,563)	$ (1,516)	$ (1,451)

Segment Information (Schedule o

Segment Information (Schedule of Schedule of Revenues Earned from Customers and Property, Plant and Equipment by Geographical Areas) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 171,760	$ 181,193	$ 170,756
Net Property, Plant & Equipment	127,315	130,128	131,473
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	155,899	161,689	154,795
Net Property, Plant & Equipment	121,208	122,567	123,457
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	5,387	6,536	4,073
Net Property, Plant & Equipment	1,152	1,854	1,634
Mexico
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,862	3,198	3,100
Net Property, Plant & Equipment	3,530	3,648	3,467
Brazil
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	1,807	2,797	2,724
Net Property, Plant & Equipment	694	1,057	1,213
All other Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,679	3,219	3,055
Net Property, Plant & Equipment	485	544	1,217
Asia/Pacific Rim
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,322	2,793	2,214
Net Property, Plant & Equipment	203	390	408
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	804	961	795
Net Property, Plant & Equipment	$ 43	$ 68	$ 77

Segment Information (Intersegme

Segment Information (Intersegment Details) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total revenues	$ (171,760)	$ (181,193)	$ (170,756)
Total Intersegment Revenues
Segment Reporting Information [Line Items]
Total revenues	3,194	3,344	1,888
Consolidations
Segment Reporting Information [Line Items]
Total revenues	1,986	1,909	1,511
Eliminations and consolidations
Segment Reporting Information [Line Items]
Total revenues	5,180	5,253	3,399
Communications | Total Intersegment Revenues
Segment Reporting Information [Line Items]
Total revenues	11	26	13
WarnerMedia | Total Intersegment Revenues
Segment Reporting Information [Line Items]
Total revenues	3,183	3,318	1,875
Latin America | Total Intersegment Revenues
Segment Reporting Information [Line Items]
Total revenues	$ 0	$ 0	$ 0

Segment Information (Interseg_2

Segment Information (Intersegment Assets, Equity Affiliates Investments and Capital Expenditures Details) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Assets	$ 525,761	$ 551,669
Investments in Equity Method Investees	1,780	3,695	$ 6,245
Capital Expenditures	15,675	19,635	$ 21,251
Corporate and eliminations1
Segment Reporting Information [Line Items]
Assets	(144,189)	(101,962)
Investments in Equity Method Investees	67	34
Capital Expenditures	161	263
Communications | Operating Segments
Segment Reporting Information [Line Items]
Assets	506,102	492,649
Investments in Equity Method Investees	0	0
Capital Expenditures	14,107	17,410
WarnerMedia | Operating Segments
Segment Reporting Information [Line Items]
Assets	148,037	140,376
Investments in Equity Method Investees	1,123	3,011
Capital Expenditures	699	1,205
Latin America | Operating Segments
Segment Reporting Information [Line Items]
Assets	15,811	20,606
Investments in Equity Method Investees	590	650
Capital Expenditures	$ 708	$ 757

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Content revenue, commencement period	3 years
Contract with Customer, Asset and Liability [Abstract]
Beginning of period contract liability recorded as customer contract revenue during period	$ 5,579
Contract asset balance - current portion	2,054	$ 1,611
Contract liability balance - current portion	6,071	$ 5,939
Revenue, Performance Obligation [Abstract]
Aggregate amount of the transaction price allocated to remaining performance obligations	$ 42,072
Deferred Acquisition Costs | Minimum
Capitalized Contract Cost [Line Items]
Expected customer relationship life	3 years
Deferred Acquisition Costs | Maximum
Capitalized Contract Cost [Line Items]
Expected customer relationship life	5 years
Deferred Fulfillment Costs | Minimum
Capitalized Contract Cost [Line Items]
Expected customer relationship life	3 years
Deferred Fulfillment Costs | Maximum
Capitalized Contract Cost [Line Items]
Expected customer relationship life	5 years

Revenue Recognition (Revenue Ca

Revenue Recognition (Revenue Categories) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 171,760	$ 181,193	$ 170,756
Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	57,435	57,530	56,482
Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	24,634	25,441	26,066
Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	8,534	8,403	7,956
Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	2,767	3,138	3,330
Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	40,556	44,947	42,170
Content
Disaggregation of Revenue [Line Items]
Total operating revenues	9,819	13,880	8,384
Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	6,416	6,970	4,422
Other
Disaggregation of Revenue [Line Items]
Total operating revenues	2,606	3,190	3,535
Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	18,993	17,694	18,411
Operating Segments
Disaggregation of Revenue [Line Items]
Total operating revenues	146,123	152,191	138,360
Operating Segments | Communications
Disaggregation of Revenue [Line Items]
Total operating revenues	109,965	109,969	110,123
Operating Segments | Communications | Mobility
Disaggregation of Revenue [Line Items]
Total operating revenues	72,564	71,056	70,521
Operating Segments | Communications | Mobility | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	55,251	55,039	54,063
Operating Segments | Communications | Mobility | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	291	292	232
Operating Segments | Communications | Mobility | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Mobility | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	17,022	15,725	16,226
Operating Segments | Communications | Video | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues		0
Operating Segments | Communications | Video | Content
Disaggregation of Revenue [Line Items]
Total operating revenues		0
Operating Segments | Communications | Business Wireline
Disaggregation of Revenue [Line Items]
Total operating revenues	25,083	25,901	26,494
Operating Segments | Communications | Business Wireline | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	24,313	25,116	25,671
Operating Segments | Communications | Business Wireline | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Business Wireline | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	770	785	823
Operating Segments | Communications | Consumer Wireline
Disaggregation of Revenue [Line Items]
Total operating revenues	12,318	13,012	13,108
Operating Segments | Communications | Consumer Wireline | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	8,534	8,403	7,956
Operating Segments | Communications | Consumer Wireline | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	2,213	2,573	3,042
Operating Segments | Communications | Consumer Wireline | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Communications | Consumer Wireline | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	1,564	2,029	2,101
Operating Segments | Communications | Consumer Wireline | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	7	7	9
Operating Segments | WarnerMedia
Disaggregation of Revenue [Line Items]
Total operating revenues	30,442	35,259	20,585
Operating Segments | WarnerMedia | Turner
Disaggregation of Revenue [Line Items]
Total operating revenues	12,568	13,122	6,979
Operating Segments | WarnerMedia | Turner | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Turner | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Turner | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Turner | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Turner | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	7,613	7,736	4,207
Operating Segments | WarnerMedia | Turner | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	759	481	295
Operating Segments | WarnerMedia | Turner | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	3,941	4,566	2,330
Operating Segments | WarnerMedia | Turner | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	255	339	147
Operating Segments | WarnerMedia | Turner | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Home Box Office
Disaggregation of Revenue [Line Items]
Total operating revenues	6,808	6,749	3,598
Operating Segments | WarnerMedia | Home Box Office | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Home Box Office | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Home Box Office | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Home Box Office | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Home Box Office | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	6,090	5,814	3,201
Operating Segments | WarnerMedia | Home Box Office | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	692	925	391
Operating Segments | WarnerMedia | Home Box Office | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Home Box Office | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	26	10	6
Operating Segments | WarnerMedia | Home Box Office | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Warner Bros.
Disaggregation of Revenue [Line Items]
Total operating revenues	12,154	14,358	8,703
Operating Segments | WarnerMedia | Warner Bros. | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Warner Bros. | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Warner Bros. | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Warner Bros. | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | WarnerMedia | Warner Bros. | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	50	88	47
Operating Segments | WarnerMedia | Warner Bros. | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	11,632	13,532	8,216
Operating Segments | WarnerMedia | Warner Bros. | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	6	41	53
Operating Segments | WarnerMedia | Warner Bros. | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	466	697	387
Operating Segments | WarnerMedia | Warner Bros. | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America
Disaggregation of Revenue [Line Items]
Total operating revenues	5,716	6,963	7,652
Operating Segments | Latin America | Vrio
Disaggregation of Revenue [Line Items]
Total operating revenues	3,154	4,094	4,784
Operating Segments | Latin America | Vrio | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	3,154	4,094	4,784
Operating Segments | Latin America | Vrio | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Vrio | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico
Disaggregation of Revenue [Line Items]
Total operating revenues	2,562	2,869	2,868
Operating Segments | Latin America | Mexico | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	1,656	1,863	1,701
Operating Segments | Latin America | Mexico | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Operating Segments | Latin America | Mexico | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	906	1,006	1,167
Eliminations and other | WarnerMedia
Disaggregation of Revenue [Line Items]
Total operating revenues	(1,088)	1,030	1,305
Eliminations and other | WarnerMedia | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and other | WarnerMedia | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and other | WarnerMedia | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and other | WarnerMedia | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and other | WarnerMedia | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	12	13	6
Eliminations and other | WarnerMedia | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	(3,264)	(1,058)	(518)
Eliminations and other | WarnerMedia | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	2,178	2,071	1,807
Eliminations and other | WarnerMedia | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	(14)	4	10
Eliminations and other | WarnerMedia | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and other | WarnerMedia | Warner Bros. | Content sales with HBO Max
Disaggregation of Revenue [Line Items]
Total operating revenues	2,250
Eliminations and other | WarnerMedia | Warner Bros. | Content sales with HBO Linear
Disaggregation of Revenue [Line Items]
Total operating revenues	600	500	225
Eliminations and other | WarnerMedia | Warner Bros. | Content sales with Turner
Disaggregation of Revenue [Line Items]
Total operating revenues	300	350	225
Corporate and Other
Disaggregation of Revenue [Line Items]
Total operating revenues	30,817	34,255	35,795
Corporate and Other | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	528	628	718
Corporate and Other | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	321	325	395
Corporate and Other | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Corporate and Other | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	554	565	288
Corporate and Other | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	26,747	30,451	31,768
Corporate and Other | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Corporate and Other | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	1,718	1,672	1,595
Corporate and Other | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	661	443	845
Corporate and Other | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	288	171	186
Eliminations and consolidations
Disaggregation of Revenue [Line Items]
Total operating revenues	(5,180)	(5,253)	(3,399)
Eliminations and consolidations | Wireless
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and consolidations | Business Service [Member]
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and consolidations | Advanced Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and consolidations | Legacy Voice & Data
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and consolidations | Subscription
Disaggregation of Revenue [Line Items]
Total operating revenues	(3,110)	(3,249)	(1,843)
Eliminations and consolidations | Content
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and consolidations | Advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	(1,718)	(1,672)	(1,595)
Eliminations and consolidations | Other
Disaggregation of Revenue [Line Items]
Total operating revenues	(352)	(332)	39
Eliminations and consolidations | Equipment
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0
Eliminations and consolidations | Video | Turner channel distribution arrangements with Entertainment Group
Disaggregation of Revenue [Line Items]
Total operating revenues	1,500	1,740	1,000
Eliminations and consolidations | Video | HBO linear channel distribution arrangements with Entertainment Group
Disaggregation of Revenue [Line Items]
Total operating revenues	950	$ 1,320	$ 700
Eliminations and consolidations | Video | HBO customer subscriptions at Mobility
Disaggregation of Revenue [Line Items]
Total operating revenues	290
Eliminations and consolidations | Consumer Wireline | HBO customer subscriptions at Mobility
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 180

Revenue Recognition (Deferred C

Revenue Recognition (Deferred Contract Acquisition and Fulfillment Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Deferred Acquisition Costs
Capitalized Contract Cost, Net [Abstract]
Total deferred costs	$ 6,285	$ 5,453
Deferred cost amortization	2,755	2,174
Deferred Acquisition Costs | Other current assets
Capitalized Contract Cost, Net [Abstract]
Total deferred costs	3,087	2,462
Deferred Acquisition Costs | Other Assets
Capitalized Contract Cost, Net [Abstract]
Total deferred costs	3,198	2,991
Deferred Fulfillment Costs
Capitalized Contract Cost, Net [Abstract]
Total deferred costs	9,752	10,958
Deferred cost amortization	5,110	4,947
Deferred Fulfillment Costs | Other current assets
Capitalized Contract Cost, Net [Abstract]
Total deferred costs	4,118	4,519
Deferred Fulfillment Costs | Other Assets
Capitalized Contract Cost, Net [Abstract]
Total deferred costs	$ 5,634	$ 6,439

Revenue Recognition (Contract A

Revenue Recognition (Contract Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Asset and Liability [Abstract]
Contract assets	$ 3,501	$ 2,472
Contract liabilities	$ 6,879	$ 6,999

Revenue Recognition (Remaining

Revenue Recognition (Remaining Performance Obligations) (Details)	Dec. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Aggregate amount of the transaction price allocated to remaining performance obligations (percentage)	60.00%
Expected timing of satisfaction for remaining performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Aggregate amount of the transaction price allocated to remaining performance obligations (percentage)	40.00%
Expected timing of satisfaction for remaining performance obligations, period

Acquisitions, Dispositions An_3

Acquisitions, Dispositions And Other Adjustments (HBO LAG, Time Warner, Otter and AppNexus Acquisitions Narrative) (Details) - USD ($) $ in Millions	Aug. 15, 2018	Aug. 07, 2018	May 31, 2020	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Acquisitions, net of cash acquired						$ 1,851	$ 1,809	$ 43,309
Goodwill					$ 146,370	135,259	146,241	146,370
Revenues						171,760	181,193	170,756
Operating income						6,405	27,955	26,096
Intangible amortization						8,239	7,932	8,347
Conversion to equity of advance made in first quarter of 2018						160	365	1,050
WarnerMedia
Business Acquisition [Line Items]
Goodwill					42,101	$ 42,447	$ 42,345	$ 42,101
HBO LAG | WarnerMedia
Business Acquisition [Line Items]
Acquisitions, net of cash acquired			$ 141
Pre-tax remeasurement gain			68
Acquisition of intangible assets, trade names			640
Goodwill			346
HBO LAG | WarnerMedia | Distribution Networks – Net
Business Acquisition [Line Items]
Acquisition of other intangible assets			$ 271
Time Warner
Business Acquisition [Line Items]
Total consideration				$ 79,358
Time Warner | Acquisition
Business Acquisition [Line Items]
Revenues					18,209
Operating income					1,400
Intangible amortization					$ 3,296
Otter Media | WarnerMedia
Business Acquisition [Line Items]
Acquisitions, net of cash acquired		$ 157
Pre-tax remeasurement gain		395
Goodwill		1,239
Conversion to equity of advance made in first quarter of 2018		$ 1,480
AppNexus | WarnerMedia
Business Acquisition [Line Items]
Goodwill	$ 1,220
Total consideration	$ 1,432

Acquisitions, Dispositions An_4

Acquisitions, Dispositions And Other Adjustments (Pro-Forma Consolidated Results Of Operations) (Details) - Time Warner - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [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 Common Stock (in dollars per share)	$ 2.86	$ 4.30
Diluted Earnings Per Share Attributable to Common Stock (in dollars per share)	$ 2.85	$ 4.26

Acquisitions, Dispositions An_5

Acquisitions, Dispositions And Other Adjustments (Spectrum Auctions Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020
Licensing Agreements
Indefinite-lived Intangible Assets [Line Items]
Payments to acquire intangible assets	$ 2,379		$ 949		$ 1,186
24 GHz Licenses
Indefinite-lived Intangible Assets [Line Items]
Payments to acquire intangible assets		$ 982
FiberTower Corporation | 39 GHz Licenses
Indefinite-lived Intangible Assets [Line Items]
Book value of indefinite-lived intangible assets				$ 300
Gain on disposition of intangible asset				$ 900
Value of consideration received in a noncash transaction					$ 1,200

Acquisitions, Dispositions An_6

Acquisitions, Dispositions And Other Adjustments (Dispositions Narrative) (Details) - USD ($) $ in Millions	Nov. 06, 2020	Oct. 31, 2020	Oct. 13, 2020	Dec. 31, 2018	Jun. 30, 2019	Apr. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Cash proceeds from sale of businesses and interest in affiliates							$ 3,641	$ 4,684	$ 2,148
Debt guarantee, original amount covered			$ 1,100
Debt guarantee			$ 600
Payments to redeem cumulative preferred interest in subsidiary that held notes secured by proceeds of sale							$ 1,950	$ 0	0
CME
Business Acquisition [Line Items]
Percent of interest disposed			65.30%
Cash proceeds from sale of businesses and interest in affiliates			$ 1,100
Gain (loss) on sale of investment			$ 39
Discontinued Operations, Disposed of by Sale | Puerto Rico And U.S. Virgin Islands Operations
Business Acquisition [Line Items]
Gain (loss) on sale of investment		$ (82)
Consideration for completion of sale of operations		1,950
Payments to redeem cumulative preferred interest in subsidiary that held notes secured by proceeds of sale	$ 1,950	1,950
Discontinued Operations, Disposed of by Sale | Puerto Rico And U.S. Virgin Islands Operations | Net Tax Liabilities
Business Acquisition [Line Items]
Decrease in accounts payable and accrued liabilities due to removal of held-for-sale liabilities upon disposal		500
Discontinued Operations, Disposed of by Sale | Puerto Rico And U.S. Virgin Islands Operations | FCC Licenses
Business Acquisition [Line Items]
Decrease in other current assets due to removal of held-for-sale assets upon disposal		1,100
Discontinued Operations, Disposed of by Sale | Puerto Rico And U.S. Virgin Islands Operations | Goodwill
Business Acquisition [Line Items]
Decrease in other current assets due to removal of held-for-sale assets upon disposal		250
Discontinued Operations, Disposed of by Sale | Puerto Rico And U.S. Virgin Islands Operations | Property, Plant and Equipment
Business Acquisition [Line Items]
Decrease in other current assets due to removal of held-for-sale assets upon disposal		$ 850
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Brookfield Infrastructure Partners
Business Acquisition [Line Items]
Gain (loss) on sale of investment				$ 432
Proceeds from assets sold				1,100
Property, plant and equipment				298					298
Goodwill				$ 215					$ 215
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Hudson Yards North Tower Holdings LLC
Business Acquisition [Line Items]
Cash proceeds from sale of businesses and interest in affiliates					$ 2,081
Gain (loss) on sale of investment					$ (100)
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Hulu
Business Acquisition [Line Items]
Cash proceeds from sale of businesses and interest in affiliates						$ 1,430
Gain (loss) on sale of investment						$ 740

Property, Plant And Equipment_2

Property, Plant And Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 327,751	$ 333,538
Accumulated depreciation and amortization	200,436	203,410
Property, plant and equipment - net	127,315	130,128	$ 131,473
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	2,571	2,651
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 39,418	38,924
Buildings and improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Buildings and improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	44 years
Central office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 95,981	96,061
Central office equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Central office equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years
Cable, wiring and conduit
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 75,409	72,042
Cable, wiring and conduit | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Cable, wiring and conduit | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	50 years
Satellites
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 908	2,489
Satellites | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	14 years
Satellites | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	17 years
Other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 90,883	94,951
Other equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Other equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	20 years
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 18,482	22,244
Software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	7 years
Under construction
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 4,099	$ 4,176

Property, Plant And Equipment_3

Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 20,277	$ 20,285	$ 20,083
Video | Communications
Property, Plant and Equipment [Line Items]
Impairment charge recorded	$ 7,255
Video | Communications | Property, Plant and Equipment
Property, Plant and Equipment [Line Items]
Impairment charge recorded	$ 1,681
Copper Network Assets
Property, Plant and Equipment [Line Items]
Noncash pre-tax charge to abandon copper assets			1,290
Software
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 3,483	$ 3,313	$ 3,092

Leases (Narrative) (Details)

Leases (Narrative) (Details) - Maximum	Dec. 31, 2020
Lessee, Lease, Description [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) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 5,896	$ 5,684
Finance lease cost:
Amortization of right-of-use assets	287	271
Interest on lease obligation	156	169
Total finance lease cost	$ 443	$ 440

Leases (Supplemental Cash Flow

Leases (Supplemental Cash Flow Information Related to Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities
Operating cash flows from operating leases	$ 4,852	$ 4,583
Supplemental Lease Cash Flow Disclosures
Operating lease right-of-use assets obtained in exchange for new operating lease obligations	$ 5,270	$ 7,818

Leases (Supplemental Balance Sh

Leases (Supplemental Balance Sheet Information Related to Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
Operating lease right-of-use assets	$ 24,714	$ 24,039
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accounts payable and accrued liabilities	Accounts payable and accrued liabilities
Accounts payable and accrued liabilities	$ 3,537	$ 3,451
Operating lease obligation	22,202	21,804
Total operating lease obligation	25,739	25,255
Finance Leases
Property, plant and equipment, at cost	3,586	3,534
Accumulated depreciation and amortization	(1,361)	(1,296)
Property, plant and equipment, net	$ 2,225	$ 2,238
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant and Equipment – Net	Property, Plant and Equipment – Net
Current portion of long-term debt	$ 189	$ 162
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Debt maturing within one year	Debt maturing within one year
Long-term debt	$ 1,847	$ 1,872
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-Term Debt	Long-Term Debt
Total finance lease obligation	$ 2,036	$ 2,034
Weighted-Average Remaining Lease Term (years), Operating leases	8 years 6 months	8 years 4 months 24 days
Weighted-Average Remaining Lease Term (years), Finance leases	9 years 10 months 24 days	10 years 3 months 18 days
Weighted-Average Discount Rate, Operating leases	4.10%	4.20%
Weighted-Average Discount Rate, Finance leases	8.10%	8.40%

Leases (Future Minimum Maturiti

Leases (Future Minimum Maturities of Lease Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
2021	$ 4,808
2022	4,527
2023	4,094
2024	3,560
2025	2,904
Thereafter	11,230
Total lease payments	31,123
Less: imputed interest	(5,384)
Total	25,739	$ 25,255
Finance Leases
2021	350
2022	333
2023	300
2024	276
2025	272
Thereafter	1,609
Total lease payments	3,140
Less: imputed interest	(1,104)
Total	$ 2,036	$ 2,034

Goodwill And Other Intangible_3

Goodwill And Other Intangible Assets (Summary Of Changes In Carrying Amount Of Goodwill, By Segment) (Details) $ in Millions	Dec. 31, 2020USD ($)reporting_unit	Dec. 31, 2020USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Oct. 01, 2020
Goodwill [Line Items]
Goodwill impairment				$ 10,465
Goodwill [Roll Forward]
Beginning balance				146,241	$ 146,370
Acquisitions				415	66
Impairments				(10,465)
Dispositions, currency exchange and other				(932)	(195)
Ending balance	$ 135,259	$ 135,259		135,259	146,241
Orbital slots
Goodwill [Line Items]
Impairment charge - intangible assets		4,373
Customer lists
Goodwill [Line Items]
Impairment charge - intangible assets		1,201
Communications
Goodwill [Line Items]
Goodwill impairment				8,253
Number of reporting units | reporting_unit	4
Goodwill [Roll Forward]
Beginning balance				100,234	100,551
Acquisitions				0	0
Impairments				(8,253)
Dispositions, currency exchange and other				(5)	(317)
Ending balance	$ 91,976	91,976		91,976	100,234
Communications | Entertainment Group
Goodwill [Line Items]
Percent fair values exceeded book values (less than)						10.00%
Communications | Video
Goodwill [Line Items]
Long-lived asset impairment		7,255
Goodwill impairment		8,253
Goodwill [Roll Forward]
Impairments		(8,253)
Communications | Consumer Wireline
Goodwill [Line Items]
Goodwill impairment		0
Goodwill [Roll Forward]
Impairments		0
WarnerMedia
Goodwill [Line Items]
Goodwill impairment				0
Number of reporting units | reporting_unit	4
Goodwill [Roll Forward]
Beginning balance				42,345	42,101
Acquisitions				415	66
Impairments				0
Dispositions, currency exchange and other				(313)	178
Ending balance	$ 42,447	42,447		42,447	42,345
WarnerMedia | Turner
Goodwill [Line Items]
Percent fair values exceeded book values (less than)						10.00%
WarnerMedia | Home Box Office
Goodwill [Line Items]
Percent fair values exceeded book values (less than)						10.00%
Latin America
Goodwill [Line Items]
Goodwill impairment				2,212
Number of reporting units | reporting_unit	2
Goodwill [Roll Forward]
Beginning balance				3,662	3,718
Acquisitions				0	0
Impairments				(2,212)
Dispositions, currency exchange and other				(614)	(56)
Ending balance	$ 836	$ 836		$ 836	$ 3,662
Latin America | Vrio | Latin America
Goodwill [Line Items]
Goodwill impairment			$ 2,212
Goodwill [Roll Forward]
Impairments			(2,212)
Latin America | Vrio | Latin America | Noncontrolling Interest
Goodwill [Line Items]
Goodwill impairment			105
Goodwill [Roll Forward]
Impairments			$ (105)

Goodwill And Other Intangible_4

Goodwill And Other Intangible Assets (Schedule Of Amortized Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	22 years 3 months 18 days
Gross Carrying Amount	$ 73,585	$ 82,150
Accumulated Amortization	16,910	25,392
Currency Translation Adjustment	$ (1,328)	(533)
Wireless licenses
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	24 years 7 months 6 days
Gross Carrying Amount	$ 2,979	2,981
Accumulated Amortization	271	156
Currency Translation Adjustment	$ (421)	(243)
Wireless licenses | Mexico
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		1,561
Orbital slots
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	15 years
Gross Carrying Amount	$ 5,825	0
Accumulated Amortization	0	0
Currency Translation Adjustment	$ 0	0
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	37 years 1 month 6 days
Gross Carrying Amount	$ 20,016	18,359
Accumulated Amortization	1,518	853
Currency Translation Adjustment	$ (442)	(6)
Distribution network
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	10 years
Gross Carrying Amount	$ 18,414	18,138
Accumulated Amortization	4,621	2,793
Currency Translation Adjustment	$ 0	0
Released television and film content
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	17 years 6 months
Gross Carrying Amount	$ 10,940	10,941
Accumulated Amortization	6,240	4,974
Currency Translation Adjustment	$ 0	0
Customer lists and relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	9 years 3 months 18 days
Gross Carrying Amount	$ 4,100	20,304
Accumulated Amortization	1,645	14,773
Currency Translation Adjustment	$ (460)	(281)
Other
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life	21 years 3 months 18 days
Gross Carrying Amount	$ 11,311	11,427
Accumulated Amortization	2,615	1,843
Currency Translation Adjustment	$ (5)	$ (3)

Goodwill And Other Intangible_5

Goodwill And Other Intangible Assets (Schedule Of Indefinite-Life Intangible Assets Not Subject To Amortization) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Indefinite-lived Intangible Assets [Line Items]
Total	$ 90,969	$ 101,392
Wireless licenses
Indefinite-lived Intangible Assets [Line Items]
Total	85,728	83,623
Orbital slots
Indefinite-lived Intangible Assets [Line Items]
Total	0	11,702
Trade names
Indefinite-lived Intangible Assets [Line Items]
Total	$ 5,241	$ 6,067

Goodwill And Other Intangible_6

Goodwill And Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Estimated economic useful life	22 years 3 months 18 days
Amortization expense for definite-life intangible assets for the year	$ 8,239	$ 7,932	$ 8,347
Estimated amortization expense in 2021	5,987
Estimated amortization expense in 2022	5,363
Estimated amortization expense in 2023	4,846
Estimated amortization expense in 2024	4,302
Estimated amortization expense in 2025	$ 4,046
Orbital slots
Finite-Lived Intangible Assets [Line Items]
Estimated economic useful life	15 years

Equity Method Investments (Narr

Equity Method Investments (Narrative) (Details) - Equity Method Investments	Dec. 31, 2020
SKY Mexico
Schedule of Equity Method Investments [Line Items]
Company's ownership interest in investee	41.30%
The CW
Schedule of Equity Method Investments [Line Items]
Company's ownership interest in investee	50.00%

Equity Method Investments (Reco

Equity Method Investments (Reconciliation Of Investments In Equity Affiliates) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity Method Investments [Roll Forward]
Beginning of year	$ 3,695	$ 6,245
Additional investments	178	448
Equity in net income (loss) of affiliates	95	6	$ (48)
Dividends and distributions received	(133)	(301)
Currency translation adjustments	(10)	(10)
Impairments	(146)	0
Other adjustments	(9)	(35)
End of year	1,780	3,695	$ 6,245
HBO LAG
Equity Method Investments [Roll Forward]
Acquisition of remaining interest in HBO LAG	(1,141)	0
CME
Equity Method Investments [Roll Forward]
Disposition of investments	(749)	0
Hudson Yards
Equity Method Investments [Roll Forward]
Disposition of investments	0	(1,681)
Hulu
Equity Method Investments [Roll Forward]
Disposition of investments	0	(689)
Game Show Network
Equity Method Investments [Roll Forward]
Disposition of investments	$ 0	$ (288)

Inventories And Theatrical Fi_3

Inventories And Theatrical Film And Television Production Costs (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Finite-Lived Intangible Assets [Line Items]
Other current assets	$ (20,231)	$ (20,231)	$ (18,364)
Inventories:
Less: current portion of inventory	(3,592)	(3,592)	(2,864)
Theatrical film production costs:
Released, less amortization	487	487	392
Completed and not released	616	616	437
In production	1,130	1,130	1,475
Development and pre-production	190	190	171
Television production costs:
Released, less amortization	2,495	2,495	2,199
Completed and not released	1,381	1,381	1,344
In production	2,353	2,353	2,208
Development and pre-production	90	90	57
Total theatrical film and television production costs	8,742	8,742	8,283
Total noncurrent inventories and theatrical film and television production costs	14,752	14,752	12,434
Film costs of released and completed and not released theatrical and television product	5,171	5,171
Programming Inventory Costs | ASU 2019-02
Finite-Lived Intangible Assets [Line Items]
Other current assets				$ 2,274
Other assets				$ 2,274
COVID-19 Pandemic
Unusual or Infrequent Item, or Both [Line Items]
Impairment based on change in estimates for various film titles	524
Total inventories
Inventories:
Total inventories	6,113	6,113	4,247
Less: current portion of inventory	(103)	(103)	(96)
Total noncurrent inventories	6,010	6,010	4,151
Programming costs, less amortization
Inventories:
Total inventories	6,010	6,010	4,151
Other inventory, primarily DVD and Blu-ray Discs
Inventories:
Total inventories	103	103	96
Film and Television Libraries
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, net	$ 4,699	$ 4,699	$ 5,967
Percentage of unamortized film costs	90.00%	90.00%
Amortization period for unamortized film costs		3 years
Film costs, amortized in next operating cycle		$ 3,111

Debt (Summary Of Long-Term Debt

Debt (Summary Of Long-Term Debt Of AT&T And Its Subsidiaries) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 165,451	$ 164,557
Unamortized (discount) premium - net	(9,710)	(2,996)
Unamortized issuance costs	(532)	(452)
Total notes and debentures	155,209	161,109
Finance lease obligations	2,036	2,034
Total long-term debt, including current maturities	157,245	163,143
Current maturities of long-term debt	(3,470)	(11,834)
Total long-term debt	153,775	151,309
Credit agreement borrowings
Debt Instrument [Line Items]
Carrying amount of notes and debentures	300	4,969
Fair value of interest rate swaps recorded in debt
Debt Instrument [Line Items]
Carrying amount of notes and debentures	20	26
Notes And Debentures Maturing 2020-2039 | Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 25,549	17,404
Notes And Debentures Maturing 2020-2039 | Notes and debentures | Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	0.98%
Notes And Debentures Maturing 2020-2039 | Notes and debentures | Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	2.99%
Notes And Debentures Maturing 2020-2050 | Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 110,317	102,595
Notes And Debentures Maturing 2020-2050 | Notes and debentures | Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	3.00%
Notes And Debentures Maturing 2020-2050 | Notes and debentures | Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	4.99%
Notes And Debentures Maturing 2020-2095 | Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 24,259	34,513
Notes And Debentures Maturing 2020-2095 | Notes and debentures | Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	5.00%
Notes And Debentures Maturing 2020-2095 | Notes and debentures | Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	6.99%
Notes And Debentures Maturing 2020-2097 | Notes and debentures
Debt Instrument [Line Items]
Carrying amount of notes and debentures	$ 5,006	$ 5,050
Notes And Debentures Maturing 2020-2097 | Notes and debentures | Minimum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	7.00%
Notes And Debentures Maturing 2020-2097 | Notes and debentures | Maximum
Debt Instrument [Line Items]
Debt instrument - stated percentage rate	9.15%

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2007
Debt Instrument [Line Items]
Outstanding debt	$ 165,451,000,000	$ 164,557,000,000
Weighted-average interest rate	4.10%	4.40%
Debt Instrument - principal/face amount	$ 32,241,000,000
Debt Issued in Foreign Markets
Debt Instrument [Line Items]
Outstanding debt	43,399,000,000	$ 42,485,000,000
Zero Coupon
Debt Instrument [Line Items]
Debt Instrument - principal/face amount			$ 500,000,000
Debt instrument - redemption amount	$ 592,000,000

Debt (Debt Maturing Within One

Debt (Debt Maturing Within One Year) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Current maturities of long-term debt	$ 3,470	$ 11,834
Bank borrowings	0	4
Total	$ 3,470	$ 11,838

Debt (Long-Term Debt - Schedule

Debt (Long-Term Debt - Scheduled Repayments) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Debt repayments
2021	$ 3,418
2022	5,951
2023	7,779
2024	7,849
2025	6,389
Thereafter	$ 134,268
Weighted-average interest rate
2021	3.80%
2022	3.30%
2023	3.40%
2024	3.30%
2025	3.90%
Thereafter	4.20%

Debt (Financing Activities) (Na

Debt (Financing Activities) (Narrative) (Details) - USD ($)	1 Months Ended			12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Aug. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Net proceeds received from issuance of long-term debt				$ 31,988,000,000	$ 17,039,000,000	$ 41,875,000,000
Debt Instrument - principal/face amount	$ 32,241,000,000			$ 32,241,000,000
Weighted maturity period				20 years
Weighted average coupon				3.20%
Repayment of long-term debt				$ 39,964,000,000	$ 27,592,000,000	$ 52,643,000,000
Weighted-average interest rate	4.10%			4.10%	4.40%
Various Notes
Debt Instrument [Line Items]
Weighted average coupon				3.20%
Amount of borrowings repaid / debt exchanged				$ 39,758,000,000
AT&T Global Notes and Subsidiary Notes due 2021 to 2025
Debt Instrument [Line Items]
Repayment of long-term debt			$ 11,384,000,000
AT&T and Subsidiary Notes
Debt Instrument [Line Items]
Amount of borrowings repaid / debt exchanged		$ 17,677,000,000
Repayment of long-term debt		1,459,000,000
Three New Series of AT&T Global Notes due 2053 to 2059
Debt Instrument [Line Items]
Net proceeds received from issuance of long-term debt		$ 21,500,000,000
AT&T and Subsidiary Notes due 2026 to 2048
Debt Instrument [Line Items]
Amount of borrowings repaid / debt exchanged	$ 8,280,000,000
Repayment of long-term debt	8,000,000
Two New Series of Global Notes due 2033 to 2057
Debt Instrument [Line Items]
Net proceeds received from issuance of long-term debt	$ 9,678,000,000
Minimum | AT&T and Subsidiary Notes
Debt Instrument [Line Items]
Weighted-average interest rate		4.35%
Minimum | Three New Series of AT&T Global Notes due 2053 to 2059
Debt Instrument [Line Items]
Weighted-average interest rate		3.50%
Minimum | AT&T and Subsidiary Notes due 2026 to 2048
Debt Instrument [Line Items]
Weighted-average interest rate	2.95%			2.95%
Minimum | Two New Series of Global Notes due 2033 to 2057
Debt Instrument [Line Items]
Weighted-average interest rate	2.55%			2.55%
Maximum | AT&T and Subsidiary Notes
Debt Instrument [Line Items]
Weighted-average interest rate		8.75%
Maximum | Three New Series of AT&T Global Notes due 2053 to 2059
Debt Instrument [Line Items]
Weighted-average interest rate		3.65%
Maximum | AT&T and Subsidiary Notes due 2026 to 2048
Debt Instrument [Line Items]
Weighted-average interest rate	7.125%			7.125%
Maximum | Two New Series of Global Notes due 2033 to 2057
Debt Instrument [Line Items]
Weighted-average interest rate	3.80%			3.80%

Debt (Credit Facilities) (Narra

Debt (Credit Facilities) (Narrative) (Details)	Jan. 29, 2021USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2020USD ($)renewal_option	Jan. 31, 2021USD ($)	Nov. 30, 2020USD ($)	Apr. 30, 2020USD ($)
Line of Credit Facility [Line Items]
Maximum net debt-to-EBITDA financial ratio covenant			3.5
Minimum percentage of facility commitments required for lender involvement in option to extend commitments			50.00%
Number of extension options | renewal_option			2
Term of each optional extension period			1 year
Subsequent Event
Line of Credit Facility [Line Items]
Commercial paper outstanding				$ 6,100,000,000
High Credit Rating
Line of Credit Facility [Line Items]
Credit agreement - commitment fee percentage			0.07%
Moderate Credit Rating
Line of Credit Facility [Line Items]
Credit agreement - commitment fee percentage			0.08%
Low Credit Rating
Line of Credit Facility [Line Items]
Credit agreement - commitment fee percentage			0.10%
Very Low Credit Rating
Line of Credit Facility [Line Items]
Credit agreement - commitment fee percentage			0.125%
Federal Funds Rate
Line of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			0.50%
LIBOR
Line of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			1.00%
Additional Margin Upon Default
Line of Credit Facility [Line Items]
Credit agreement - basis spread of variable rate			2.00%
Term Loan Credit Agreement | September 2019 Term Loan | Bank of America, N.A.
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity		$ 1,300,000,000
Credit agreement - advances outstanding		1,300,000,000
Term Loan Credit Agreement | 1.25 year Tranche A Facility Term Loan | Bank of America, N.A.
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity		$ 400,000,000
Credit agreement - term of Loan		1 year 3 months
Credit agreement - advances outstanding		$ 400,000,000
Term Loan Credit Agreement | 2.25 year Tranche B Facility Term Loan | Bank of America, N.A.
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity		$ 400,000,000
Credit agreement - term of Loan		2 years 3 months
Credit agreement - advances outstanding		$ 400,000,000
Term Loan Credit Agreement | 3.25 year Tranche C Facility Term Loan | Bank of America, N.A.
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity		$ 500,000,000
Credit agreement - term of Loan		3 years 3 months
Credit agreement - advances outstanding		$ 500,000,000
Term Loan Credit Agreement | April 2020 Term Loan | 11 Commercial Banks And Bank of America, N.A.
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity						$ 5,500,000,000
Term Loan Credit Agreement | January 2021 Term Loan | Bank of America, N.A. | Subsequent Event
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity	$ 14,700,000,000
Credit agreement - term of Loan	364 days
Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity					$ 15,000,000,000
Revolving Credit Facility | Credit Agreement One, Amended Credit Agreement
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity					7,500,000,000
Credit agreement - advances outstanding			$ 0
Revolving Credit Facility | Credit Agreement Two
Line of Credit Facility [Line Items]
Credit agreement - maximum borrowing capacity					$ 7,500,000,000
Credit agreement - advances outstanding			$ 0

Fair Value Measurements And D_3

Fair Value Measurements And Disclosure (Long-Term Debt And Other Financial Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Bank borrowings	$ 0	$ 4
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and debentures	155,209	161,109
Bank borrowings	0	4
Investment securities	3,249	3,723
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes and debentures	187,224	182,124
Bank borrowings	0	4
Investment securities	$ 3,249	$ 3,723

Fair Value Measurements And D_4

Fair Value Measurements And Disclosure (Fair Value Leveling) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Debt Securities	$ 1,479	$ 1,444
Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		2
Cross-currency swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	1,721	172
Liability Derivatives	(1,814)	(3,187)
Interest rate locks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		11
Liability Derivatives		(95)
Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	6	89
Liability Derivatives	(9)
Fixed income equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	236	229
Domestic equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	1,010	844
International equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	180	183
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Debt Securities	0	0
Level 1 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		0
Level 1 | Cross-currency swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives	0	0
Level 1 | Interest rate locks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		0
Liability Derivatives		0
Level 1 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives	0
Level 1 | Fixed income equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	236	229
Level 1 | Domestic equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	1,010	844
Level 1 | International equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	180	183
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Debt Securities	1,479	1,444
Level 2 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		2
Level 2 | Cross-currency swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	1,721	172
Liability Derivatives	(1,814)	(3,187)
Level 2 | Interest rate locks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		11
Liability Derivatives		(95)
Level 2 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	6	89
Liability Derivatives	(9)
Level 2 | Fixed income equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	0	0
Level 2 | Domestic equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	0	0
Level 2 | International equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Debt Securities	0	0
Level 3 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		0
Level 3 | Cross-currency swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives	0	0
Level 3 | Interest rate locks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives		0
Liability Derivatives		0
Level 3 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives	0	0
Liability Derivatives	0
Level 3 | Fixed income equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	0	0
Level 3 | Domestic equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	0	0
Level 3 | International equities | Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	$ 0	$ 0

Fair Value Measurements And D_5

Fair Value Measurements And Disclosure (Gain and Losses on Equity Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Total gains (losses) recognized on equity securities	$ 171	$ 301	$ (130)
Gains (losses) recognized on equity securities sold	(25)	100	(10)
Unrealized gains (losses) recognized on equity securities held at end of period	$ 196	$ 201	$ (120)

Fair Value Measurements And D_6

Fair Value Measurements And Disclosure (Narrative) (Details)	1 Months Ended	12 Months Ended
	May 31, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019USD ($)
Fair Value Disclosures [Abstract]
Available-for-sale debt securities		$ 1,479,000,000		$ 1,444,000,000
Available-for-sale debt securities - maturities less than 1 year		29,000,000
Available-for-sale debt securities - maturities within 1 to 3 years		159,000,000
Available-for-sale debt securities - maturities within 3 to 5 years		179,000,000
Available-for-sale debt securities - maturities for 5 or more years		1,112,000,000
Fair Value, Option, Quantitative Disclosures [Line Items]
Anticipated reclassification of holding losses during the next 12 months - cash flow hedges		92,000,000
Aggregate principal amount of debt		32,241,000,000
Net losses on net investment hedges recognized in accumulated OCI		147,000,000
Collateral submitted to counterparty		53,000,000		204,000,000
Collateral received from counterparty		694,000,000		44,000,000
Collateral contingently payable to the counterparty		33,000,000
Nonrecurring Fair Value Measurements
Fair Value, Option, Quantitative Disclosures [Line Items]
Nonrecurring fair value measurements				$ 0
Communications | Video | Nonrecurring Fair Value Measurements
Fair Value, Option, Quantitative Disclosures [Line Items]
Nonrecurring fair value measurements		9,744,000,000
Property, plant, and equipment, fair value measurements		2,258,000,000
Communications | Video | Nonrecurring Fair Value Measurements | Orbital slots
Fair Value, Option, Quantitative Disclosures [Line Items]
Finite-lived intangible assets, fair value measurements		5,873,000,000
Communications | Video | Nonrecurring Fair Value Measurements | Customer lists
Fair Value, Option, Quantitative Disclosures [Line Items]
Finite-lived intangible assets, fair value measurements		1,613,000,000
WarnerMedia | Warner Bros. | Nonrecurring Fair Value Measurements
Fair Value, Option, Quantitative Disclosures [Line Items]
Film costs, fair value measurements		844,000,000
Measurement Input, Entity Credit Risk
Fair Value, Option, Quantitative Disclosures [Line Items]
Collateral contingently payable to the counterparty		676,000,000
Measurement Input, Entity Credit Risk | Communications | DirecTV
Fair Value, Option, Quantitative Disclosures [Line Items]
Collateral contingently payable to the counterparty		$ 134,000,000
Net Investment Hedging
Fair Value, Option, Quantitative Disclosures [Line Items]
Aggregate principal amount of debt | €			€ 1,450,000,000
Interest rate locks | Cash Flow Hedging
Fair Value, Option, Quantitative Disclosures [Line Items]
Payment for hedge	$ 731,000,000

Fair Value Measurements And D_7

Fair Value Measurements And Disclosure (Notional Amount Of Our Outstanding Derivative Positions) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional amounts of outstanding derivative positions	$ 40,835	$ 46,947
Interest rate swaps
Derivative [Line Items]
Notional amounts of outstanding derivative positions	0	853
Cross-currency swaps
Derivative [Line Items]
Notional amounts of outstanding derivative positions	40,745	42,325
Interest rate locks
Derivative [Line Items]
Notional amounts of outstanding derivative positions	0	3,500
Foreign exchange contracts
Derivative [Line Items]
Notional amounts of outstanding derivative positions	$ 90	$ 269

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on interest rate swaps	$ (6)	$ 58	$ (12)
Gain (Loss) on long-term debt	6	(58)	12
Cross-currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated OCI	(378)	(1,066)	(825)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated OCI	3	10	51
Foreign exchange contracts | Other income (expense) - net
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated OCI into income	(3)	6	39
Interest rate locks
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) recognized in accumulated OCI	(648)	(84)	0
Interest rate locks | Interest income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated OCI into income	$ (84)	$ (63)	$ (58)

Income Taxes (Components Of Def

Income Taxes (Components Of Deferred Tax Liabilities (Assets)) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Depreciation and amortization	$ 46,952	$ 44,896
Licenses and nonamortizable intangibles	13,930	17,355
Employee benefits	(5,279)	(5,143)
Deferred fulfillment costs	2,691	3,050
Net operating loss and other carryforwards	(7,355)	(7,301)
Other – net	4,562	1,536
Subtotal	55,501	54,393
Deferred tax assets valuation allowance	4,773	4,941
Net deferred tax liabilities	60,274	59,334
Noncurrent deferred tax liabilities	60,472	59,502
Less: Noncurrent deferred tax assets	$ (198)	$ (168)

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Net operating and capital loss carryforwards (tax effected) for federal income tax purposes	$ 585
Net operating and capital loss carryforwards (tax effected) for state income tax purposes	916
Net operating and capital loss carryforwards (tax effected) for foreign income tax purposes	2,763
Amount of deposits that reduced UTB balance	702	$ 2,584
Accrued interest and penalties included in unrecognized tax benefits balance at year end	2,450	2,708
Net interest and penalty expense included in income tax expense	149	$ 267	$ 1,290
Federal
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	1,080
State
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	$ 2,011

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, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 10,979	$ 10,358
Increases for tax positions related to the current year	1,580	903
Increases for tax positions related to prior years	112	1,106
Decreases for tax positions related to prior years	(994)	(1,283)
Lapse of statute of limitations	(24)	(32)
Settlements	(1,646)	(283)
Current year acquisitions	0	205
Foreign currency effects	(6)	5
Balance at end of year	10,001	10,979
Accrued interest and penalties	2,450	2,708
Gross unrecognized income tax benefits	12,451	13,687
Less: Deferred federal and state income tax benefits	(878)	(886)
Less: Tax attributable to timing items included above	(3,588)	(4,320)
Total UTB that, if recognized, would impact the effective income tax rate as of the end of the year	$ 7,985	$ 8,481

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal:
Current	$ (687)	$ 584	$ 3,258
Deferred	1,039	1,656	277
Total federal income tax	352	2,240	3,535
State and local:
Current	(6)	603	513
Deferred	263	144	473
Total state and local income tax	257	747	986
Foreign:
Current	413	605	539
Deferred	(57)	(99)	(140)
Total foreign income tax	356	506	399
Total	$ 965	$ 3,493	$ 4,920

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. income (loss) before income taxes	$ (452)	$ 18,301	$ 25,379
Foreign income (loss) before income taxes	(2,404)	167	(506)
Income (Loss) Before Income Taxes	$ (2,856)	$ 18,468	$ 24,873

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Income Tax Expense (Benefit) Based On Federal Statutory Rate To Amount Per Effective Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Taxes computed at federal statutory rate	$ (600)	$ 3,878	$ 5,223
Increases (decreases) in income taxes resulting from:
State and local income taxes - net of federal income tax benefit	193	611	738
Enactment date and measurement period adjustments from the Act	0	0	(718)
Tax on foreign investments	(141)	(115)	(466)
Noncontrolling interest	(285)	(230)	(121)
Permanent items and R&D credit	(239)	(285)	(189)
Audit resolutions	(112)	(156)	544
Divestitures	107	0	0
Goodwill impairment	2,120	0	0
Other - net	(78)	(210)	(91)
Total	$ 965	$ 3,493	$ 4,920
Effective Tax Rate	(33.80%)	18.90%	19.80%

Pension And Postretirement Be_3

Pension And Postretirement Benefits (Narrative) (Details) - USD ($)	1 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Combined net pension and postretirement cost				$ 711,000,000	$ 2,762,000,000	$ (4,251,000,000)
Increase (decrease) in plan benefit obligations due to change in assumed rates				$ (2,992,000,000)	$ (2,002,000,000)	(1,148,000,000)
Composite rate of compensation increase for determining benefit obligation	3.00%	3.00%		3.00%	3.00%
Discretionary contributions to postretirement plan	$ 425,000,000	$ 200,000,000
Debt-financed shares held by ESOPs (allocated or unallocated)	0			$ 0
Benefit cost of the contributory savings plans				814,000,000	$ 793,000,000	724,000,000
Forecast
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates			$ 277,000,000
Assumptions used, percentage change in weighted-average interest crediting rate that would impact pension benefit obligation			(0.50%)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits				0	81,000,000
Accumulated benefit obligation for pension plans	$ 60,848,000,000	$ 58,150,000,000		60,848,000,000	58,150,000,000
Combined net pension and postretirement cost				$ 1,450,000,000	$ 2,393,000,000	$ (909,000,000)
Discount rate for determining projected benefit obligation	2.70%	3.40%		2.70%	3.40%	4.50%
Decrease in discount rate over prior year				0.70%	1.10%
Increase (decrease) in plan benefit obligations due to change in assumed rates				$ 5,594,000,000	$ 8,018,000,000
Long-term rate of return on plan assets				7.00%	7.00%	7.00%
Composite rate of compensation increase for determining benefit obligation	3.00%	3.00%		3.00%	3.00%	3.00%
Preferred equity interest value	$ 54,606,000,000	$ 53,530,000,000		$ 54,606,000,000	$ 53,530,000,000	$ 51,681,000,000
Aggregate percentage of the fair value of investments to the fair value of total plan assets held as of the measurement date	11.00%			11.00%
Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Preferred equity interest value	$ 8,390,000,000	11,639,000,000		$ 8,390,000,000	11,639,000,000	11,333,000,000
Pension Benefits | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Preferred equity interest value	5,771,000,000	8,806,000,000		5,771,000,000	8,806,000,000
Pension Benefits | Preferred interest | Level 3
Defined Benefit Plan Disclosure [Line Items]
Preferred equity interest value	$ 5,771,000,000	8,806,000,000		5,771,000,000	8,806,000,000
Pension Benefits | Mobility II, LLC | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Preferred equity interest value held by pension trust		$ 8,806,000,000			8,806,000,000
Value of portion of preferred interest sold to third party investors				2,885,000,000
Pension Benefits | Forecast
Defined Benefit Plan Disclosure [Line Items]
Long-term rate of return on plan assets			6.75%
Downward adjustment to expected long-term rate of return on plan assets			0.25%
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits				0	0
Combined net pension and postretirement cost				$ (739,000,000)	$ 369,000,000	$ (3,342,000,000)
Discount rate for determining projected benefit obligation	2.40%	3.20%		2.40%	3.20%	4.40%
Decrease in discount rate over prior year				0.80%	1.20%
Increase (decrease) in plan benefit obligations due to change in assumed rates				$ 1,311,000,000	$ 2,399,000,000
Long-term rate of return on plan assets				4.75%	5.75%	5.75%
Composite rate of compensation increase for determining benefit obligation	3.00%	3.00%		3.00%	3.00%	3.00%
Preferred equity interest value	$ 3,843,000,000	$ 4,145,000,000		$ 3,843,000,000	$ 4,145,000,000	$ 4,277,000,000
Aggregate percentage of the fair value of investments to the fair value of total plan assets held as of the measurement date	1.00%			1.00%
Postretirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Preferred equity interest value	$ 4,000,000	$ 32,000,000		$ 4,000,000	32,000,000	13,000,000
Postretirement Benefits | Forecast
Defined Benefit Plan Disclosure [Line Items]
Long-term rate of return on plan assets			4.50%
Downward adjustment to expected long-term rate of return on plan assets			0.25%
Healthcare Benefits | Prescription Drug Cost - Eligible Participants
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates					$ (102,000,000)
Assumed annual and ultimate health care cost trend rate for next fiscal year	4.00%			4.00%
Estimated annual growth rate for health care cost	4.00%	4.50%		4.00%	4.50%
Healthcare Benefits | Medical Cost - Eligible Participants
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) in plan benefit obligations due to change in assumed rates					$ (102,000,000)
Assumed annual and ultimate health care cost trend rate for next fiscal year	4.00%			4.00%
Estimated annual growth rate for health care cost	4.00%	4.50%		4.00%	4.50%
Healthcare Benefits | Administrative Expense
Defined Benefit Plan Disclosure [Line Items]
Percent of growth assumed				2.50%
Healthcare Benefits | Administrative Expense | Forecast
Defined Benefit Plan Disclosure [Line Items]
Percent of growth assumed			2.50%
Healthcare Benefits | Dental Claims
Defined Benefit Plan Disclosure [Line Items]
Percent of growth assumed				3.00%
Healthcare Benefits | Dental Claims | Forecast
Defined Benefit Plan Disclosure [Line Items]
Percent of growth assumed			3.00%
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Combined net pension and postretirement cost				$ 330,000,000	$ 438,000,000
Discount rate for determining projected benefit obligation	2.30%	3.20%		2.30%	3.20%
Projected benefit obligation	$ 2,687,000,000	$ 2,605,000,000		$ 2,687,000,000	$ 2,605,000,000
Deferred compensation expense				$ 183,000,000	$ 199,000,000	$ 128,000,000

Pension And Postretirement Be_4

Pension And Postretirement Benefits (Change In The Projected Benefit Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Actuarial (gain) loss	$ 4,169	$ 5,171	$ (3,412)
Pension Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	59,873	55,439
Service cost - benefits earned during the period	1,029	1,019	1,116
Interest cost on projected benefit obligation	1,687	1,960	2,092
Amendments	(340)	0
Actuarial (gain) loss	5,054	7,734
Special termination benefits	0	81
Benefits paid	(5,124)	(6,356)
Curtailment	(1)	0
Plan transfers	(20)	(4)
Benefit obligation at end of year	62,158	59,873	55,439
Postretirement Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	16,041	19,378
Service cost - benefits earned during the period	53	71	109
Interest cost on projected benefit obligation	416	675	778
Amendments	(2,655)	(4,590)
Actuarial (gain) loss	1,423	2,050
Special termination benefits	0	0
Benefits paid	(1,370)	(1,543)
Curtailment	0	0
Plan transfers	20	0
Benefit obligation at end of year	$ 13,928	$ 16,041	$ 19,378

Pension And Postretirement Be_5

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, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 53,530	$ 51,681
Actual return on plan assets	6,199	8,207
Benefits paid	(5,124)	(6,356)
Contributions	2	2
Plan transfers	(1)	(4)
Fair value of plan assets at end of year	54,606	53,530
Unfunded status at end of year	(7,552)	(6,343)
Postretirement Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	4,145	4,277
Actual return on plan assets	302	609
Benefits paid	(1,029)	(941)
Contributions	425	200
Plan transfers	0	0
Fair value of plan assets at end of year	3,843	4,145
Unfunded status at end of year	$ (10,085)	$ (11,896)

Pension And Postretirement Be_6

Pension And Postretirement Benefits (Employee Benefit Obligation Amounts Recognized) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension obligations and other postemployment obligations	$ 1,415	$ 1,528
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Current portion of employee benefit obligation	0	0
Employee benefit obligation	(7,552)	(6,343)
Net amount recognized	(7,552)	(6,343)
Pension Benefits | International
Defined Benefit Plan Disclosure [Line Items]
Pension obligations and other postemployment obligations	553
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Current portion of employee benefit obligation	(1,213)	(1,365)
Employee benefit obligation	(8,872)	(10,531)
Net amount recognized	(10,085)	$ (11,896)
Postretirement Benefits | International
Defined Benefit Plan Disclosure [Line Items]
Pension obligations and other postemployment obligations	$ 1,299

Pension And Postretirement Be_7

Pension And Postretirement Benefits (Net Periodic Benefit Cost (Credit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Net pension and postretirement cost (credit)	$ 711	$ 2,762	$ (4,251)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost – benefits earned during the period	1,029	1,019	1,116
Interest cost on projected benefit obligation	1,687	1,960	2,092
Expected return on assets	(3,557)	(3,561)	(3,190)
Amortization of prior service credit	(113)	(113)	(115)
Actuarial (gain) loss	2,404	3,088	(812)
Net pension and postretirement cost (credit)	1,450	2,393	(909)
Curtailment gain	(1)
Special termination benefits		81
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost – benefits earned during the period	53	71	109
Interest cost on projected benefit obligation	416	675	778
Expected return on assets	(178)	(227)	(304)
Amortization of prior service credit	(2,329)	(1,820)	(1,635)
Actuarial (gain) loss	1,299	1,670	(2,290)
Net pension and postretirement cost (credit)	$ (739)	$ 369	$ (3,342)

Pension And Postretirement Be_8

Pension And Postretirement Benefits (Other Changes Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Roll Forward]
Prior service (cost) credit	$ 2,250	$ 3,457	$ 830
Amortization of prior service credit	(1,841)	(1,459)	(1,322)
Pension Benefits
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Roll Forward]
Balance at beginning of year	361	447	571
Prior service (cost) credit	250	0	(37)
Amortization of prior service credit	(86)	(86)	(87)
Total recognized in other comprehensive (income) loss	164	(86)	(124)
Balance at end of year	525	361	447
Postretirement Benefits
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Roll Forward]
Balance at beginning of year	8,171	6,086	6,456
Prior service (cost) credit	2,001	3,457	864
Amortization of prior service credit	(1,756)	(1,372)	(1,234)
Total recognized in other comprehensive (income) loss	245	2,085	(370)
Balance at end of year	$ 8,416	$ 8,171	$ 6,086

Pension and Postretirement Be_9

Pension and Postretirement Benefits (Weighted Average Assumptions - Projected Benefit Obligation And Net Pension And Postemployment Benefit Cost) (Details) - USD ($) $ in Millions	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
Defined Benefit Plan Disclosure [Line Items]
Composite rate of compensation increase for determining benefit obligation	3.00%					3.00%	3.00%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Weighted-average discount rate for determining benefit obligation at December 31	3.40%					2.70%	3.40%	4.50%
Weighted-average interest credit rate for cash balance pension programs	3.30%					3.10%	3.30%	3.70%
Long-term rate of return on plan assets						7.00%	7.00%	7.00%
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%
Assumptions used, percentage change in weighted-average interest crediting rate that would impact pension benefit obligation						0.50%
Effect of 0.50% increase in weighted-average interest crediting rate, increase to pension benefit obligation						$ 130
Pension Benefits | Service Cost
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.50%	3.90%	4.30%	4.60%		3.60%	4.10%	4.20%
Pension Benefits | Interest Cost
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.00%	3.20%	3.70%	4.20%		2.90%	3.50%	3.80%
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Weighted-average discount rate for determining benefit obligation at December 31	3.20%					2.40%	3.20%	4.40%
Weighted-average interest credit rate for cash balance pension programs	0.00%					0.00%	0.00%	0.00%
Long-term rate of return on plan assets						4.75%	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 Benefits | Service Cost
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	3.40%				4.70%	3.50%	4.40%	4.30%
Postretirement Benefits | Interest Cost
Defined Benefit Plan Disclosure [Line Items]
Discount rate in effect for determining net cost	2.70%				4.00%	2.70%	3.70%	3.60%

Pension And Postretirement B_10

Pension And Postretirement Benefits (Schedule Of Defined Benefit Plan Targeted And Actual Plan Asset Allocations) (Details)	Dec. 31, 2020	Dec. 31, 2019
Pension Assets
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	100.00%	100.00%
Pension Assets | Domestic
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	19.00%	17.00%
Pension Assets | Domestic | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	16.00%
Pension Assets | Domestic | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	26.00%
Pension Assets | International
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	15.00%	12.00%
Pension Assets | International | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	10.00%
Pension Assets | International | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	20.00%
Pension Assets | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	35.00%	35.00%
Pension Assets | Fixed income securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	37.00%
Pension Assets | Fixed income securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	47.00%
Pension Assets | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	8.00%	9.00%
Pension Assets | Real estate and real assets | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	8.00%
Pension Assets | Real estate and real assets | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	18.00%
Pension Assets | Private equity
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	9.00%	8.00%
Pension Assets | Private equity | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	5.00%
Pension Assets | Private equity | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	15.00%
Pension Assets | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	10.00%	17.00%
Pension Assets | Preferred interest | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	6.00%
Pension Assets | Preferred interest | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	16.00%
Pension Assets | Other
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	4.00%	2.00%
Pension Assets | Other | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%
Pension Assets | Other | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	5.00%
Postretirement (VEBA) Assets
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	100.00%	100.00%
Postretirement (VEBA) Assets | Domestic
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	19.00%	20.00%
Postretirement (VEBA) Assets | Domestic | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	14.00%
Postretirement (VEBA) Assets | Domestic | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	24.00%
Postretirement (VEBA) Assets | International
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	14.00%	12.00%
Postretirement (VEBA) Assets | International | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	9.00%
Postretirement (VEBA) Assets | International | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	19.00%
Postretirement (VEBA) Assets | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	45.00%	52.00%
Postretirement (VEBA) Assets | Fixed income securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	40.00%
Postretirement (VEBA) Assets | Fixed income securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	50.00%
Postretirement (VEBA) Assets | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	1.00%	1.00%
Postretirement (VEBA) Assets | Real estate and real assets | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%
Postretirement (VEBA) Assets | Real estate and real assets | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	6.00%
Postretirement (VEBA) Assets | Private equity
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	1.00%	2.00%
Postretirement (VEBA) Assets | Private equity | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%
Postretirement (VEBA) Assets | Private equity | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	6.00%
Postretirement (VEBA) Assets | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%	0.00%
Postretirement (VEBA) Assets | Preferred interest | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%
Postretirement (VEBA) Assets | Preferred interest | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	0.00%
Postretirement (VEBA) Assets | Other
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	20.00%	13.00%
Postretirement (VEBA) Assets | Other | Minimum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	15.00%
Postretirement (VEBA) Assets | Other | Maximum
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	25.00%

Pension And Postretirement B_11

Pension And Postretirement Benefits (Schedule Of Fair Value Of Pension And Postretirement Assets And Liabilities By Level) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 54,606	$ 53,530	$ 51,681
Pension Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	42,793	43,195
Pension Benefits | Non-interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	173	85
Pension Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	7	529
Pension Benefits | Foreign currency contracts
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	3	5
Pension Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	9,795	8,072
Pension Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	4,844	3,946
Pension Benefits | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	5,771	8,806
Pension Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	11,095	10,473
Pension Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	6,039	6,172
Pension Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	443	524
Pension Benefits | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	2,544	2,817
Pension Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	2,056	1,761
Pension Benefits | Receivable for variation margin
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	23	5
Pension Benefits | Investments sold short and other liabilities at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(459)	(515)
Pension Benefits | Private equity funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 5,154	$ 4,544
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Assets held at net asset value practical expedient	Assets held at net asset value practical expedient
Pension Benefits | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 1,694	$ 2,062
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Assets held at net asset value practical expedient	Assets held at net asset value practical expedient
Pension Benefits | Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 7,706	$ 5,710
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Assets held at net asset value practical expedient	Assets held at net asset value practical expedient
Pension Benefits | Other assets (liabilities)
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ (2,282)	$ (1,466)
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	3,843	4,145	4,277
Postretirement Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	2,020	2,301
Postretirement Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	799	549
Postretirement Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	363	438
Postretirement Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	282	265
Postretirement Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	315	530
Postretirement Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	139	189
Postretirement Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	94	294
Postretirement Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	28	36
Postretirement Benefits | Securities lending payable and other liabilities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(30)	(36)
Postretirement Benefits | Private equity funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 24	$ 66
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Assets held at net asset value practical expedient	Assets held at net asset value practical expedient
Postretirement Benefits | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 22	$ 27
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Assets held at net asset value practical expedient	Assets held at net asset value practical expedient
Postretirement Benefits | Commingled funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 1,843	$ 1,797
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Assets held at net asset value practical expedient	Assets held at net asset value practical expedient
Postretirement Benefits | Other assets (liabilities)
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ (36)	$ (10)
Level 1, 2, and 3 | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	42,334	42,680
Level 1, 2, and 3 | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	1,990	2,265
Level 1 | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	14,979	12,255
Level 1 | Pension Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	15,429	12,768
Level 1 | Pension Benefits | Non-interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	173	85
Level 1 | Pension Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	7	529
Level 1 | Pension Benefits | Foreign currency contracts
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Pension Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	9,784	8,068
Level 1 | Pension Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	4,821	3,929
Level 1 | Pension Benefits | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Pension Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Pension Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	49
Level 1 | Pension Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Pension Benefits | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Pension Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	621	103
Level 1 | Pension Benefits | Receivable for variation margin
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	23	5
Level 1 | Pension Benefits | Investments sold short and other liabilities at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(450)	(513)
Level 1 | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	1,152	964
Level 1 | Postretirement Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	1,153	964
Level 1 | Postretirement Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	497	248
Level 1 | Postretirement Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	363	438
Level 1 | Postretirement Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	282	265
Level 1 | Postretirement Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	5	7
Level 1 | Postretirement Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	6	6
Level 1 | Postretirement Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Postretirement Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 1 | Postretirement Benefits | Securities lending payable and other liabilities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(1)	0
Level 2 | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	18,965	18,786
Level 2 | Pension Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	18,973	18,788
Level 2 | Pension Benefits | Non-interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Pension Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Pension Benefits | Foreign currency contracts
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	3	5
Level 2 | Pension Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Pension Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	11	11
Level 2 | Pension Benefits | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Pension Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	11,043	10,469
Level 2 | Pension Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	6,039	6,123
Level 2 | Pension Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	442	522
Level 2 | Pension Benefits | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Pension Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	1,435	1,658
Level 2 | Pension Benefits | Receivable for variation margin
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Pension Benefits | Investments sold short and other liabilities at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(8)	(2)
Level 2 | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	834	1,269
Level 2 | Postretirement Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	863	1,305
Level 2 | Postretirement Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	302	301
Level 2 | Postretirement Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Postretirement Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 2 | Postretirement Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	307	492
Level 2 | Postretirement Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	132	182
Level 2 | Postretirement Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	94	294
Level 2 | Postretirement Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	28	36
Level 2 | Postretirement Benefits | Securities lending payable and other liabilities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(29)	(36)
Level 3 | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	8,390	11,639	11,333
Level 3 | Pension Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	8,391	11,639
Level 3 | Pension Benefits | Non-interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Pension Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Pension Benefits | Foreign currency contracts
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Pension Benefits | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	5,793	8,816	8,750
Level 3 | Pension Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	11	4
Level 3 | Pension Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	12	6
Level 3 | Pension Benefits | Preferred interest
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	5,771	8,806
Level 3 | Pension Benefits | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	53	6	4
Level 3 | Pension Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	52	4
Level 3 | Pension Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Pension Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	1	2
Level 3 | Pension Benefits | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	2,544	2,817	2,579
Level 3 | Pension Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Pension Benefits | Receivable for variation margin
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Pension Benefits | Investments sold short and other liabilities at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	(1)	0
Level 3 | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	4	32	13
Level 3 | Postretirement Benefits | Assets at fair value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	4	32
Level 3 | Postretirement Benefits | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Postretirement Benefits | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0	1
Level 3 | Postretirement Benefits | Equity securities: Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Postretirement Benefits | Equity securities: International equities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Postretirement Benefits | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	4	32	12
Level 3 | Postretirement Benefits | Fixed income securities: Corporate bonds and other investments
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	3	31
Level 3 | Postretirement Benefits | Fixed income securities: Government and municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	1	1
Level 3 | Postretirement Benefits | Fixed income securities: Mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Postretirement Benefits | Real estate and real assets
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0	$ 0
Level 3 | Postretirement Benefits | Securities lending collateral
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Level 3 | Postretirement Benefits | Securities lending payable and other liabilities
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	0	0
Assets held at net asset value practical expedient | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	14,554	12,316
Assets held at net asset value practical expedient | Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Plan Net Assets	$ 1,889	$ 1,890

Pension And Postretirement B_12

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, 2020	Dec. 31, 2019
Pension Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	$ 53,530	$ 51,681
Fair value of plan assets at end of year	54,606	53,530
Pension Assets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	11,639	11,333
Realized gains (losses)	105	64
Unrealized gains (losses)	(175)	103
Transfers in	91	147
Transfers out	(3)	(6)
Purchases	9,338	235
Sales	(12,605)	(237)
Fair value of plan assets at end of year	8,390	11,639
Pension Assets | Equity securities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	8,816	8,750
Realized gains (losses)	(150)	0
Unrealized gains (losses)	3	58
Transfers in	4	8
Transfers out	0	0
Purchases	9,114	0
Sales	(11,994)	0
Fair value of plan assets at end of year	5,793	8,816
Pension Assets | Fixed Income Funds | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	6	4
Realized gains (losses)	0	0
Unrealized gains (losses)	0	0
Transfers in	51	5
Transfers out	(3)	(6)
Purchases	1	7
Sales	(2)	(4)
Fair value of plan assets at end of year	53	6
Pension Assets | Real Estate and Real Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	2,817
Fair value of plan assets at end of year	2,544	2,817
Pension Assets | Real Estate and Real Assets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	2,817	2,579
Realized gains (losses)	255	64
Unrealized gains (losses)	(178)	45
Transfers in	36	134
Transfers out	0	0
Purchases	223	228
Sales	(609)	(233)
Fair value of plan assets at end of year	2,544	2,817
Postretirement Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	4,145	4,277
Fair value of plan assets at end of year	3,843	4,145
Postretirement Assets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	32	13
Transfers in	3	28
Transfers out	(11)	(1)
Sales	(20)	(8)
Fair value of plan assets at end of year	4	32
Postretirement Assets | Equity securities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	0	1
Transfers in	0	0
Transfers out	0	0
Sales	0	(1)
Fair value of plan assets at end of year	0	0
Postretirement Assets | Fixed Income Funds | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	32	12
Transfers in	3	28
Transfers out	(11)	(1)
Sales	(20)	(7)
Fair value of plan assets at end of year	4	32
Postretirement Assets | Real Estate and Real Assets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Transfers in	0	0
Transfers out	0	0
Sales	0	0
Fair value of plan assets at end of year	$ 0	$ 0

Pension And Postretirement B_13

Pension And Postretirement Benefits (Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2020USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
2021	$ 5,391
2022	4,597
2023	4,428
2024	4,323
2025	4,234
Years 2026 - 2030	19,646
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
2021	1,392
2022	1,231
2023	1,159
2024	879
2025	832
Years 2026 - 2030	$ 3,651

Share-Based Payments (Narrative

Share-Based Payments (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of authorized shares of common stock for share-based payment arrangements (in shares)	183
Total unrecognized compensation cost related to nonvested share-based payment arrangements granted	$ 709
Weighted-average period to recognize the cost (years) - nonvested units	2 years 1 month 2 days
Total fair value of shares vested during the year - nonvested units	$ 647	$ 798	$ 766
Cash proceeds from exercise of stock options	$ 65	$ 446	$ 361
Restricted stock and stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Restricted stock and stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Restricted stock and stock units | Time Warner | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Restricted stock and stock units | Time Warner | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Stock options | Time Warner
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Other nonvested stock units
Share-based Compensation Arrangement by Share-based Payment Award [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, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	$ 638	$ 819	$ 463
Income tax benefit	157	202	114
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	348	544	301
Restricted stock and stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	290	273	153
Other nonvested stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	0	7	4
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	$ 0	$ (5)	$ 5

Share-Based Payments (Summary O

Share-Based Payments (Summary Of Nonvested Stock Units Activity) (Details) shares in Millions	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Shares
Nonvested at beginning of period (in shares) | shares	42
Granted (in shares) | shares	23
Vested (in shares) | shares	(18)
Forfeited (in shares) | shares	(4)
Nonvested at end of period (in shares) | shares	43
Weighted-Average Grant- Date Fair Value
Nonvested at beginning of period (in dollars per share) | $ / shares	$ 33.80
Granted (in dollars per share) | $ / shares	36.90
Vested (in dollars per share) | $ / shares	35.87
Forfeited (in dollars per share) | $ / shares	34.48
Nonvested at end of period (in dollars per share) | $ / shares	$ 34.50

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) $ / shares in Units, € / shares in Thousands, $ in Millions	Nov. 06, 2020USD ($)	Oct. 31, 2020USD ($)	Dec. 31, 2020USD ($)$ / sharesshares	Sep. 30, 2020USD ($)period	Dec. 31, 2019USD ($)$ / sharesshares	Sep. 30, 2019USD ($)	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)period$ / sharesshares	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2020€ / sharesshares
Class of Stock [Line Items]
Common stock, authorized (in shares) | shares			14,000,000,000		14,000,000,000		14,000,000,000	14,000,000,000		14,000,000,000
Preferred stock, authorized (in shares) | shares			10,000,000		10,000,000		10,000,000	10,000,000		10,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 1		$ 1		$ 1	$ 1
Preferred stock, par value (in dollars per share) | $ / shares			$ 1		$ 1		$ 1	1
Period post issuance date that preferred shares are optionally redeemable at liquidation price							5 years
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock (in shares) | shares							142,000,000
Amount repurchased							$ 5,278
Preferred stock, quarterly dividend declared			$ 36		$ 8
Common stock, quarterly dividend declared per common shares (in dollars per share) | $ / shares			$ 0.52		$ 0.52		$ 2.08	$ 2.05	$ 2.01
Noncontrolling Interest [Line Items]
Redemption of nonconvertible cumulative preferred interests in subsidiary							$ 1,950	$ 0	$ 0
Discontinued Operations, Disposed of by Sale | Puerto Rico And U.S. Virgin Islands Operations
Noncontrolling Interest [Line Items]
Redemption of nonconvertible cumulative preferred interests in subsidiary	$ 1,950	$ 1,950
Stock Repurchase Program, March 2013
Equity, Class of Treasury Stock [Line Items]
Shares authorized for repurchase (in shares) | shares			300,000,000				300,000,000			300,000,000
Stock Repurchase Program, March 2014
Equity, Class of Treasury Stock [Line Items]
Shares authorized for repurchase (in shares) | shares			300,000,000				300,000,000			300,000,000
Amount outstanding (in shares) | shares			178,000,000				178,000,000			178,000,000
Tower Holdings
Noncontrolling Interest [Line Items]
Preferred interest issued					$ 6,000			6,000
Fixed future purchase option price								$ 6,000
Distribution reset period								5 years
Period post issuance date that preferred interests can be called at issue price								5 years
Option to require redemption, certain contingent events, failure of subsidiary to pay preferred distributions, minimum number of periods | period								2
Telco LLC
Noncontrolling Interest [Line Items]
Preferred interest issued				$ 2,000
Initial preferred distribution percentage				4.25%
Distribution reset period				7 years
Period post issuance date that preferred interests can be called at issue price				7 years
Option to require redemption, certain contingent events, failure of subsidiary to pay preferred distributions, minimum number of periods | period				2
PR Holdings
Noncontrolling Interest [Line Items]
Preferred interest issued					$ 1,950			$ 1,950
Initial preferred distribution percentage								4.75%
Preferred Stock – Series A
Class of Stock [Line Items]
Preferred stock, outstanding (in shares) | shares			48,000		48,000		48,000	48,000		48,000
Preferred stock, liquidation preference per share (in dollars/Euros per share) | $ / shares			$ 25,000				$ 25,000
Preferred stock, dividend rate							5.00%
Preferred Stock – Series A | Mobility II, LLC
Noncontrolling Interest [Line Items]
Preferred interest, securities issued (in shares) | shares			320,000,000				320,000,000			320,000,000
Preferred interest distributions							$ 560
Put or redemption option, minimum exercise price calculation, value added to accrued and unpaid distributions (in dollars per share) | $ / shares							$ 25
Put or redemption option, minimum exercise price calculation, value added to accrued and unpaid distributions in the aggregate							$ 8,000
Maximum shares of common stock required to deliver to settle put and redemption options (in shares) | shares							250,000,000
Class A-1 | Tower Holdings
Noncontrolling Interest [Line Items]
Preferred interest issued						$ 1,500
Initial preferred distribution percentage						5.00%
Class A-2 | Tower Holdings
Noncontrolling Interest [Line Items]
Preferred interest issued					$ 4,500			$ 4,500
Initial preferred distribution percentage					4.75%
Preferred Stock – Series B
Class of Stock [Line Items]
Preferred stock, outstanding (in shares) | shares			20,000		0		20,000	0		20,000
Preferred stock, liquidation preference per share (in dollars/Euros per share) | € / shares										€ 100
Preferred stock, dividend rate							2.875%
Preferred Stock – Series C
Class of Stock [Line Items]
Preferred stock, outstanding (in shares) | shares			70,000		0		70,000	0		70,000
Preferred stock, liquidation preference per share (in dollars/Euros per share) | $ / shares			$ 25,000				$ 25,000
Preferred stock, dividend rate							4.75%

Sales Of Receivables (Equipment

Sales Of Receivables (Equipment Installment and AT&T Revolving Programs) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Equipment Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross receivables	$ 5,565	$ 4,576
Other Assets	2,295	1,632
Outstanding portfolio of receivables derecognized from our consolidated balance sheets	7,827	9,713
Cash proceeds received, net of remittances	5,646	7,211
Equipment Installment | Notes receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	2,716	2,467
Equipment Installment | Trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	554	477
Revolving
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross receivables	3,909	3,324
Other Assets	194	515
Outstanding portfolio of receivables derecognized from our consolidated balance sheets	5,300	4,300
Cash proceeds received, net of remittances	5,300	4,300
Revolving | Notes receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	0	0
Revolving | Trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 3,715	$ 2,809

Sales Of Receivables (Finance R

Sales Of Receivables (Finance Receivables) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net receivables sold	$ 15,760	$ 11,604	$ 0
Cash proceeds received	15,888	11,989	0
Guarantee obligation recorded	271	530	0
Equipment Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross receivables sold	7,270	9,921	9,391
Net receivables sold	7,026	9,483	8,871
Cash proceeds received	6,089	8,189	7,488
Deferred purchase price recorded	1,021	1,451	1,578
Guarantee obligation recorded	$ 157	$ 341	$ 361

Sales Of Receivables (Finance_2

Sales Of Receivables (Finance Receivables Repurchased) (Details) - Equipment Installment - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair value of repurchased receivables	$ 1,271	$ 1,418	$ 1,480
Carrying value of deferred purchase price	1,235	1,350	1,393
Gain on repurchases	$ 36	$ 68	$ 87

Sales Of Receivables (Equipme_2

Sales Of Receivables (Equipment Installment and AT&T Revolving Programs) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Equipment Installment Program | Guarantee Obligation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Guarantee obligation	$ 228	$ 384
Equipment Installment Program | Accounts payable and accrued liabilities | Guarantee Obligation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Guarantee obligation	161	148
Equipment Installment Program | Deferred Purchase Price Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred purchase price receivable	1,991	2,336
Equipment Installment Program | Deferred Purchase Price Receivables | Other current assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred purchase price receivable	1,476	$ 1,569
Revolving Receivables Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving agreement, term		1 year
Revolving agreement, transfer amount (up to)	$ 5,300	$ 4,300
Revolving agreement extension term	1 year
Receivables pledged as collateral	$ 3,909

Sales Of Receivables (Summary o

Sales Of Receivables (Summary of Receivables Sold) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Gross receivables sold/cash proceeds received	$ 15,888	$ 11,989	$ 0
Collections reinvested under revolving agreement	14,888	7,689	0
Net cash proceeds received (remitted)	1,000	4,300	0
Net receivables sold	15,760	11,604	0
Obligations recorded (reversed)	271	530	$ 0
Initial sale of receivables	$ 1,000	$ 4,300

Tower Transaction (Narrative) (

Tower Transaction (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)tower	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Other Liabilities [Line Items]
Balance of tower assets	$ 127,315	$ 130,128	$ 131,473
Depreciation expense	$ 20,277	20,285	20,083
Crown Castle International
Other Liabilities [Line Items]
Number of wireless towers with exclusive rights to lease | tower	9,048
Number of wireless towers subject to disposition | tower	627
Cash from failed sale-leaseback	$ 4,827
Term of lease	28 years
Approximate fixed future purchase option price on failed sale-leaseback	$ 4,200
Initial term	10 years
Balance of tower assets	$ 764	804
Depreciation expense	$ 39	$ 39	$ 39
Approximate annual interest rate - financing obligation	3.90%
Lease payments	$ 248
Minimum lease payments - 2021	253
Minimum lease payments - 2022	258
Minimum lease payments - 2023	264
Minimum lease payments - 2024	269
Minimum lease payments - 2025	274
Minimum lease payments - thereafter	$ 856

FirstNet (Narrative) (Details)

FirstNet (Narrative) (Details) - Licensing Agreements - FirstNet $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2017USD ($)milestone
Government Contracts Subject to Renegotiation [Line Items]
Term of contract		25 years
Amount of success-based payments expected to be received		$ 6,500
Period over which success-based payments are expected to be received, construction period		5 years
Sustainability payment commitment amount		$ 18,000
Amount estimated to be reinvested into the network		$ 15,000
Amount submitted in sustainability payments	$ 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 in 2025	195
Future sustainability payments due thereafter	16,620
Number of operating capability milestones | milestone		6
Refunds received under contract	$ 5,000
Expected refund collection period	2 years
Amount expected to receive for reinvestment above original success-based payments	$ 200
Maximum
Government Contracts Subject to Renegotiation [Line Items]
Anticipated amount of operating expenses over life of contract, adjusted for inflation (or less)		$ 3,000

Contingent Liabilities (Narrati

Contingent Liabilities (Narrative) (Details) $ in Millions	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Contractual purchase obligations for 2021	$ 20,274
Contractual purchase obligations for 2022 and 2023	21,275
Contractual purchase obligations for 2024 and 2025	11,142
Contractual purchase obligations for total years thereafter	$ 17,919

Additional Financial Informat_3

Additional Financial Information (Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts payable and accrued liabilities:
Accounts payable	$ 31,836	$ 29,640
Accrued payroll and commissions	2,988	3,126
Current portion of employee benefit obligation	1,415	1,528
Accrued participations and residuals	2,708	2,852
Accrued interest	2,454	2,498
Other	7,631	6,312
Total accounts payable and accrued liabilities	$ 49,032	$ 45,956

Additional Financial Informat_4

Additional Financial Information (Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Advertising expense	$ 5,253	$ 6,121	$ 5,100
Interest expense incurred	8,048	8,622	8,450
Capitalized interest	(123)	(200)	(493)
Total interest expense	$ 7,925	$ 8,422	$ 7,957

Additional Financial Informat_5

Additional Financial Information (Cash and Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents and Restricted Cash
Cash and cash equivalents	$ 9,740	$ 12,130	$ 5,204	$ 50,498
Restricted cash in Other current assets	9	69	61	6
Restricted cash in Other Assets	121	96	135	428
Cash and cash equivalents and restricted cash	$ 9,870	$ 12,295	$ 5,400	$ 50,932

Additional Financial Informat_6

Additional Financial Information (Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash paid (received) during the year for:
Interest	$ 8,237	$ 8,693	$ 8,818
Income taxes, net of refunds	993	1,421	(354)
Additional Financial Information [Line Items]
Spectrum acquisitions	1,851	1,809	43,309
Spectrum Licenses
Additional Financial Information [Line Items]
Spectrum acquisitions	$ 1,613	$ 1,576	$ 521

Additional Financial Informat_7

Additional Financial Information (Narrative) (Details) employee in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)employee	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Jan. 31, 2021employee
Additional Financial Information [Line Items]
Percentage of employees represented by CWA, IBEW, or other unions	37.00%
Subsequent Event
Additional Financial Information [Line Items]
Approximate number of persons employed at a point in time				230
Contract Covering Employees in 36 States and District of Columbia | Communications | Mobility
Additional Financial Information [Line Items]
Number of employees under contracts where union may call a work stoppage	14
Contract Covering Employees in 9 Southeast States | Communications | Mobility
Additional Financial Information [Line Items]
Number of employees under contracts where union may call a work stoppage	10
Vendor Financing Program
Additional Financial Information [Line Items]
Noncash investing activities | $	$ 4,664	$ 2,632	$ 2,162

Subsequent Events (Unaudited) (

Subsequent Events (Unaudited) (Details)	Mar. 10, 2021USD ($)	Feb. 24, 2021USD ($)license	Mar. 24, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2022USD ($)	Jun. 21, 2021USD ($)	Jun. 04, 2021USD ($)	May 17, 2021USD ($)	Dec. 31, 2019USD ($)
Subsequent Event [Line Items]
Assets				$ 525,761,000,000						$ 551,669,000,000
C-Band Licenses
Subsequent Event [Line Items]
Payments to acquire intangible assets				550,000,000
Video
Subsequent Event [Line Items]
Assets				16,150,000,000
Liabilities				$ 4,900,000,000
Subsequent Event | C-Band Licenses
Subsequent Event [Line Items]
Winning bidder, number of licenses | license		1,621
Estimated relocation costs		$ 3,400,000,000
Subsequent Event | Phase I Spectrum
Subsequent Event [Line Items]
Estimated Incentive Payments upon clearing of spectrum		955,000,000
Subsequent Event | Phase II Spectrum
Subsequent Event [Line Items]
Estimated Incentive Payments upon clearing of spectrum		$ 2,112,000,000
Subsequent Event | AT&T Inc | Sale of Business Unit | WarnerMedia
Subsequent Event [Line Items]
Disposal Group Proposed Merger Agreement Termination Fee [Line Items]							$ 1,770,000,000
Subsequent Event | Discovery, Inc. [Member] | Sale of Business Unit | WarnerMedia
Subsequent Event [Line Items]
Disposal Group Proposed Merger Agreement Termination Fee [Line Items]							720,000,000
Subsequent Event | DIRECTV (New DTV)
Subsequent Event [Line Items]
Amount funded by debt taken on by newly formed company					$ 5,800,000,000
Subsequent Event | Magallanes, Inc. (Spinco) [Member] | Credit agreement borrowings | Bridge Commitment Letter [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								$ 31,500,000,000	$ 41,500,000,000
Credit agreement - advances outstanding							0
Subsequent Event | Magallanes, Inc. (Spinco) [Member] | Credit agreement borrowings | June 2021 Term Loan [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								$ 10,000,000,000
Credit agreement - advances outstanding							$ 0
Subsequent Event | Forecast | C-Band Licenses
Subsequent Event [Line Items]
Payments to acquire intangible assets	$ 4,681,000,000		$ 18,725,000,000
Subsequent Event | Forecast | Sale of Business Unit | WarnerMedia
Subsequent Event [Line Items]
Cash proceeds received at closing						$ 43,000,000,000
Subsequent Event | Forecast | Sale of Business Unit | Video Business Unit
Subsequent Event [Line Items]
Cash proceeds received at closing					7,600,000,000
Subsequent Event | Forecast | AT&T Shareholders [Member] | Sale of Business Unit | WarnerMedia
Subsequent Event [Line Items]
Economic interest in common units						71.00%
Subsequent Event | Forecast | Discovery Shareholders [Member] | Sale of Business Unit | WarnerMedia
Subsequent Event [Line Items]
Economic interest in common units						29.00%
Subsequent Event | Forecast | DIRECTV (New DTV)
Subsequent Event [Line Items]
Interest in newly formed company, additional distribution preference					$ 4,200,000,000
Economic interest in common units held after disposal of business unit					70.00%
Agreement to pay net losses under NFL Sunday Ticket Contract, cap amount					$ 2,500,000,000
Subsequent Event | Forecast | DIRECTV (New DTV) | TPG Capital
Subsequent Event [Line Items]
Cash contribution to newly formed company					$ 1,800,000,000
Economic interest in common units					30.00%
Junior Preferred Interests | Subsequent Event | Forecast | DIRECTV (New DTV)
Subsequent Event [Line Items]
Preferred interest in newly formed company					$ 4,250,000,000
Senior Preferred Interests | Subsequent Event | Forecast | DIRECTV (New DTV) | TPG Capital
Subsequent Event [Line Items]
Preferred interest in newly formed company					$ 1,800,000,000