Frontier Communications Parent (FYBR) 10-K3 Mar 212020 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Document and Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-11001
Entity Registrant Name	FRONTIER COMMUNICATIONS CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-0619596
Entity Address, Address Line One	401 Merritt 7
Entity Address, City or Town	Norwalk
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06851
City Area Code	203
Local Phone Number	614-5600
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	true
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 10.5
Entity Common Stock, Shares Outstanding		104,779
Title of 12(g) Security	Common Stock, par value $0.25 per share
Documents Incorporated By Reference	DOCUMENT INCORPORATED BY REFERENCE Items 10, 11, 12, 13 and 14 of Part III will be incorporated by reference from a Form 10K/A to be filed with the Securities and Exchange Commission.
Amendment Flag	false
Document Fiscal Period Focus	FY
Entity Central Index Key	0000020520

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 1,829	$ 760
Accounts receivable, less allowances of $130 and $120, respectively	553	629
Contract acquisition costs	97	105
Prepaid expenses	90	89
Assets held for sale		1,401
Income taxes and other current assets	85	53
Total current assets	2,654	3,037
Property, plant and equipment, net	12,931	12,963
Other intangibles, net	677	1,020
Other assets	533	468
Total assets	16,795	17,488
Current liabilities:
Long-term debt due within one year	5,781	994
Accounts payable	540	437
Advanced billings	202	219
Accrued other taxes	204	206
Accrued interest	47	407
Pension and other postretirement benefits	48	43
Liabilities held for sale		123
Other current liabilities	318	375
Total current liabilities	7,140	2,804
Deferred income taxes	343	462
Pension and other postretirement benefits	2,195	1,896
Other liabilities	452	412
Long-term debt		16,308
Total liabilities not subject to compromise	10,130	21,882
Liabilities subject to compromise	11,565
Total liabilities	21,695	21,882
Equity (Deficit):
Common stock, $0.25 par value (175,000 authorized shares, 106,025 issued, and 104,793 and 105,131 outstanding, at December 31, 2020 and 2019, respectively)	27	27
Additional paid-in capital	4,817	4,815
Accumulated deficit	(8,975)	(8,573)
Accumulated other comprehensive loss, net of tax	(755)	(650)
Treasury common stock	(14)	(13)
Total equity (deficit)	(4,900)	(4,394)
Total liabilities and equity (deficit)	$ 16,795	$ 17,488

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Consolidated Balance Sheets [Abstract]
Allowances for accounts receivable, current	$ 130	$ 120
Common stock, par value (in dollars per share)	$ 0.25	$ 0.25
Common stock, shares authorized (in shares)	175,000,000	175,000,000
Common stock, shares outstanding (in shares)	104,793,000	105,131,000
Common stock, shares issued (in shares)	106,025,000	106,025,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements Of Operations [Abstract]
Revenue	$ 7,155	$ 8,107	$ 8,611
Operating expenses:
Network access expenses	975	1,247	1,441
Network related expenses	1,726	1,810	1,898
Selling, general and administrative expenses	1,648	1,804	1,815
Depreciation and amortization	1,598	1,780	1,954
Goodwill impairment		5,725	641
Loss on disposal of Northwest Operations	162	446
Restructuring costs and other charges	87	168	35
Total operating expenses	6,196	12,980	7,784
Operating income (loss)	959	(4,873)	827
Investment and other income (loss), net	(43)	(37)	13
Pension settlement costs	(159)	(57)	(41)
Gains (Loss) on early extinguishment of debt	(72)	(20)	32
Reorganization items, net	(409)
Interest expense (contractual interest for the year ended December 31, 2020 was $1,456 million)	(762)	(1,535)	(1,536)
Loss before income taxes	(486)	(6,522)	(705)
Income tax benefit	(84)	(611)	(62)
Net loss	(402)	(5,911)	(643)
Less: Dividends on preferred stock			107
Net loss attributable to Frontier common shareholders	$ (402)	$ (5,911)	$ (750)
Basic and diluted net loss per share attributable to Frontier common shareholders	$ (3.85)	$ (56.80)	$ (8.37)
Total weighted average shares outstanding - basic and diluted	104,467	104,065	89,683

Consolidated Statements Of Op_2

Consolidated Statements Of Operations (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Consolidated Statements Of Operations [Abstract]
Interest expense, contractual interest	$ 1,456

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Loss - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements Of Comprehensive Loss [Abstract]
Net loss	$ (402)	$ (5,911)	$ (643)
Other comprehensive loss, net of tax	(105)	(108)	(97)
Comprehensive loss	$ (507)	$ (6,019)	$ (740)

Consolidated Statements Of Equi

Consolidated Statements Of Equity (Deficit) - USD ($) shares in Thousands, $ in Millions	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]Revision of Prior Period, Accounting Standards Update, Adjustment [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Deficit [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Deficit [Member]Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Common Stock [Member]	Revision of Prior Period, Accounting Standards Update, Adjustment [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Total
Balance (Accounting Standards Update 2014-09 [Member]) at Dec. 31, 2017					$ 154							$ 154
Balance at Dec. 31, 2017		$ 20	$ 5,034				$ (2,263)		$ (366)	$ (151)			$ 2,274
Balance (in shares) at Dec. 31, 2017	19,250	79,532								(1,091)
Conversion of preferred stock, shares converted	(19,250)
Conversion of preferred stock, amount issued		$ 7	(7)
Conversion of preferred stock, shares issued		25,529
Stock plans			(118)							$ 137			19
Stock plans (in shares)		964								602
Dividends on preferred stock ($5.56 per share)			(107)										(107)
Net loss							(643)						(643)
Other comprehensive loss, net of tax									(97)				(97)
Balance (Accounting Standards Update 2014-09 [Member]) at Dec. 31, 2018				$ 11							$ 11
Balance (Accounting Standards Update 2018-02 [Member]) at Dec. 31, 2018						$ 79		$ (79)
Balance at Dec. 31, 2018		$ 27	4,802				(2,752)		(463)	$ (14)			1,600
Balance (in shares) at Dec. 31, 2018		106,025								(489)
Stock plans			13							$ 1			14
Stock plans (in shares)										(405)
Net loss							(5,911)						(5,911)
Other comprehensive loss, net of tax									(108)				(108)
Balance (Accounting Standards Update 2018-02 [Member]) at Dec. 31, 2019									(79)
Balance at Dec. 31, 2019		$ 27	4,815				(8,573)		(650)	$ (13)			(4,394)
Balance (in shares) at Dec. 31, 2019		106,025								(894)
Stock plans			2							$ (1)			1
Stock plans (in shares)										(338)
Net loss							(402)						(402)
Other comprehensive loss, net of tax									(105)				(105)
Balance at Dec. 31, 2020		$ 27	$ 4,817				$ (8,975)		$ (755)	$ (14)			$ (4,900)
Balance (in shares) at Dec. 31, 2020		106,025								(1,232)

Consolidated Statements Of Eq_2

Consolidated Statements Of Equity (Deficit) (Parenthetical)	12 Months Ended
Consolidated Statements Of Equity (Deficit) (Parenthetical)	Dec. 31, 2018$ / shares
Consolidated Statements Of Equity (Deficit) [Abstract]
Preferred stock, Cash dividends declared	$ 5.56

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows provided from (used by) operating activities:
Net loss	$ (402)	$ (5,911)	$ (643)
Adjustments to reconcile net loss to net cash provided from (used by) operating activities:
Depreciation and amortization	1,598	1,780	1,954
(Gain) Loss on early extinguishment of debt	72	20	(32)
Pension settlement costs	159	57	41
Pension/OPEB special termination benefit enhancements		44
Stock-based compensation expense	3	15	18
Amortization of deferred financing costs	15	30	34
Non-cash reorganization items	93
Other adjustments	6		(32)
Deferred income taxes	(91)	(619)	(67)
Goodwill impairment		5,725	641
Loss on disposal of Northwest Operations	162	446
Change in accounts receivable	73	48	65
Change in accounts payable and other liabilities	342	(122)	(141)
Change in prepaid expenses, income taxes and other assets	(41)	(5)	(26)
Net cash provided from operating activities	1,989	1,508	1,812
Cash flows provided from (used by) investing activities:
Capital expenditures - Business operations	(1,181)	(1,226)	(1,192)
Proceeds from sale of Northwest Operations	1,131
Proceeds on sale of assets	27	88	11
Other	4	4	5
Net cash used by investing activities	(19)	(1,134)	(1,176)
Cash flows provided from (used by) financing activities:
Long-term debt payments	(4,948)	(2,008)	(2,515)
Proceeds from long-term debt borrowings	4,950	1,650	1,840
Proceeds from revolving debt		949	525
Repayment of revolving debt	(749)	(475)	(250)
Financing costs paid	(121)	(44)	(43)
Dividends paid on preferred stock			(107)
Premium paid to retire debt			(17)
Finance lease obligation payments	(23)	(35)	(36)
Other	(2)	(5)	(5)
Net cash provided from (used by) financing activities	(893)	32	(608)
Increase (Decrease) in cash, cash equivalents and restricted cash	1,077	406	28
Cash, cash equivalents and restricted cash at January 1,	810	404	376
Cash, cash equivalents and restricted cash at December 31,	1,887	810	404
Cash paid (received) during the period for:
Interest	612	1,469	1,507
Income tax payments, net	8	4	4
Reorganization items, net	270
Non-cash investing and financing activities:
Financing obligation for contributions of real property to pension plan			37
Reduction of pension obligation			$ 37
Increase (Decrease) in capital expenditures due to changes in accounts payable	$ (117)	$ 13

Description Of Business And Sum

Description Of Business And Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Description Of Business And Summary Of Significant Accounting Policies [Abstract]
Description Of Business And Summary Of Significant Accounting Policies	(1) Description of Business and Summary of Significant Accounting Policies : (a) Description of Business : Frontier Communications Corporation (Frontier) is a provider of communications services in the United States, with approximately 3.6 million customers, 3.1 million broadband subscribers and 16,200 employees, operating in 25 states. Frontier was incorporated in 1935, originally under the name of Citizens Utilities Company and was known as Citizens Communications Company until July 31, 2008. Frontier and its subsidiaries are referred to as “we,” “us,” “our,” “Frontier,” or the “Company” in this report. (b) Basis of Presentation and Use of Estimates : Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Certain reclassifications of amounts previously reported have been made to conform to the current presentation. All significant intercompany balances and transactions have been eliminated in consolidation. For our financial statements as of and for the period ended December 31 , 2020, we evaluated subsequent events and transactions for potential recognition or disclosure through the date that we filed this Form 10-K with the Securities and Exchange Commission (SEC). The preparation of our financial statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities at the date of the financial statements, (ii) the disclosure of contingent assets and liabilities, and (iii) the reported amounts of revenue and expenses during the reporting period. Actual results may differ from those estimates. Estimates and judgments are used when accounting for the allowance for doubtful accounts, asset impairments, indefinite-lived intangibles, depreciation and amortization, income taxes, business combinations, and pension and other postretirement benefits, among others. (c) Going Concern : In connection with the preparation of our consolidated financial statements, we conducted an evaluation as to whether there were conditions and events, considered in the aggregate, which raised substantial doubt as to the entity’s ability to continue as a going concern within one year after the date of the issuance of our consolidated financial statements. Our consolidated financial statements have been prepared assuming that we will continue as a going concern, which contemplates continuity of operations, realization of assets, and satisfaction of liabilities in the normal course of business. On April 14, 2020 (the Petition Date), Frontier Communications Corporation and its subsidiaries (collectively, the Company Parties or the Debtors and, as they may be reorganized pursuant to the Plan, the Reorganized Company Parties or the Reorganized Debtors) commenced cases under chapter 11 (the Chapter 11 Cases) of title 11 of the United States Code (the Bankruptcy Code) in the U.S. Bankruptcy Court for the Southern District of New York (the Bankruptcy Court). On May 15, 2020, the Company Parties filed a proposed Joint Plan of Reorganization and related Disclosure Statement, each of which were amended on June 26, 2020, June 29, 2020 and June 30, 2020. On May 15, 2020, the Debtors also filed a proposed order approving the Disclosure Statement and various plan solicitation materials, including the solicitation and voting procedures, which was revised on June 29, 2020 (including modifications to some of the exhibits). On June 30, 2020, the Bankruptcy Court entered the modified order approving the adequacy of the Disclosure Statement and the solicitation and notice procedures and the forms of voting ballots and notices in connection therewith. The order established June 29, 2020 as the voting record date, July 2, 2020 as the solicitation launch date and July 31, 2020 as the voting deadline. On August 21, 2020, the Company Parties filed the Fifth Amended Joint Plan of Reorganization of Frontier Communications Corporation and Its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code (the Plan) with the Bankruptcy Court. On August 27, 2020, the Bankruptcy Court entered the Order Confirming the Fifth Amended Joint Plan of Reorganization of Frontier Communications Corporation and its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code (the Confirmation Order), which approved and confirmed the Plan. The effective date of the Plan will occur once all conditions precedent to the Plan have been satisfied (the Effective Date). Our ability to continue as a going concern is contingent upon, among other things, our ability to, subject to the Bankruptcy Court’s approval, implement the Plan, successfully emerge from the Chapter 11 Cases and generate sufficient liquidity from the Restructuring to meet our obligations and operating needs. As a result of risks and uncertainties related to (i) the Company’s ability to successfully consummate the Plan and emerge from the Chapter 11 Cases, and (ii) the effects of disruption from the Chapter 11 Cases making it more difficult to maintain business, financing and operational relationships, together with the Company’s recurring losses from operations and accumulated deficit, substantial doubt exists regarding our ability to continue as a going concern. For detailed discussion about the Chapter 11 Cases and the Plan, refer to Note 3. Our consolidated financial statements do not include any adjustments related to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might be necessary should we be unable to continue as a going concern. The filing of the Chapter 11 Cases constituted an event of default that accelerated substantially all of our obligations under the JPM Credit Agreement (as defined herein), the Company’s 8.000 % first lien secured notes due April 1, 2027 (the Original First Lien Notes), the Company’s 8.500 % second lien secured notes due April 1, 2026 (the Original Second Lien Notes), our unsecured notes and debentures and the secured and unsecured debentures of our subsidiaries. As of December 31, 2020, amounts that were outstanding under the JPM Credit Agreement, our Original First Lien Notes, and our Original Second Lien Notes have been repaid in full. We have reclassified our unsecured notes and debentures and the secured and unsecured debentures of our subsidiaries to “Long term debt due within one year” or “Liabilities Subject to Compromise”, based on the event of default or reinstatement provisions of each security in the Restructuring Support Agreement, on our consolidated balance sheet as of December 31, 2020. For additional discussion related to our debt obligations, and details of our refinancing of our secured debt, refer to Note 9. (d) Impact of COVID-19: On March 11, 2020, the World Health Organization declared the highly contagious and lethal corona virus outbreak a global pandemic (COVID-19) and recommended containment and other mitigation measures worldwide to lessen the transmission of COVID-19. In the first half of 2020, governments from around the world, including the United States federal government as well as state and local governments reacted to this public health crisis, imposing travel restrictions and restrictions on large gatherings of people, which includes school and non-essential business closures. The rapid spread of COVID-19 and the drastic responses being taken to curb its spread have resulted in a significant negative impact to the global and domestic economies, which will increase the longer these limitations are in place. In an effort to reduce the economic impacts of COVID-19, the United States federal government has responded with multiple stimulus bills, including the Coronavirus Aid, Relief, and Economic Security (CARES) Act, the largest economic stimulus legislation in American history. Despite these efforts, the short-term and long-term impacts of COVID-19 cannot be determined. With more people staying at home and an increased reliance on broadband and telephone networks, the Federal Communications Commission (FCC) issued the Keep Americans Connected Pledge on March 11, 2020, which provided for telecommunication providers, including Frontier, to not terminate service and to waive any late payment fees through June 30, 2020 for certain customers due to economic circumstances they are facing related to COVID-19 as well as making WIFI hotspots available to all Americans who need them. In addition, some of the states we operate in have issued executive orders as a result of COVID-19 that further impact our business, including prohibiting the disconnection of services for customers for the length of the state of emergency. While the initial 60-day period of the Keep Americans Connected Pledge has expired, state and federal governments continue to ask companies to aid in pandemic response. While certain customers have taken advantage of our COVID-19 related relief programs, as of December 31, 2020, very few had past due balances beyond the point of normal disconnection. In addition to committing to the Keep Americans Connected Pledge, Frontier’s response to COVID-19 has included several operational safety precautions such as limiting our product offerings in certain markets for certain periods, including not allowing our field service employees to enter a customer’s home for a period of time, a limitation which is no longer in effect. We are continuing to require personal protective equipment on any employees entering a customer location. The percentage of Frontier’s employees who have reported testing positive for COVID-19 is small and continues to track below the percentage of reported cases both nationally and in those states in which Frontier has a significant number of employees. Through December 31, 2020, we had not experienced any significant disruptions in our supply chain; however, some of our business partners, particularly those vendors operating outside of the United States, have been more greatly impacted which has affected our service levels and distribution of work. As the COVID-19 pandemic continues, certain states are currently considering legislation or other regulations to adopt additional protections for workers impacted by COVID-19. To date, we have not experienced significant disruptions in our workforce due to COVID-19 related absences or legislative or regulatory changes. Given the unprecedented and evolving nature of the pandemic and the swift moving response of multiple levels of government as well as the uncertainty of funding available for services provided, the full impact of these changes and potential changes on the Company are unknown at this time. While overall the operational and financial impacts to Frontier of the COVID-19 pandemic for the year ended December 31, 2020 were not significant, we continue to closely monitor the ongoing impact to our employees, our customers, our business and our results of operations. We have experienced a slowdown in service activations and an increase in deactivations for our SMB customers; to date, these negative impacts have been partially offset by higher residential activations and lower churn. We also continue to closely track our customers’ payment activity as well as external factors, including the expiration of federal wage subsidies for individuals and small businesses which could materially impact payment trends. With more people working from home, we have experienced higher demands on our network and higher sales activity for our residential broadband service offering. This sustained increase in network demand could lead to reduced network availability and potential outages, which may impair our ability to meet customer service level commitments, lead to higher costs, higher customer churn and potential increased regulatory actions. These potential changes, among others, could have a material financial impact to Frontier. (e) Debtor-In-Possession: In general, as debtors-in-possession under the Bankruptcy Code, we are authorized to continue to operate as an ongoing business but may not engage in transactions outside the ordinary course of business without the prior approval of the Bankruptcy Court. Pursuant to certain motions and applications intended to limit the disruption of the bankruptcy proceedings on our operations (the First Day Motions) and other motions filed with the Bankruptcy Court, the Bankruptcy Court has authorized us to conduct our business activities in the ordinary course, including, among other things and subject to the terms and conditions of such orders, authorizing us to obtain DIP financing, pay employee wages and benefits, settle certain de minimis disputes and pay vendors and suppliers in the ordinary course for all goods and services. (f) Cash Equivalents: We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents. Restricted cash of $ 58 million and $ 50 million is included within “other assets” on our consolidated balance sheet as of December 31, 2020 and 2019, respectively. These amounts represent Letters of Credit Obligations and utility adequate assurance account that is required under bankruptcy rules . (g) Revenue Recognition : Revenue for data & Internet services, voice services, video services and switched and non-switched access services is recognized as the individual performances obligations to the customer are satisfied. Services that are billed in advance include monthly recurring network access services (including data services), special access services, and monthly recurring voice, video, and related charges. Revenue is recognized as services are provided by measuring progress toward the complete satisfaction of the Company’s performance obligations. Progress is measured monthly based on months completed as a portion of the total contract. The unearned portion of these fees is initially deferred as a component of “Advanced billings” on our consolidated balance sheet and recognized as revenue over the period that the services are provided. Services that are billed in arrears include non-recurring network access services (including data services), switched access services, and non-recurring voice and video services. The earned but unbilled portion of these fees is recognized as revenue in our consolidated statements of operations and accrued in “Accounts receivable” on our consolidated balance sheet in the period that services are provided. Excise taxes are recognized as a liability when billed. Satisfaction of Performance Obligations Frontier satisfies its obligations to customers by transferring goods and services in exchange for consideration received from the customer. The timing of Frontier’s satisfaction of the performance obligation often differs from the timing of the customer’s payment, which results in the recognition of a contract asset or a contract liability. Frontier recognizes a contract asset or liability when the Company transfers goods or services to a customer and bills an amount which differs from the revenue allocated to the related performance obligations. Bundled Service and Allocation of Discounts When customers purchase more than one service, the revenue allocable to each service is determined based upon the relative stand-alone selling price of each service received. We frequently offer service discounts as an incentive to customers. Service discounts reduce the total transaction price allocated to the performance obligations that are satisfied over the term of the customer contract. We may also offer incentives which are considered cash equivalents (e.g. Visa gift cards) that similarly result in a reduction of the total transaction price as well as lower revenue over the term of the contract. A contract asset is often created during the beginning of the contract term when the term of the incentive is shorter than the contract term. These contract assets are realized over the term of the contract as our performance obligations are satisfied and customer consideration is received. Customer Incentives In the process of acquiring and/or retaining customers, we may issue a variety of other incentives aside from service discounts or cash equivalent incentives. Those incentives that have stand-alone value (e.g. gift cards not considered cash equivalents or free goods/services) are considered a separate performance obligation. As a result, while these incentives are free to the customer, a portion of the consideration received from the customer over the contract term is ascribed to them based upon their relative stand-alone selling price. The revenue, reflected in “Other” revenue, and costs, reflected in “Network access expenses”, for these incentives are recognized when they are delivered to the customer and the performance obligation is satisfied. Similar to discounts, these types of incentives generally result in the creation of a contract asset during the beginning of the contract term which is recorded in Other current assets and Other assets on our consolidated balance sheet. Upfront Fees All non-refundable upfront fees provide our customers with a material right to renew, and therefore, are deferred and amortized into revenue over the expected period for which related services are provided. With upfront fees assessed at the beginning of a contract, a contract liability is often created, which is reduced over the term of the contract as the performance obligations are satisfied. The contract liabilities are recorded in Other current liabilities and Other liabilities on our consolidated balance sheet. Contributions in Aid of Construction (CIAC) It is customary for us to charge customers for certain construction activities. These activities are requested by the customer and construction charges are assessed at the beginning of a contract. When charges are incurred, a contract liability is often created, which is reduced over the term of the contract as performance obligations are satisfied. The contract liabilities are recorded in Other current liabilities and Other liabilities on our consolidated balance sheet. Contract Acquisition Costs Certain costs to acquire customers are deferred and amortized over the expected customer life (average of 4.0 years). For Frontier, this includes certain commissions paid to acquire new customers. Commissions attributable to new customer contracts are deferred and amortized into expense. Unamortized deferred commissions are recorded in Contract acquisition costs and Other assets on our consolidated balance sheet. Surcharges and Subsidies Frontier collects various taxes from its customers and subsequently remits these taxes to governmental authorities. Substantially all of these taxes are recorded through the consolidated balance sheet and presented on a net basis in our consolidated statements of operations. We also collect Universal Service Fund (USF) surcharges from customers (primarily federal USF), of $ 193 million, $ 221 million, and $ 213 million for the years ended December 31, 2020, 2019 and 2018, respectively, and video franchise fees of $ 30 million, $ 40 million, and $ 47 million for the years ended December 31, 2020, 2019, and 2018, respectively, that we have recorded on a gross basis in our consolidated statements of operations and included within “Revenue” and “Network related expenses. We accepted the FCC’s Connect America Fund (CAF) Phase II and RDOF offers of support, which are intended to provide long-term support for broadband in high cost unserved or underserved areas. We are recognizing these FCC subsidies into revenue on a straight-line basis over the seven year funding term for CAF Phase II and the ten year funding term for RDOF. (h) Property, Plant and Equipment : Property, plant and equipment are stated at original cost, including capitalized interest, or fair market value as of the date of acquisition for acquired properties. Maintenance and repairs are charged to operating expenses as incurred. The gross book value of routine property, plant and equipment retirements is charged against accumulated depreciation (i) Definite and Indefinite Lived Intangible Assets: Intangible assets arising from business combinations, such as customer lists, royalty agreements, and tradenames, are initially recorded at estimated fair value . Frontier amortizes its customer list and certain other finite-lived intangible assets over their estimated useful lives on the accelerated method of sum of the years’ digits and its royalty agreement over its estimated useful life on the straight-line method. Definite lived and Indefinite lived intangible assets are assessed for impairment annually, as of December 31, or more frequently, if events or changes in circumstances indicate the estimated fair value may be less than the carrying amount. Additionally, Frontier reviews whether factors exist that would necessitate a change in useful life and a different amortization period. (j) Impairment of Long-Lived Assets and Long-Lived Assets to Be Disposed Of : We review long-lived assets to be held and used, including customer lists and property, plant and equipment, and long-lived assets to be disposed of for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by comparing the carrying amount of the asset to the future undiscounted net cash flows expected to be generated by the asset. Recoverability of assets held for sale is measured by comparing the carrying amount of the assets to their estimated fair market value. If any assets are considered to be impaired, the impairment is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value. Also, we periodically reassess the useful lives of our long-lived assets to determine whether any changes are required. (k) Lease Accounting: We determine if an arrangement contains a lease at inception. Right-of-use (ROU) assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating and Finance lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating and finance lease ROU asset also includes any lease payments made and excludes lease incentives. Our lease terms used in accounting for leases may reflect options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for operating leases is recognized on a straight-line basis over the lease term. ROU assets for operating leases are recorded to “Other Assets”, and the related liabilities recorded to “Other current liabilities”, and “Other liabilities” on our consolidated balance sheets. Assets subject to finance leases are included in “Property, Plant & Equipment”, with corresponding liabilities recorded to “Other current liabilities”, and “Other liabilities” on our consolidated balance sheets. (l) Income Taxes and Deferred Income Taxes : We file a consolidated federal income tax return. We utilize the asset and liability method of accounting for income taxes. Under the asset and liability method, deferred income taxes are recorded for the tax effect of temporary differences between the financial statement basis and the tax basis of assets and liabilities using tax rates expected to be in effect when the temporary differences are expected to reverse. We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If we determine that we are not able to realize a portion of our net deferred tax assets in the future, we would make an adjustment to the deferred tax asset valuation allowance, which would increase the provision for income taxes. The tax effect of a change in tax law or rates included in income tax expense from continuing operations includes effect of changes in deferred tax assets and liabilities initially recognized through a charge or credit to other comprehensive income (loss). The residual tax effects typically are released when the item giving rise to the tax effect is disposed of, liquidated, or terminated. Since the Company has adopted the portfolio approach to release the residual tax effects, there is no release for the residual tax effect from the sale of our Northwest Operations. (m) Stock Plans : We have various stock-based compensation plans. Awards under these plans are granted to eligible employees and directors. Awards may be made in the form of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units or other stock-based awards, including awards with performance, market and time-vesting conditions. Our general policy is to issue shares from treasury upon the grant of restricted shares, earning of performance shares and the exercise of options. The compensation cost recognized is based on awards ultimately expected to vest. GAAP requires forfeitures to be estimated and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. (n) Net Loss Per Share Attributable to Frontier Common Shareholders : Basic net loss per common share is computed using the weighted average number of common shares outstanding during the period being reported on, excluding unvested restricted stock awards. The impact of dividends paid on unvested restricted stock awards have been deducted in the determination of basic and diluted net income (loss) per share attributable to Frontier common shareholders. Except when the effect would be antidilutive, diluted net income per common share reflects the dilutive effect of certain common stock equivalents, as described further in Note 16 – Net Loss Per Common Share. (o) Assets Held for Sale: We classify assets and related liabilities as held for sale when the following criteria are met: when management has committed to a plan to sell the asset, the asset is available for immediate sale, there is an active program to locate a buyer and the sale and transfer of the asset is probable within one year. Assets and liabilities are presented separately on the Consolidated Balance Sheets with a valuation allowance, if necessary, to recognize the net carrying amount at the lower of cost or fair value, less costs to sell. Depreciation and amortization for property, plant and equipment and finite-lived intangible assets, are not recorded while these assets are classified as held for sale. Assets held for sale are tested for recoverability each period that they are classified as held for sale. On May 1, 2020, Frontier completed the sale of its operations and associated assets in Washington, Oregon, Idaho, and Montana (Northwest Operations or Northwest Ops). As of December 31, 2019, the assets and liabilities of the Northwest Operations were classified as held for sale on our consolidated balance sheets, and the amounts and information of the Company in the footnotes as they are presented do not include assets and liabilities that have been reclassified, refer to Note 8.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
Recent Accounting Pronouncements	Dec. 31, 2020
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	(2) Recent Accounting Pronouncements : Recently Adopted Accounting Pronouncements Changes to the Disclosure Requirements for Defined Benefit Plans In August 2018, the FASB issued ASU 2018-14, “Compensation-Retirement Benefits-Defined Benefit Plans-General: Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans”. This standard eliminates requirements for certain disclosures that are not considered cost beneficial, clarifies certain required disclosures and adds additional disclosures under defined benefit pension plans and other postretirement plans. The amendments in the standard were early-adopted, as permitted, and the Company applied on a retrospective basis effective January 1, 2020. Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement,” which adds, removes, and modifies certain disclosures required by ASC 820. ASU 2018-13 is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Frontier adopted this standard effective January 1, 2020. New disclosures related to this standard have been included in Note 21 related to our Level 3 assets. Simplifying the Accounting for Income Taxes In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” This standard simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. Early adoption is permitted. Frontier early-adopted this standard on January 1, 2020, with no impact on our consolidated financial statements. Codification Improvements to Financial Instruments In March 2020, the FASB issued ASU 2020-03, “Codification Improvements to Financial Instruments.” This standard included various clarifications and improvements related to financial instruments including the modification of required disclosures for assets measured using the net asset value. These changes were effective upon the final issuance of the standard and have been applied to our fair value disclosures included in Note 21. Recent Accounting Pronouncements Not Yet Adopted Financial Instrument Credit Losses In June 2016, The FASB issued ASU 2016-13, “Financial Instruments – Credit Losses”. This standard, along with its amendments, update the current financial statement impairment model requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables. ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, with early adoption permitted. Frontier is currently evaluating the impact of adopting this standard on our consolidated financial statements. Reference Rate Reform In March 2020, the FASB issued ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting”. This standard 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. The standard applies to contracts and other arrangements that reference the London Interbank Offering Rate (LIBOR) or any other rates ending after December 31, 2022. Frontier is evaluating the impact of the adoption of this standard, including optional expedients, on our consolidated financial statements.

Chapter 11 Filing And Other Rel

Chapter 11 Filing And Other Related Matters	12 Months Ended
Chapter 11 Filing And Other Related Matters	Dec. 31, 2020
Chapter 11 Filing And Other Related Matters [Abstract]
Chapter 11 Filing And Other Related Matters	(3) Chapter 11 Filing and Other Related Matters: Filing of Chapter 11 Bankruptcy On April 14, 2020, the Company Parties entered into a Restructuring Support Agreement (the Restructuring Support Agreement) with certain of its noteholders (the Consenting Noteholders). The Restructuring Support Agreement contemplates agreed-upon terms for a pre-arranged financial restructuring plan that leaves unimpaired all general unsecured creditors and holders of secured debt and subsidiary debt. Under the Restructuring Support Agreement, the Consenting Noteholders agreed, subject to certain terms and conditions, to support a financial restructuring (the Restructuring) of the existing debt of, existing equity interests in, and certain other obligations of the Company Parties, pursuant to the Plan to be filed in the Chapter 11 Cases. To implement the Plan, on the Petition Date, the Company Parties filed the Chapter 11 Cases. Each Company Party continues to operate its business as a “debtor in possession” under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of the Bankruptcy Code and the orders of the Bankruptcy Court. The Chapter 11 Cases are being jointly administered under the caption In re Frontier Communications Corporation., et al., Case No. 20-22476 (RDD) . On May 15, 2020, the Company Parties filed a proposed Joint Plan of Reorganization and related Disclosure Statement, each of which were amended on June 26, 2020, June 29, 2020 and June 30, 2020. On May 15, 2020, the Debtors also filed a proposed order approving the Disclosure Statement and various plan solicitation materials, including the solicitation and voting procedures, which was revised on June 29, 2020 (including modifications to some of the exhibits). On June 30, 2020, the Bankruptcy Court entered the modified order approving the adequacy of the Disclosure Statement and the solicitation and notice procedures and the forms of voting ballots and notices in connection therewith. The order established June 29, 2020 as the voting record date, July 2, 2020 as the solicitation launch date and July 31, 2020 as the voting deadline. On August 21, 2020, the Company Parties filed the Fifth Amended Joint Plan of Reorganization of Frontier Communications Corporation and Its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code (the Plan) with the Bankruptcy Court. On August 27, 2020, the Bankruptcy Court entered the Order Confirming the Fifth Amended Joint Plan of Reorganization of Frontier Communications Corporation and its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code (the Confirmation Order), which approved and confirmed the Plan. The effective date of the Plan will occur once all conditions precedent to the Plan have been satisfied (the Effective Date). Restructuring Support Agreement On April 14, 2020, the Company Parties entered into the Restructuring Support Agreement with the Consenting Noteholders, pursuant to which the Consenting Noteholders agreed, subject to certain terms and conditions, to support the Restructuring of the existing debt of, existing equity interests in, and certain other obligations of the Company Parties, pursuant to a pre-arranged Plan to be filed in the Chapter 11 Cases. In accordance with the Restructuring Support Agreement, the Consenting Noteholders agreed, among other things, to: i) support the transactions (the Restructuring Transactions) described in, within the timeframes outlined in, and in accordance with the Restructuring Support Agreement; ii) not take any action, directly or indirectly, that is reasonably likely to interfere with acceptance, implementation, or consummation of the Restructuring Transactions; iii) vote each of its Senior Notes Claims (as defined in the Restructuring Support Agreement) to accept the Plan; and; iv) not transfer Senior Notes Claims held by each Consenting Noteholders except with respect to limited and customary exceptions, including requiring any transferee to either already be bound or become bound by the terms of the Restructuring Support Agreement. In accordance with the Restructuring Support Agreement, the Company Parties agreed, among other things, to: i) support and take all steps reasonably necessary and desirable to consummate the Restructuring Transactions in accordance with the Restructuring Support Agreement; ii) support and take all steps reasonably necessary and desirable to obtain entry of (a) the final orders of the Bankruptcy Court authorizing the relevant Company Parties’ entry into the documents governing a senior secured superpriority DIP financing facility, (b) the order of the Bankruptcy Court approving the disclosure statement related to the Plan pursuant to section 1125 of the Bankruptcy Code and (c) the Bankruptcy Court’s order confirming the Plan; iii) use commercially reasonable efforts to obtain any and all required governmental, regulatory, and/or third-party approvals for the Restructuring Transactions; iv) act in good faith and use commercially reasonable efforts to execute and deliver certain required documents and agreements to effectuate and consummate the Restructuring Transactions as contemplated by the Restructuring Support Agreement; v) operate their businesses in the ordinary course of business in a manner consistent with the Restructuring Support Agreement and past practice and use commercially reasonable efforts to preserve their businesses; and; vi) not, directly or indirectly, object to, delay, impede, or take any other action to interfere with acceptance, implementation, or consummation of the Restructuring Transactions. The Restructuring Support Agreement may be terminated upon the occurrence of certain events, including the failure to meet specified milestones related to consummation of the Plan. In addition, the Restructuring Support Agreement shall automatically terminate on the Effective Date of the Plan once all conditions precedent to the Plan have been satisfied. Chapter 11 Cases As an initial step towards implementation of the Plan, on the Petition Date, the Company Parties filed the Chapter 11 Cases. Each Company Party continues to operate its business as a “debtor in possession” under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of the Bankruptcy Code and the orders of the Bankruptcy Court. The Chapter 11 Cases are being jointly administered under the caption In re Frontier Communications Corporation., et al., Case No. 20-22476 (RDD). In general, as debtors-in-possession under the Bankruptcy Code, we are authorized to continue to operate as an ongoing business, however, we may not engage in transactions outside the ordinary course of business without the prior approval of the Bankruptcy Court. To that end, on the Petition Date, the Company Parties filed the First Day Motions, which were approved after a final hearing held on May 22, 2020. Pursuant to the First Day Motions, the Bankruptcy Court authorized us to conduct our business activities in the ordinary course, including, among other things and subject to the terms and conditions of such orders: continue to operate our cash management system and honor certain prepetition obligations related thereto; maintain existing business forms; continue to perform intercompany transactions; obtain super priority administrative expense status for post-petition intercompany balances; pay certain prepetition claims of critical vendors, lien claimants and section 503(b)(9) of the Bankruptcy Code claimants in the ordinary course of business on a post-petition basis; pay prepetition employee wages, salaries, other compensation and reimbursable employee expenses and continue employee benefits programs; pay obligations under prepetition insurance policies, continue to pay certain brokerage fees; renew, supplement, modify or purchase insurance coverage; maintain our surety bond program; pay certain prepetition taxes and fees; honor certain prepetition obligations to customers and continue certain customer programs in the ordinary course of business; and pay or honor prepetition claims of content providers. Plan and Disclosure Statement On May 15, 2020, the Company Parties filed a proposed Joint Plan of Reorganization and related Disclosure Statement, each of which were amended on June 26, 2020, June 29, 2020 and June 30, 2020. On May 15, 2020, the Debtors also filed a proposed order approving the Disclosure Statement and various plan solicitation materials, including the solicitation and voting procedures, which was revised on June 29, 2020 (including modifications to some of the exhibits) . On June 30, 2020, the Bankruptcy Court entered the modified order approving the adequacy of the Disclosure Statement and the solicitation and notice procedures and the forms of voting ballots and notices in connection therewith. The order established June 29, 2020 as the voting record date, July 2, 2020 as the solicitation launch date and July 31, 2020 as the voting deadline. On August 21, 2020, the Company Parties filed the Plan with the Bankruptcy Court. On August 27, 2020, the Bankruptcy Court entered the Confirmation Order, which approved and confirmed the Plan. The Effective Date of the Plan will occur once all conditions precedent to the Plan have been satisfied. The Plan as approved and confirmed by the Bankruptcy Court provides for:  the applicable (x) Debtors, with the consent of the Consenting Noteholders then holding greater than 50.1 % of the aggregate outstanding principal amount of senior notes claims that are held by all Consenting Noteholders subject to the Restructuring Support Agreement as of such date (the Required Consenting Noteholders), or (y) Reorganized Debtors taking any action as may be necessary or advisable to effectuate the restructuring transactions described in the Plan and Restructuring Transactions Memorandum (as defined in the Plan), including;  the execution, delivery, and filing of any organizational and governance documents for the Reorganized Company Parties;  any and all actions necessary or appropriate to effectuate the Secured Creditor Settlement (as defined below); and  the execution, delivery, and filing of all agreements, indentures, notes, filings, documents, and instruments delivered or entered into in connection with one or more DIP financing facilities, which shall be used to repay certain of the Company Parties’ prepetition secured indebtedness and shall convert into an exit facility on the Effective Date (a DIP-to-Exit Facility), and a DIP revolving financing facility, which shall, subject to certain conditions, convert into an exit revolving facility (a DIP-to-Exit Revolving Facility and, together with a DIP-to-Exit Facility, DIP Facilities);  the final satisfaction, compromise, settlement, release, and discharge of claims arising under, derived from, secured by, based on, or related to any DIP-to-Exit Facility documents or DIP-to-Exit Revolving Facility documents, on the Effective Date in exchange for payment in full in cash or, at the Company Parties’ election, and solely to the extent permitted under DIP-to-Exit Facility documents or DIP-to-Exit Revolving Facility documents, as applicable, or as otherwise agreed, such holder’s pro rata share of the applicable exit facilities;  on the Effective Date, issuance of takeback debt by one or more of the Reorganized Company Parties (the Takeback Debt), in a principal amount of $ 750 million, which shall include the following terms (which may be modified subject to requisite consent under the Plan):  an interest rate that is either (a) no more than 2.50 % higher than the interest rate of the next most junior secured debt facility to be entered into on the Effective Date if the Takeback Debt is secured on a third lien basis or (b) no more than 3.50 % higher than the interest rate of the most junior secured debt facility to be entered into on the Effective Date if the Takeback Debt is unsecured;  a maturity of no less than one year outside of the longest-dated debt facility to be entered into by the Reorganized Company Parties on the Effective Date, provided that in no event shall the maturity of the Takeback Debt be longer than eight years from the Effective Date;  to the extent the Original Second Lien Notes claims are reinstated under the Plan, the Takeback Debt will be third lien debt, provided that to the extent the Original Second Lien Notes claims are paid in full in cash during the pendency of the Chapter 11 Cases or under the Plan, the Company Parties and the Required Consenting Noteholders will agree on whether the Takeback Debt will be secured or unsecured, within three business days of the Company Parties’ delivery to the Consenting Noteholders of a term sheet for the financing to repay the Second Lien Notes in full in cash that contains terms and conditions reasonably acceptable to the Company Parties and the Required Consenting Noteholders;  the Takeback Debt amount is subject to downward adjustment by the Consenting Noteholders holding at least sixty-six and two-thirds percent of the aggregate outstanding principal amount of senior notes that are held by all Consenting Noteholders; and  all other terms including, without limitation, covenants and governance, shall be reasonably acceptable to the Company Parties and the Required Consenting Noteholders; provided that such terms shall not be more restrictive than those in the indenture for the Second Lien Notes. The Plan, among other things and subject to the terms of the Secured Creditor Settlement, contemplates the following treatment of claims against and interests in the Company Parties:  at the option of the applicable Reorganized Company Party, holders of secured claims against a Company Party that, absent its secured status, would be entitled to priority in right of payment under section 507(a)(8) of the Bankruptcy Code (determined irrespective of time limitations) (the Secured Tax Claims) shall receive (i) payment in full in cash or (ii) payment in cash made in equal semi-annual cash payments commencing as of the Effective Date or as soon as reasonably practicable thereafter and continuing for five years, in an aggregate amount equal to such claim, together with interest at the applicable non-default contract rate under non-bankruptcy law;  at the option of the applicable Company Party, holders of claims entitled to priority in right of payment under section 507(a) of the Bankruptcy Code other than Administrative Claims or Priority Tax Claims (each as defined in the Plan) shall receive payment in full in cash or such other treatment rendering such claims unimpaired;  claims arising under, derived from, based on, or related to the Company’s $ 850 million secured revolving credit facility maturing on February 27, 2024 (the Revolver) shall be repaid on or before the Effective Date, including payment of interest payments calculated at the non-default contract rate through the earlier of the Effective Date or repayment of the Revolver in full in cash (which shall include accrued but unpaid postpetition interest);  claims arising under, derived from, based on, or related to the JPM Credit Agreement shall be repaid on or before the Effective Date or reinstated on the Effective Date solely in the event that financing to repay such claims cannot be obtained, including payment of interest payments calculated at the non-default contract rate through the earlier of the Effective Date or repayment of Frontier’s $ 1,740 million senior secured Term Loan B facility (the Term Loan B) maturing on June 15, 2024 . in full in cash (which shall include accrued but unpaid postpetition interest);  claims arising under, derived from, based on, or related to the Original First Lien Notes, issued pursuant to the indenture, dated as of March 15, 2019, by and among the Company, as issuer, the subsidiary guarantors party thereto, JPMorgan Chase Bank, N.A., as collateral agent, and Wilmington Trust, National Association, as successor trustee, shall be repaid on or before the Effective Date or reinstated on the Effective Date, including payment of interest payments calculated at the non-default contract rate through the earlier of the Effective Date or repayment of the Original First Lien Notes in full in cash (which shall provide for the payment of accrued but unpaid postpetition interest);  claims arising under, derived from, based on, or related to the Original Second Lien Notes, issued pursuant to that certain indenture, dated as of March 19, 2018, by and among the Company, as issuer, the subsidiary guarantors party thereto, and Wilmington Savings Fund Society FSB, as successor trustee and successor collateral agent (the Second Lien Notes Trustee), shall be repaid on or before the Effective Date or reinstated on the Effective Date, including payment of interest payments calculated at the non-default contract rate as required through the earlier of the Effective Date or repayment of the Second Lien Notes in full in cash (which shall provide for the payment of accrued but unpaid postpetition interest);  claims arising under, derived from, based on or related to (a) the 8.500 % secured notes due November 15, 2031 , issued by Frontier Southwest Incorporated pursuant to the Restated Indenture, dated June 1, 1940, by and among Frontier Southwest Incorporated, as issuer, and BOKF, NA, as successor trustee, and (b) Rural Utilities Service loan contracts due January 3, 2028 (collectively, the Subsidiary Secured Notes) shall be reinstated on the Effective Date, with holders of such claims receiving ordinary course cash interest payments at the applicable non-default contract rate through the Effective Date;  claims arising under, derived from, based on or related to the 6.750 % unsecured notes due May 15, 2027 issued by Frontier California Inc., the 6.860 % unsecured notes due February 1, 2028 issued by Frontier Florida LLC, the 6.730 % unsecured notes due February 15, 2028 issued by Frontier North Inc., the 8.400 % unsecured notes due October 15, 2029 issued by Frontier West Virginia Inc. and the applicable indentures, debentures and purchase agreements associated therewith shall be reinstated on the Effective Date, with holders of such claims receiving ordinary course cash interest payments at the applicable non-default contract rate through the Effective Date;  holders of claims arising under, derived from, based on, or related to the unsecured notes issued by the Company shall receive their (i) pro rata share of and interest in the Incremental Senior Notes Payment Amount (as defined in the Plan) and (ii) pro rata share of and interest in (after first reducing, for distribution purposes only, the amount of each such holder’s senior notes claim on a dollar-for-dollar basis by the amount of Incremental Senior Notes Payments, and solely to the extent actually paid): (a) 100% of the Reorganized Company’s new common stock, subject to dilution by the Reorganized Company’s management incentive plan; (b) the Takeback Debt, if any; and (c) the Surplus Cash (as defined in the Plan), if any;  to the extent not already satisfied during the Chapter 11 Cases, holders of certain other claims that are not secured shall receive: (i) payment in full in cash; (ii) reinstatement; or (iii) such other treatment rendering such claims unimpaired, in each case as reasonably acceptable to the Company Parties and the Required Consenting Noteholders;  holders of secured claims (other than claims arising under, derived from, based on or related to the Revolver, the Term Loan B, the Original First Lien Notes, the Second Lien Notes, the Subsidiary Secured Notes, the Secured Tax Claims or DIP Facilities) shall receive, at the option of the applicable Company Party: (i) payment in full in cash, (ii) reinstatement; (iii) delivery of the collateral securing such claim; or (iv) such other treatment rendering such claim unimpaired;  claims subject to subordination under section 510(b) of the Bankruptcy Code shall be cancelled, released, discharged, and extinguished;  all intercompany claims and intercompany interests shall be either (a) reinstated or (b) cancelled on the Effective Date; and  all equity securities in the Company shall be cancelled, released and extinguished on the Effective Date. For more information on the repayment of the Revolver, the Original First Lien Notes, the Original Second Lien Notes and the Term Loan B, see Note 9. Secured Creditor Settlement The Plan will effectuate the settlement, release, compromise, discharge, and other resolution of all outstanding claims, interests, and causes of action, including the Objection of the Ad Hoc First Lien Committee to the Debtors’ Third Amended Joint Plan of Reorganization Pursuant to Chapter 11 of the Bankruptcy Code [Docket No. 857], the Objection of the Second Lien Notes Trustee to the Debtors’ Third Amended Joint Plan of Reorganization Pursuant to Chapter 11 of the Bankruptcy Code [Docket No. 858], and the Second Lien Committee’s Joinder to the Second Lien Notes Trustee’s Objection [Docket No. 860], as between the Company Parties, the ad hoc committee of certain unaffiliated holders of Term Loan B claims and Original First Lien Notes claims (the First Lien Committee) represented by Paul, Weiss, Rifkind, Wharton & Garrison LLP and PJT Partners LP, the Second Lien Notes Trustee, and the ad hoc committee of certain unaffiliated holders of Original Second Lien Notes claims represented by Quinn Emanuel Urquhart & Sullivan, LLP (the Second Lien Committee) (such settlement, the Secured Creditor Settlement). The Secured Creditor Settlement includes, among other terms and subject to certain conditions, the following key terms:  holders of Term Loan B claims, Original First Lien Notes claims, and Original Second Lien Notes claims, and the First Lien Committee and Second Lien Committee, shall be deemed to have consented to reinstatement and shall not allege, and shall be deemed to have waived and foregone any objections to, any defaults arising from the transactions set forth in the Plan;  holders of Term Loan B claims, Original First Lien Notes claims, and Original Second Lien Notes claims, and the First Lien Committee and Second Lien Committee shall be deemed to have consented to and shall not impede or otherwise delay the Debtors’ pursuit of certain debtor in possession/exit financing facilities;  holders of Term Loan B claims, Original First Lien Notes claims, and Original Second Lien Notes claims, and the First Lien Committee and Second Lien Committee, shall waive and forgo any and all “make-whole” claims and claims to default interest under the JPM Credit Agreement, the Original First Lien Notes indenture, and/or the Second Lien Notes indenture, as applicable;  holders of Revolver claims, Term Loan B claims, Original First Lien Notes claims (including the First Lien Committee), the applicable agents, and the Original First Lien Notes trustee shall be deemed to have waived any enforcement of any turnover or payment over rights under the Junior Lien Intercreditor and Subordination Agreement, dated as of March 19, 2018, against the Debtors, Second Lien Notes Trustee, or holders of Original Second Lien Notes claims with respect to certain obligations and amounts;  the Company Parties shall make a $ 48 million payment to holders of Term Loan B claims, a $ 9 million payment for the benefit of holders of Original First Lien Notes claims, and, in the event that the Effective Date occurs on or after March 31, 2021, an incremental payment of $ 8 million to holders of Term Loan B claims, subject to the provisions and conditions of the Plan with respect to such payments;  the Company Parties or the Reorganized Company Parties, as applicable, shall pay in full in cash all reasonable First Lien Committee fees and Second Lien Committee fees that are due and owing under the applicable engagement letters; and  all adequate protection currently in effect shall remain in effect until entry of a final adequate protection order and, upon the Company Parties’ entry into any DIP Facilities, the Bankruptcy Court shall enter a final adequate protection order granting, among other things, adequate protection to secured creditors in the form of (i) liens and claims on all collateral securing any future DIP Facilities, and (ii) cash payments in the amount of accrued interest. DIP Financing As previously disclosed, prior to the commencement of the Chapter 11 Cases, the Company and certain of its domestic subsidiaries entered into that certain Commitment Letter, dated April 14, 2020 (as amended by that certain Letter Agreement, dated April 28, 2020, by that certain Letter Agreement, dated May 12, 2020, by that certain Letter Agreement, dated June 10, 2020, by that certain Letter Agreement, dated June 29, 2020 and as further amended, modified or supplemented from time to time, the Original Commitment Letter) with Goldman Sachs Bank USA (GS Bank), Deutsche Bank AG New York Branch (DBNY), Deutsche Bank Securities Inc. (DBSI and, collectively with DBNY, DB), Barclays Bank PLC (Barclays), Morgan Stanley Senior Funding, Inc. (MSSF), Credit Suisse AG, Cayman Islands Branch (CS) and Credit Suisse Loan Funding LLC (CSLF and, together with CS and their respective affiliates, Credit Suisse, and together with GS Bank, DB, Barclays and MSSF, the Original Commitment Parties), pursuant to which, and subject to the satisfaction of certain customary conditions, including the approval of the Bankruptcy Court, GS Bank, DBNY, Barclays, MSSF and CS committed to provide a portion of the senior secured superpriority revolving credit facility in an aggregate principal amount of $ 460 million, which, upon satisfaction of certain conditions, including the effectiveness of the Plan, would convert into a longer term revolving exit facility. The Original Commitment Letter lapsed in accordance with its terms. The Company and certain of its domestic subsidiaries entered into a Commitment Letter, dated August 13, 2020, with the Original Commitment Parties, which was amended and restated by that certain Amended and Restated Commitment Letter, dated August 28, 2020, with the Original Commitment Parties and JPMorgan Chase Bank, N.A. (JPM) (collectively, the New Commitment Parties), pursuant to which, and subject to the satisfaction of certain customary conditions, including the approval of the Bankruptcy Court, GS Bank, JPM, DBNY, MSSF and CS committed to provide a portion of the $ 625 million DIP Revolving Facility, which, upon satisfaction of certain conditions, including the effectiveness of the Plan, would convert into a longer term revolving exit facility (the Exit Revolving Facility). On August 14, 2020, the Company and certain of its subsidiaries entered into an engagement letter, which was amended and restated on August 28, 2020 by that certain Amended and Restated Engagement Letter by and among the Company and certain of its subsidiaries and Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, DBSI, Barclays Capital Inc., Morgan Stanley & Co. LLC and Credit Suisse Securities (USA) LLC, in connection with a proposed issuance, offering and sale senior secured superpriority first lien and/or second lien notes to be issued by the Company or an affiliate thereof. The Company and certain of its domestic subsidiaries also entered into that certain Engagement Letter, dated August 14, 2020, with GS Bank, which was amended and restated by that certain Amended and Restated Engagement Letter, dated August 28, 2020 with the New Commitment Parties, in connection with the DIP Term Loan Facility, which, upon satisfaction of certain conditions, including the effectiveness of the Plan, would convert into a term loan Exit Facility (the Exit Term Loan Facility). On August 28, 2020, the Company Parties filed a motion (the DIP Financing Motion) with the Bankruptcy Court to approve the indentures, credit, guarantee and security documents governing the obligations under senior secured superpriority first lien and/or second lien notes to be issued by the Company or an affiliate thereof, a debtor-in-possession (DIP) revolving facility ,and the exit revolving facility ,(the Exit Revolving Facility) it would convert into upon satisfaction of certain conditions, including the effectiveness of the Plan, a DIP term loan facility and the exit term loan facility it would convert into upon satisfaction of certain conditions, including the effectiveness of the Plan (the Exit Term Loan Facility) and, if applicable, the reinstated Term Loan B (collectively, the DIP Financing). On September 17, 2020, the Bankruptcy Court entered the final order approving the DIP Financing Motion. On October 8, 2020, we issued $ 1,150 million aggregate principal amount of 5.875 % First Lien Secured Notes due October 15, 2027 (the First Lien Notes due October 2027), and entered into a $ 625 million DIP revolving facility (the DIP Revolving Facility) and a $ 500 million DIP term loan facility (the Initial DIP Term Loan Facility) . We used the proceeds from the offering of the First Lien Notes due October 2027, together with the proceeds of the Initial DIP Term Loan Facility and cash on hand, to (i) repay in full our prepetition $ 1,650 million aggregate principal amount of the Original First Lien Notes and (ii) pay related interest, fees and expenses. On November 25, 2020, we issued $ 1,550 million aggregate principal amount of 5.000 % First Lien Secured Notes due May 1, 2028 (the First Lien Notes due May 2028) and $ 1,000 million aggregate principal amount of 6.750 % Second Lien Secured Notes due May 1, 2029 (the New Second Lien Notes), and borrowed an incremental $ 750 million under the DIP term loan facility (the Incremental DIP Term Loan Facility and, together with the Initial DIP Term Loan Facility, the DIP Term Loan Facility). We used the proceeds from these issuances, and the incremental term loan borrowing, together with cash on hand to (i) repay all outstanding borrowings under the prepetition $ 1,740 million Term Loan B, (ii) repay in full the $ 1,600 million aggregate principal amount of the Original Second Lien Notes, and (iii) pay related interest, fees and expenses incurred in connection therewith. For more information about the DIP Financing, refer to Note 9. Regulatory Approvals As set forth in the Plan and the Disclosure Statement, in order to implement the restructuring contemplated by the Plan, the Company Parties must satisfy several conditions after confirmation of the Plan but prior to emergence from Chapter 11. Among other things, the Company Parties must obtain requisite regulatory approvals, including FCC and required Public Utility Commission (PUC) approvals in certain states, the level of review undertaken by the FCC and state PUCs, and the length of time to complete such review varies. As part of the regulatory approval process, t he Company made a number of affirmative commitments and the FCC and states have imposed additional conditions on the Company as part of approval for the Restructuring, including specific investment, broadband service deployment, service quality improvements, reporting and compliance conditions. The regulatory approval process is moving forward, and the Company has received PUC approvals or favorable determinations in all of the required states at this time, except California. No assurance can be given as to the terms, conditions, and timing of the remaining California approval. Executory Contracts Subject to certain exceptions, under the Bankruptcy Code, the Company Parties may assume, amend, or reject certain executory contracts and unexpired leases with respect to their operations with the approval of the Bankruptcy Court. Generally, the rejection of an executory contract or unexpired lease is treated as a pre-petition breach of such executory contract or unexpired lease and, subject to certain exceptions, relieves the Company Parties from performing their future obligations under such executory contract or unexpired lease but entitles the contract counterparty or lessor to a pre-petition general unsecured claim for damages caused by such deemed breach. Generally, the assumption of an executory contract or unexpired lease requires the Company Parties to cure existing monetary defaults under such executory contract or unexpired lease and provide adequate assurance of future performance. Accordingly, any description of an executory contract or unexpired lease with the Company Parties in this document, including where applicable a quantification of the Company’s obligations under any such executory contract

Revenue Recognition

Revenue Recognition	12 Months Ended
Revenue Recognition	Dec. 31, 2020
Revenue Recognition [Abstract]
Revenue Recognition	(4) Revenue Recognition: Effective January 1, 2018, we adopted ASU 2014-09, “Revenue from Contracts with Customers,” (ASC 606). We categorize our products, services and other revenues into the following categories: Data and Internet services include broadband services for residential and business customers. We provide data transmission services to high volume business customers and other carriers with dedicated high capacity circuits (nonswitched access) including services to wireless providers (wireless backhaul); Voice services include traditional local and long-distance wireline services, Voice over Internet Protocol (VoIP) services, as well as a number of unified messaging services offered to our residential and business customers. Voice services also include the long-distance voice origination and termination services that we provide to our business customers and other carriers; Video services include revenues generated from services provided directly to residential customers as terrestrial television services, and through Dish satellite TV services; Other customer revenue includes switched access revenue, sales of customer premise equipment to our business customers, rents collected for collocation services, and revenue from other services and fees. Switched access revenue includes revenues derived from allowing other carriers to use our network to originate and/or terminate their local and long-distance voice traffic (switched access). These services are primarily billed on a minutes-of-use basis applying tariffed rates filed with the FCC or state agencies; and Subsidy and other regulatory revenue includes revenues generated from cost subsidies from state and federal authorities, including the Connect America Fund Phase II. The following tables provide a summary of revenues, by category. Revenues in the following tables include revenues for the Northwest Operations for the four months ended April 30, 2020 (prior to its disposal): For the year ended December 31, ($ in millions) 2020 2019 2018 Data and Internet services $ 3,478 $ 3,756 $ 3,878 Voice services 2,085 2,500 2,721 Video services 789 1,005 1,085 Other 429 477 544 Revenue from contracts with customers (1) 6,781 7,738 8,228 Subsidy and other regulatory revenue (2) 374 369 383 Total revenue $ 7,155 $ 8,107 $ 8,611 For the year ended December 31, ($ in millions) 2020 2019 2018 Consumer $ 3,586 $ 4,153 $ 4,380 Commercial 3,195 3,585 3,848 Revenue from contracts with customers (1) 6,781 7,738 8,228 Subsidy and other regulatory revenue (2) 374 369 383 Total revenue $ 7,155 $ 8,107 $ 8,611 (1) Includes $ 67 million, $ 70 million, and $ 73 million of lease revenue for the years ended December 31, 2020, 2019, and 2018 respectively. (2) Includes $ 30 million in transition services provided to the purchaser in connection with the divestiture of the Northwest Operations for the year ended December 31, 2020. Frontier satisfies its obligations to customers by transferring goods and services in exchange for consideration received from the customer. The timing of Frontier’s satisfaction of the performance obligation often differs from the timing of the customer’s payment, which results in the recognition of a contract asset or a contract liability. Frontier recognizes a contract asset or liability when the Company transfers goods or services to a customer and bills an amount which differs from the revenue allocated to the related performance obligations. The following is a summary of the changes in the assets established for our costs to acquire customers for the years ended December 31, 2020 and 2019: Contract Acquisition Costs ($ in millions) Current Noncurrent Balance at January 1, 2019 $ 107 $ 127 Commissions deferred 138 6 Commission costs recognized ( 131 ) - Reclass to assets held for sale ( 9 ) ( 12 ) Balance at December 31, 2019 105 121 Commissions deferred 94 13 Commission costs recognized ( 116 ) ( 4 ) Reclassified between Current and Noncurrent 14 ( 14 ) Balance at December 31, 2020 $ 97 $ 116 The following is a summary of the changes in the contract assets and contract liabilities for the years ended December 31, 2020 and 2019: Contract Assets Contract Liabilities ($ in millions) Current Noncurrent Current Noncurrent Balance at January 1, 2020 $ 37 $ 8 $ 41 $ 21 Revenue recognized included in opening contract balance ( 34 ) - ( 68 ) ( 12 ) Cash received, excluding amounts recognized as revenue - - 85 11 Credits granted, excluding amounts recognized as revenue 3 1 - - Reclassified between Current and Noncurrent - - - - Balance at December 31, 2020 $ 6 $ 9 $ 58 $ 20 Contract Assets Contract Liabilities ($ in millions) Current Noncurrent Current Noncurrent Balance at January 1, 2019 $ 44 $ 25 $ 49 $ 22 Revenue recognized included in opening contract balance ( 39 ) ( 12 ) ( 81 ) ( 17 ) Cash received, excluding amounts recognized as revenue - - 78 16 Credits granted, excluding amounts recognized as revenue 30 1 - - Reclassified between Current and Noncurrent 5 ( 5 ) - - Reclassified to held for sale ( 3 ) ( 1 ) ( 5 ) - Balance at December 31, 2019 $ 37 $ 8 $ 41 $ 21 Short-term contract assets, Long-term contract assets, Short-term contract liabilities, and Long-term contract liabilities are included in other current assets, other assets, other current liabilities, and other liabilities, respectively, on our consolidated balance sheet. The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period. Revenue from remaining ($ in millions) performance obligations 2021 $ 1,426 2022 651 2023 288 2024 118 2025 69 Thereafter 139 Total $ 2,691

Accounts Receivable

Accounts Receivable	12 Months Ended
Accounts Receivable	Dec. 31, 2020
Accounts Receivable [Abstract]
Accounts Receivable	(5) Accounts Receivable : The components of accounts receivable, net at December 31, 2020 and 2019 are as follows: ($ in millions) 2020 2019 Retail and Wholesale $ 608 $ 678 Other 75 71 Less: Allowance for doubtful accounts ( 130 ) ( 120 ) Accounts receivable, net $ 553 $ 629 An analysis of the activity in the allowance for doubtful accounts for the years ended December 31, 2020, 2019 and 2018 is as follows: Decreases: Reclassified Balance at ASC 606 Increases: Write-offs to Balance at beginning of Transition Charged to and Customer Assets Held end of ( $ in millions ) the Period Adjustment Revenue Credits for Sale the Period 2018 $ 69 $ 32 $ 93 $ ( 89 ) $ - $ 105 2019 $ 105 $ - $ 109 $ ( 83 ) $ ( 11 ) $ 120 2020 $ 120 $ - $ 106 $ ( 96 ) $ - $ 130 We maintain an allowance for doubtful accounts based on our estimate of our ability to collect accounts receivable. The provision for uncollectible amounts was $ 106 million, $ 109 million and $ 93 million for the years ended December 31, 2020, 2019 and 2018, respectively. The provision for uncollectible amounts charged to revenue during 2020 and 2019 and the ending balance in the allowance account as of December 31, 2020 and 2019 were elevated as a result of ongoing billing disputes with some of our wholesale customers and our estimate of amounts required to settle such disputes. Actual settlement amounts could vary significantly from these estimates. Resolutions reached with carriers resulted in a reduction of our reserves of $ 49 million, $ 37 million, and $ 9 million in 2020, 2019 and 2018, respectively.

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
Property, Plant And Equipment	Dec. 31, 2020
Property, Plant And Equipment [Abstract]
Property, Plant And Equipment	(6) Property, Plant and Equipment : Property, plant and equipment, net at December 31, 2020 and 2019 are as follows: Estimated ($ in millions) Useful Lives 2020 2019 Land N/A $ 212 $ 217 Buildings and leasehold improvements 40 years 2,139 2,171 General support 5 to 15 years 1,643 1,624 Central office/electronic circuit equipment 5 to 8 years 8,270 7,968 Poles 30 years 1,371 1,274 Cable, fiber and wire 15 to 25 years 11,883 11,312 Conduit 50 years 1,619 1,608 Construction work in progress 558 378 Property, plant and equipment 27,695 26,552 Less: Accumulated depreciation ( 14,764 ) ( 13,589 ) Property, plant and equipment, net $ 12,931 $ 12,963 As of December 31, 2019, $ 1,049 million of fixed assets were reclassified to assets held for sale in relation to the planned sale of the Northwest Operations (see Note 7). Effective with the designation of the Northwest Operations as held-for-sale on May 28, 2019, we discontinued recording depreciation on Property, Plant and Equipment and finite-lived intangible assets of this business as required by GAAP. Property, plant, and equipment includes approximately $ 143 million, $ 167 million, and $ 152 million of fixed assets recognized under capital leases as of December 31, 2020, 2019 and 2018, respectively. During 2020, we sold certain properties consisting of land and buildings for approximately $ 27 million in cash. The aggregate carrying value of the properties was approximately $ 37 million, resulting in a loss on the sale of $ 10 million, which, given our composite group method of accounting for depreciation, was recognized against “Accumulated Depreciation” in our consolidated balance sheet. In 2017 and 2018, we sold certain properties subject to leaseback, generating $ 106 million in net proceeds. In connection with the adoption of ASC 842, the $ 15 million ($ 11 million net of tax) unamortized deferred gains resulting from these transactions were recognized directly to opening accumulated deficit as of January 1, 2019. In January 2019, we closed the sale of certain wireless towers for approximately $ 76 million in cash. The aggregate carrying value of the towers was approximately $ 1 million, resulting in a gain on the sale of $ 75 million which, given our composite group method of accounting for depreciation, was recognized against “Accumulated Depreciation” in our consolidated balance sheet during 2020. Depreciation expense is principally based on the composite group method. Depreciation expense was as follows: For the year ended December 31, ($ in millions) 2020 2019 2018 Depreciation expense $ 1,255 $ 1,335 $ 1,385 We adopted revised estimated remaining useful lives for certain plant assets as of October 1, 2020, as a result of an annual independent study of the estimated remaining useful lives of our plant assets, with an insignificant impact to depreciation expense.

Divestiture Of Northwest Operat

Divestiture Of Northwest Operations	12 Months Ended
Divestiture Of Northwest Operations	Dec. 31, 2020
Divestiture Of Northwest Operations [Abstract]
Divestiture Of Northwest Operations	(7) Divestiture of Northwest Operations: On May 1, 2020, Frontier completed the sale of its Northwest Operations pursuant to the terms and conditions of the Purchase Agreement, dated as of May 28, 2019, for gross proceeds of $ 1,352 million, subject to certain closing adjustments. Net of funding certain pension and other retiree medical liabilities, funding of indebtedness, funding certain escrows and other closing adjustments, we received $ 1,131 million in proceeds. A portion of the proceeds from the sale are held in escrow as recourse for indemnity claims that may arise under the purchase agreement for a period of one year after the sale was completed on May 1, 2020. As of December 31, 2020, there were $ 58 million of proceeds held in escrow accounts included in Other current assets. Proceeds previously held in escrow related to employee liabilities of $ 25 million and adjustments to working capital of $ 5 million were received by the Company in the first quarter of 2021. In connection with the sale, Frontier entered into an agreement to perform certain transition services for the purchaser. The first six months of these services were generally being provided at no additional cost to the purchaser as a condition of the transaction. The fair value of these transition services was estimated to be $ 30 million and were recorded as a deferred liability (recorded within the “Advanced billings” financial statement caption in the balance sheet) in connection with the transaction, which amount was amortized to other revenue as the related services are being delivered. For the year ended December 31, 2020, we recognized $ 30 million, in other revenue related to these transition services. Effective October 31, 2020, the purchaser terminated all future services that Frontier would have provided and received compensation under this agreement. In connection with the termination, Frontier agreed to provide limited training and subject matter support services for a fee, primarily during the fourth quarter of 2020. The Northwest Operations were included in Frontier’s continuing operations and classified as assets held for sale and liabilities related to assets held for sale on our consolidated balance sheets through the completion of the transaction on May 1, 2020. As a result of the closing of the transaction, we derecognized net assets of $ 1,132 million, including property, plant, and equipment of $ 1,084 million, goodwill of $ 658 million, a $ 603 million valuation allowance on our assets held for sale, and $ 150 million of defined benefit pension and other postretirement benefit plan obligations, net of transferred pension plan assets. This transaction did not represent a strategic shift for Frontier; therefore, it did not meet the criteria to be classified as a discontinued operation. Effective with the designation as held-for-sale on May 28, 2019, we discontinued recording depreciation on Property, Plant and Equipment and finite-lived intangible assets of this business as required by GAAP. During the years ended December 31, 2020 and 2019, Frontier recorded a loss on disposal of $ 162 million and $ 446 million, respectively, associated with the sale of the Northwest Operations. For the year ended December 31, 2020, these amounts include $ 27 million of loss (an immaterial out of period adjustment) related to the initial measurement and recognition of the estimated loss on disposal recorded during the quarter ended June 30, 2019, upon designation as assets held for sale.

Goodwill And Other Intangibles

Goodwill And Other Intangibles	12 Months Ended
Goodwill And Other Intangibles	Dec. 31, 2020
Goodwill And Other Intangibles [Abstract]
Goodwill And Other Intangibles	(8) Goodwill and Other Intangibles : All goodwill was fully impaired as of December 31, 2019, other than goodwill of $ 658 million associated with the planned disposal of Frontier Northwest which was classified in Assets held for sale as of December 31, 2019. Goodwill impairment charges were $ 5,725 million and $ 641 million for the years ended December 31, 2019 and 2018, respectively. Accumulated goodwill impairment charges were $ 9,154 million as of both December 31, 2020 and 2019. Prior to full impairment, we performed impairment tests related to our goodwill annually as of December 31, or sooner if an indicator of impairment was identified. We used a market multiples approach to determine Frontier’s enterprise fair value for purposes of assessing goodwill for impairment. Marketplace comparisons, analyst reports and trends for other public companies within the communications industry whose service offerings are comparable to ours had a range of fair value multiples between 4.4 x and 6.5 x of annualized expected EBITDA as adjusted for certain items. We estimated the enterprise fair value using a multiple of 4.4 x EBITDA for both the second and third quarter 2019 evaluations, a multiple of 5.3 x EBITDA for the fourth quarter 2018 evaluation, and a multiple of 5.5 x EBITDA for each of the first three quarterly evaluations in 2019. We recorded goodwill impairments totaling $ 5,725 million for the year ended December 31, 2019. The impairment in the second and third quarters of 2019 reflected lower enterprise valuation driven by lower profitability, as well as a reduction in the utilized market multiple from 5.3 x EBITDA at December 31, 2018 to the 4.4 x EBITDA utilized during our quantitative assessments in 2019. This reflected, among other things, pressures on our business resulting in the continued deterioration in revenue, challenges in achieving improvements in revenue and customer trends, the long-term sustainability of our capital structure, and the lower outlook of our industry as a whole. We recorded goodwill impairments totaling $ 641 million for year ended December 31, 2018. The driver for the impairment in the third quarter of 2018 was a reduction in our profitability and utilized EBITDA estimate, which when applied to our market multiple resulted in a lower enterprise valuation. During the fourth quarter of 2018, the impairment was largely driven by a lower enterprise valuation resulting from a reduction in utilized market multiple from 5.5 x to 5.3 x reflecting the lower outlook for our industry as a whole. We also considered whether the carrying values of finite-lived intangible assets and property plant and equipment may not be recoverable or whether the carrying value of certain indefinite-lived intangible assets were impaired. No impairment was present for either intangibles or property plant and equipment as of December 31, 2020, 2019, and 2018. The components of other intangibles at December 31, 2020 and 2019 are as follows: 2020 2019 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying ($ in millions) Amount Amortization Amount Amount Amortization Amount Other Intangibles: Customer base $ 4,332 $ ( 3,781 ) $ 551 $ 4,332 $ ( 3,452 ) $ 880 Trade name 122 - 122 122 - 122 Royalty agreement 72 ( 68 ) 4 72 ( 54 ) 18 Total other intangibles $ 4,526 $ ( 3,849 ) $ 677 $ 4,526 $ ( 3,506 ) $ 1,020 Amortization expense was as follows: For the year ended December 31, ($ in millions) 2020 2019 2018 Amortization expense $ 343 $ 445 $ 569 Amortization expense primarily represents the amortization of our customer base acquired as a result of the CTF Acquisition, the Connecticut Acquisition and the acquisition of certain Verizon properties in 2010 with each based on a useful life of 8 to 12 years on an accelerated method. The approximate weighted average remaining life of our customer base is 3.5 years and for our royalty agreement is 0.3 years. Amortization expense based on our current estimate of useful lives, is estimated to be approximately $ 253 million in 2021, $ 170 million in 2022, $ 95 million in 2023, $ 26 million in 2024, and $ 7 million in 2025.

Long-Term Debt

Long-Term Debt	12 Months Ended
Long-Term Debt	Dec. 31, 2020
Long-Term Debt [Abstract]
Long-Term Debt	(9) Long-Term Debt : The filing of the Chapter 11 Cases constituted an event of default that accelerated substantially all of our obligations under the JPM Credit Agreement, the Original First Lien Notes, the Second Lien Notes, our unsecured notes and debentures and the secured and unsecured debentures of our subsidiaries. As such we have reclassified certain subsidiary unsecured and certain secured debt obligations to Long term debt due within one year and certain parent unsecured debt obligations to Liabilities subject to compromise on our consolidated balance sheet as of December 31, 2020. While this reclassification includes all of our debt, the Restructuring Support Agreement contemplates agreed-upon terms for a pre-arranged financial restructuring Plan that leaves unimpaired all holders of secured debt and subsidiary debt. Among other things, the Restructuring Support Agreement provides that holders of our secured debt will be entitled to receive cash interest payments and to have the principal amount of their indebtedness repaid or reinstated upon emergence and that holders of secured and unsecured debt of our subsidiaries will be entitled to receive cash interest payments and to have the principal amount of their indebtedness reinstated upon emergence. Pursuant to Section 362 of the Bankruptcy Code, the filing of the Chapter 11 Cases automatically stayed most actions against or on behalf of the Company Parties, including actions to collect indebtedness incurred prior to the Petition Date or to exercise control over the Company Parties’ property. For information related to the Restructuring Support Agreement, the Chapter 11 Cases, the Plan and the DIP Financing, refer to Note 3. The activity in our long-term debt from January 1, 2020 to December 31, 2020 is summarized as follows: For the year ended December 31, 2020 ($ in millions) January 1, 2020 Payments and Retirements New Borrowings December 31, 2020 Interest Rate at December 31, 2020* Secured debt issued by Frontier $ 5,711 $ ( 5,697 ) $ 4,950 $ 4,964 5.747 % Unsecured debt issued by Frontier 10,949 - - 10,949 9.193 % Secured debt issued by subsidiaries 106 - - 106 8.368 % Unsecured debt issued by subsidiaries 750 - - 750 6.897 % Debt prior to reclassification to liabilities subject to compromise $ 17,516 $ ( 5,697 ) $ 4,950 $ 16,769 8.065 % Less: Debt Issuance Costs ( 168 ) - Less: Debt Premium/(Discount) ( 46 ) ( 39 ) Debt, less unamortized debt issuance costs and discounts 17,302 16,730 Less: Current Portion ( 994 ) ( 5,781 ) Less: Debt subject to compromise - ( 10,949 ) Total Long-term debt $ 16,308 $ - * Interest rate includes amortization of debt issuance costs and debt premiums or discounts. The interest rates at December 31, 2020 represent a weighted average of multiple issuances. Since the filing of Chapter 11 Bankruptcy, Frontier has not made any payments related to accrued interest for any debt obligations that are subject to compromise. Additional information regarding our senior unsecured debt, senior secured debt and subsidiary debt at December 31, 2020 and 2019 is as follows: December 31, 2020 December 31, 2019 Principal Interest Principal Interest ($ in millions) Outstanding Rate Outstanding Rate Secured debt issued by Frontier Revolver due 2/27/2024 (1) $ - $ 749 4.760 % (Variable) Term loan due 6/15/2024 (2) - 1,699 5.550 % (Variable) First lien notes due 4/1/2027 - 1,650 8.000 % Second lien notes due 4/1/2026 - 1,600 8.500 % DIP-to-Exit Revolving Facility - - DIP-to-Exit term loan due 10/8/2027 1,250 5.750 % (Variable) - DIP-to-Exit First lien notes due 10/15/2027 1,150 5.875 % - DIP-to-Exit First lien notes due 5/1/2028 1,550 5.000 % - DIP-to-Exit Second lien notes due 5/1/2029 1,000 6.750 % - IDRB due 5/1/2030 14 6.200 % 13 6.200 % Total secured debt issued by Frontier 4,964 5,711 Unsecured debt issued by Frontier Senior notes due 4/15/2020 172 8.500 % 172 8.500 % Senior notes due 9/15/2020 55 8.875 % 55 8.875 % Senior notes due 7/1/2021 89 9.250 % 89 9.250 % Senior notes due 9/15/2021 220 6.250 % 220 6.250 % Senior notes due 4/15/2022 500 8.750 % 500 8.750 % Senior notes due 9/15/2022 2,188 10.500 % 2,188 10.500 % Senior notes due 1/15/2023 850 7.125 % 850 7.125 % Senior notes due 4/15/2024 750 7.625 % 750 7.625 % Senior notes due 1/15/2025 775 6.875 % 775 6.875 % Senior notes due 9/15/2025 3,600 11.000 % 3,600 11.000 % Debentures due 11/1/2025 138 7.000 % 138 7.000 % Debentures due 8/15/2026 2 6.800 % 2 6.800 % Senior notes due 1/15/2027 346 7.875 % 346 7.875 % Senior notes due 8/15/2031 945 9.000 % 945 9.000 % Debentures due 10/1/2034 1 7.680 % 1 7.680 % Debentures due 7/1/2035 125 7.450 % 125 7.450 % Debentures due 10/1/2046 193 7.050 % 193 7.050 % Total unsecured debt issued by Frontier 10,949 10,949 Secured debt issued by subsidiaries Debentures due 11/15/2031 100 8.500 % 100 8.500 % RUS loan contracts due 1/3/2028 6 6.154 % 6 6.154 % Total secured debt issued by subsidiaries 106 106 Unsecured debt issued by subsidiaries Debentures due 5/15/2027 200 6.750 % 200 6.750 % Debentures due 2/1/2028 300 6.860 % 300 6.860 % Debentures due 2/15/2028 200 6.730 % 200 6.730 % Debentures due 10/15/2029 50 8.400 % 50 8.400 % Total unsecured debt issued by subsidiaries 750 750 Debt prior to reclassification to liabilities subject to compromise 16,769 8.188 % (3) 17,516 8.486 % (3) Less: debt subject to compromise ( 10,949 ) - Total Debt $ 5,820 5.944 % (3) $ 17,516 8.486 % (3) (1) Represents borrowings under the JPM Credit Agreement Revolver, as defined below. (2) Represents borrowings under the JPM Credit Agreement Term Loan B, as defined below. (3) Interest rate represents a weighted average of the stated interest rates of multiple issuances . DIP Financing DIP Financing Motion On August 28, 2020, the Company Parties filed the DIP Financing Motion with the Bankruptcy Court to approve the indentures, credit, guarantee and security documents governing the New First Lien Notes, the DIP Revolving Facility, the DIP Term Loan Facility, the Exit Revolving Facility, the Exit Term Loan Facility and, if applicable, the reinstated Term Loan B. On September 17, 2020, the Bankruptcy Court entered the final order approving the DIP Financing Motion. DIP Revolving Facility On October 8, 2020, Frontier entered into the DIP Revolving Facility, pursuant to the senior secured superpriority debtor-in-possession credit agreement, dated as of October 8, 2020, by and among Frontier, as the borrower and a debtor and debtor-in-possession under Chapter 11 of the Bankruptcy Code, Goldman Sachs Bank USA, as administrative agent, JP Morgan Chase Bank, N.A., as collateral agent and each lender and issuing bank from time to time party thereto. The DIP Revolving Facility has a maturity of the earlier of (x) the date that is twelve months after the closing date of the DIP Revolving Facility and (y) the date of the substantial consummation of the Plan; provided that to the extent such substantial consummation has not occurred on or prior to the date referred to in the foregoing clause (x), primarily because any condition precedent set forth therein with respect to the procurement of regulatory approvals has not been satisfied (and other than any other conditions that by their nature can only be satisfied on the consummation date), the maturity date shall be extended by an additional six months. At our election, the determination of interest rates for the DIP Revolving Facility is based on margins over the alternate base rate or over LIBOR. The interest rate with respect to any LIBOR loan is 3.250 % (or 2.250 % for alternate base rate loans). Subject to customary exceptions and thresholds, the security package under the DIP Revolving Facility includes pledges of the equity interests in certain of our subsidiaries, which as of the issue date is limited to certain specified pledged entities, substantially all personal property of Frontier Video and substantially all of the unencumbered assets and properties of Frontier and Frontier Iowa, which such security interest in the unencumbered assets and properties was granted solely pursuant to the DIP financing order issued by the Bankruptcy Court, which same assets also secure the New First Lien Notes. The DIP Revolving Facility is guaranteed by the same subsidiaries that guarantee the New First Lien Notes. After giving effect to $ 90 million of letters of credit formerly outstanding under the Revolver that were rolled into, replaced or otherwise accommodated for under the DIP Revolving Facility, the Company has $ 535 million of available borrowing capacity under the DIP Revolving Facility. The DIP Revolving Facility includes usual and customary negative covenants for loan agreements of this type, including covenants limiting Frontier and its restricted subsidiaries’ (other than certain covenants therein which are limited to subsidiary guarantors) ability to, among other things, incur additional indebtedness, create liens on assets, make investments, loans or advances, engage in mergers, consolidations, sales of assets and acquisitions, pay dividends and distributions and make payments in respect of certain material payment subordinated indebtedness, in each case subject to customary exceptions for loan agreements of this type. The DIP Revolving Facility also includes certain customary representations and warranties, affirmative covenants and events of default, including, but not limited to, payment defaults, breaches of representations and warranties, covenant defaults, certain events under ERISA, change of control or damage to a material portion of the collateral. Upon the conversion date, subject to certain conditions, the DIP Revolving Facility shall convert into the Exit Revolving Facility with an aggregate principal amount of $ 625 million. The Exit Revolving Facility will be available on a revolving basis during the period commencing on the conversion date and ending on the date that is the earlier of (x) 4 years after the conversion date and (y) 91 days prior to the earliest maturity date of permitted pari passu refinancing debt, permitted junior refinancing debt, the term loans outstanding under the prepetition credit agreement after giving effect to the consummation of the Plan (or any indebtedness that replaces or refinances such term loans) and any long term exit facilities so long as, in each case, the outstanding principal amount of any such indebtedness is in excess of an amount set forth in the definitive documentation with respect to the Exit Revolving Facility. The determination of interest rates for the Exit Revolving Facility is based on margins over the alternate base rate or over LIBOR, at our election. The interest rate with respect to any LIBOR loan is 3.500 % (or 2.500 % for alternate base rate loans). DIP Term Loan Facility On October 8, 2020, Frontier entered into a credit agreement with JPMorgan Chase Bank, N.A., as administrative agent and collateral agent and each lender from time to time party thereto (the DIP to Exit Term Credit Agreement). which provides for a senior secured superpriority DIP term loan facility in the aggregate principal amount of $ 500 million (the Initial DIP Term Loan Facility). On November 25, 2020, Frontier entered into an incremental amendment to the DIP to Exit Term Credit Agreement (the Incremental DIP Term Loan Amendment), which provides for an additional senior secured superpriority DIP term loan facility in the aggregate principal amount of $ 750 million (the Incremental DIP Term Loan Facility and, together with the Initial DIP Term Loan Facility, the DIP Term Loan Facility). The DIP Term Loan Facility has a maturity of the earlier of (x) the date that is twelve months after the closing date of the DIP Term Loan Facility and (y) the date of the substantial consummation of the Plan; provided that to the extent such substantial consummation has not occurred on or prior to the date referred to in the foregoing clause (x), primarily because any condition precedent set forth therein with respect to the procurement of regulatory approvals has not been satisfied (and other than any other conditions that by their nature can only be satisfied on the consummation date), the maturity date shall be extended by an additional six months; provided that if certain conditions are met and the conversion date occurs, the maturity date shall be the seventh anniversary of the closing date. At our election, the determination of interest rates for the DIP Term Loan Facility are based on margins over the alternate base rate or over LIBOR. The interest rate with respect to any LIBOR loan is 4.750 % or 3.750 % for alternate base rate loans, with a 1.000 % LIBOR floor. Subject to certain exceptions and thresholds, the security package under the DIP Term Loan Facility includes pledges of the equity interests in certain of our subsidiaries, which as of the issue date is limited to certain specified pledged entities, substantially all personal property of Frontier Video Services Inc., a Delaware corporation (Frontier Video), and, solely prior to the conversion date, substantially all of the unencumbered assets and properties (the DIP Collateral) of Frontier and Frontier Communications of Iowa, LLC, an Iowa limited liability company (Frontier Iowa), which such security interest in the DIP Collateral was granted solely pursuant to the DIP financing order issued by the Bankruptcy Court, which same assets also secure the New First Lien Notes. The DIP Term Loan Facility is guaranteed by the same subsidiaries that guarantee the New First Lien Notes. Upon the conversion date, the security package will no longer include the DIP Collateral. The DIP Term Loan Facility includes usual and customary negative covenants for DIP to exit loan agreements of this type, including covenants limiting Frontier and its restricted subsidiaries’ (other than certain covenants therein which are limited to subsidiary guarantors) ability to, among other things, incur additional indebtedness, create liens on assets, make investments, loans or advances, engage in mergers, consolidations, sales of assets and acquisitions, pay dividends and distributions and make payments in respect of certain material payment subordinated indebtedness, in each case subject to customary exceptions for exit loan agreements of this type. The DIP Term Loan Facility also includes certain customary representations and warranties, affirmative covenants and events of default, including, but not limited to, payment defaults, breaches of representations and warranties, covenant defaults, certain events under ERISA, upon the conversion date, unstayed judgments in favor of a third party involving an aggregate liability in excess of a certain threshold, change of control, upon the conversion date, specified governmental actions having a material adverse effect or condemnation or damage to a material portion of the collateral. Upon the conversion date, subject to certain conditions, the DIP Term Loan Facility shall convert into the Exit Term Loan Facility with an aggregate principal amount of $ 1,250 million. Debt Refinancing On September 17, 2020, Frontier repaid the $ 749 million of outstanding principal under the Revolver (as defined below), plus accrued interest, using cash on hand. The repayment in full of all revolving loans outstanding under the JPM Credit Agreement (as defined below) was a condition precedent to the entry into the DIP Facility, and the Revolver was terminated on October 8, 2020 upon entry into the DIP Revolving Facility. On October 8, 2020, the Company issued $ 1,150 million aggregate principal amount of the First Lien Notes due October 2027, entered into the $ 500 million DIP Revolving Facility and entered into the Initial DIP Term Loan Facility. The Company used the proceeds from the offering, together with the proceeds of the DIP Term Loan Facility and cash on hand, to (i) repay in full the Company’s $ 1,650 million aggregate principal amount of Original First Lien Notes and (ii) pay related interest, fees and expenses. On November 25, 2020, the Company issued $ 1,550 million aggregate principal amount of the First Lien Notes due May 2028 (as defined below), issued $ 1,000 million aggregate principal amount of the New Second Lien Notes (as defined below), and borrowed an incremental $ 750 million pursuant to the Incremental DIP Term Loan Facility. The Company used the proceeds from the issuance, the incremental borrowing, and cash on hand to (i) repay all outstanding borrowings under our Term Loan B, (ii) repay in full the $ 1,600 million aggregate principal amount of the Original Second Lien Notes, and (iii) pay related interest, fees and expenses incurred in connection therewith. First Lien Notes due October 2027 On October 8, 2020, Frontier issued $ 1,150 million aggregate principal amount of the First Lien Notes due October 2027. Interest on the First Lien Notes due October 2027 is payable to holders of record semi-annually in arrears on April 15 and October 15 of each year, commencing April 15, 2021. The notes were issued pursuant to an indenture, dated as of October 8, 2020 (the 2027 First Lien Indenture), by and among Frontier, the guarantors party thereto, the grantor party thereto, JPMorgan Chase Bank N.A., as collateral agent and Wilmington Trust, National Association, as trustee, and were issued in a private offering exempt from the registration requirements of the Securities Act, to persons reasonably believed to be qualified institutional buyers in accordance with Rule 144A under the Securities Act and to persons outside the United States pursuant to Regulation S under the Securities Act, at a purchase price equal to 100% of the principal amount thereof. Prior to the conversion date, the First Lien Notes due October 2027 are secured on a super-priority basis and pari passu with the DIP Revolving Facility and the DIP Term Loan Facility, subject to permitted liens and certain exceptions, by all the assets that secure Frontier’s obligations under the DIP Revolving Facility and the DIP Term Loan Facility, on a super-priority basis and pari passu with the DIP Revolving Facility and the DIP Term Loan Facility. From the conversion date, the First Lien Notes due October 2027 are secured on a first-priority basis and pari passu with its senior secured credit facilities, subject to permitted liens and certain exceptions, by all the assets that secure Frontier’s obligations under its senior secured credit facilities on a first-priority basis and pari passu with its senior secured credit facilities. Frontier may redeem the First Lien Notes due October 2027 at any time, in whole or in part, prior to their maturity. If the notes are redeemed before October 15, 2023 the redemption price will be equal to 100% of the aggregate principal amount thereof, together with any accrued and unpaid interest, if any, to, but not including, the redemption date, plus a make-whole premium. If the notes are redeemed on or after October 15, 2023 the redemption price will be equal to the amounts set forth in the 2027 First Lien Indenture, together with any accrued and unpaid interest to the redemption date. In addition, at any time before October 15, 2023, Frontier may redeem up to 40 % of the First Lien Notes due October 2027 using the proceeds of certain equity offerings at a redemption price equal to 105.875 % of the aggregate principal amount thereof, together with any accrued and unpaid interest, if any, to, but not including, the redemption date. In the event of a change of control triggering event, each holder of the First Lien Notes due October 2027 will have the right to require Frontier to purchase the notes at a purchase price equal to 101 % of the principal amount of the First Lien Notes due October 2027, plus accrued and unpaid interest, if any, to, but not including, the date of repurchase. The 2027 First Lien Indenture contains customary negative covenants, subject to a number of important exceptions and qualifications, including, without limitation, covenants related to incurring additional debt and issuing preferred stock; incurring or creating liens; redeeming and/or prepaying certain debt; paying dividends on our stock or repurchasing stock; making certain investments; engaging in specified sales of assets; entering into transactions with affiliates; and engaging in consolidation, mergers and acquisitions. Certain of these covenants will be suspended during such time, if any, that the First Lien Notes due October 2027 have investment grade ratings by at least two of Moody’s, S&P or Fitch. The 2027 First Lien Indenture also provides for customary events of default which, if any of them occurs, would permit or require the principal of and accrued interest on the First Lien Notes due October 2027 to become or to be declared due and payable. First Lien Notes due May 2028 On November 25, 2020, Frontier issued $ 1,550 million aggregate principal amount of the First Lien Notes due May 2028 , which bear interest at a rate of 5.000 % per annum. Interest is payable to holders of record semi-annually in arrears on May 1 and November 1 of each year, commencing May 1, 2021. The First Lien Notes due May 2028 were issued pursuant to an indenture, dated as of November 25, 2020 (the 2028 First Lien Indenture), by and among Frontier, the guarantors party thereto, the grantor party thereto, JPMorgan Chase Bank N.A., as collateral agent and Wilmington Trust, National Association, as trustee, and were issued in a private offering exempt from the registration requirements of the Securities Act, to persons reasonably believed to be qualified institutional buyers in accordance with Rule 144A under the Securities Act and to persons outside the United States pursuant to Regulation S under the Securities Act, at a purchase price equal to 100% of the principal amount thereof. Prior to the conversion date, the First Lien Notes due May 2028 are secured on a super-priority basis and pari passu with the DIP Revolving Facility and the DIP Term Loan Facility, subject to permitted liens and certain exceptions, by all the assets that secure Frontier’s obligations under the DIP Revolving Facility and the DIP Term Loan Facility, on a super-priority basis and pari passu with the DIP Revolving Facility and the DIP Term Loan Facility. From the conversion date, the First Lien Notes due May 2028 are secured on a first-priority basis and pari passu with its senior secured credit facilities, subject to permitted liens and certain exceptions, by all the assets that secure Frontier’s obligations under its senior secured credit facilities on a first-priority basis and pari passu with its senior secured credit facilities. Frontier may redeem the First Lien Notes due May 2028 at any time, in whole or in part, prior to their maturity. If redeemed before May 1, 2024 the redemption price will be equal to 100% of the aggregate principal amount thereof, together with any accrued and unpaid interest, if any, to, but not including, the redemption date, plus a make-whole premium. If the notes are redeemed on or after May 1, 2024, the redemption price will be equal to the amounts set forth in the 2028 First Lien Indenture, together with any accrued and unpaid interest to the redemption date. In addition, at any time before May 1, 2024, Frontier may redeem up to 40 % of the First Lien Notes due May 2028 using the proceeds of certain equity offerings at a redemption price equal to 105.000 % of the aggregate principal amount thereof, together with any accrued and unpaid interest, if any, to, but not including, the redemption date. In the event of a change of control triggering event, each holder of the First Lien Notes due May 2028 will have the right to require Frontier to purchase the notes at a purchase price equal to 101 % of the principal amount of the First Lien Notes due May 2028, plus accrued and unpaid interest, if any, to, but not including, the date of repurchase. The 2028 First Lien Indenture contains customary negative covenants, subject to a number of important exceptions and qualifications, including, without limitation, covenants related to incurring additional debt and issuing preferred stock; incurring or creating liens; redeeming and/or prepaying certain debt; paying dividends on our stock or repurchasing stock; making certain investments; engaging in specified sales of assets; entering into transactions with affiliates; and engaging in consolidation, mergers and acquisitions. Certain of these covenants will be suspended during such time, if any, that the First Lien Notes due May 2028 have investment grade ratings by at least two of Moody’s, S&P or Fitch. The 2028 First Lien Indenture also provides for customary events of default which, if any of them occurs, would permit or require the principal of and accrued interest on the First Lien Notes due May 2028 to become or to be declared due and payable. New Second Lien Notes On November 25, 2020, Frontier issued $ 1,000 million aggregate principal amount of second lien secured notes that mature on May 1, 2029 , and bear interest at a rate of 6.750 % per annum (the New Second Lien Notes, and together with the First Lien Notes due October 2027 and the First Lien Notes due May 2028, the Secured Notes). Interest is payable to holders of record semi-annually in arrears on May 1 and November 1 of each year, commencing May 1, 2021. The New Second Lien Notes were issued pursuant to an indenture, dated as of November 25, 2020 (the New Second Lien Indenture, and together with the 2027 First Lien Indenture and the 2028 First Lien Indenture, the Secured Note Indentures), by and among Frontier, the guarantors party thereto, the grantor party thereto, Wilmington Trust, National Association, as trustee and collateral agent, and were issued in a private offering exempt from the registration requirements of the Securities Act, to persons reasonably believed to be qualified institutional buyers in accordance with Rule 144A under the Securities Act and to persons outside the United States pursuant to Regulation S under the Securities Act, at a purchase price equal to 100% of the principal amount thereof. Prior to the conversion date, the New Second Lien Notes are superpriority obligations secured by a second-priority lien junior to the DIP Revolving Facility, the DIP Term Loan Facility, the First Lien Notes due October 2027 and the First Lien Notes due May 2028 , subject to permitted liens and certain exceptions, by all the assets that secure Frontier’s obligations under the DIP Revolving Facility, the DIP Term Loan Facility, on a super-priority basis and pari passu with the DIP Revolving Facility and the DIP Term Loan Facility, the First Lien Notes due October 2027 and the First Lien Notes due May 2028 . From the conversion date, the New Second Lien Notes are secured on a second-priority basis junior to the DIP Revolving Facility, the First Lien Notes due October 2027 and the First Lien Notes due May 2028 , subject to permitted liens and certain exceptions, by all the assets that secure Frontier’s obligations under its senior secured credit facilities and existing first lien notes on a second-priority basis junior to its secured credit facilities and existing first lien notes. Frontier may redeem the New Second Lien Notes at any time, in whole or in part, prior to their maturity. If redeemed before May 1, 2024, the redemption price will be equal to 100% of the aggregate principal amount thereof, together with any accrued and unpaid interest, if any, to, but not including, the redemption date, plus a make-whole premium. If redeemed on or after May 1, 2024, the redemption price will be equal to the amounts set forth in the New Second Lien Indenture, together with any accrued and unpaid interest to the redemption date. In addition, at any time before November 1, 2023, Frontier may redeem up to 40 % of the New Second Lien Notes using the proceeds of certain equity offerings at a redemption price equal to 106.750 % of the aggregate principal amount thereof, together with any accrued and unpaid interest, if any, to, but not including, the redemption date. In the event of a change of control triggering event, each holder of the New Second Lien Notes will have the right to require Frontier to purchase the notes at a purchase price equal to 101 % of the principal amount of the New Second Lien Notes, plus accrued and unpaid interest, if any, to, but not including, the date of repurchase. The New Second Lien Indenture contains customary negative covenants, subject to a number of important exceptions and qualifications, including, without limitation, covenants related to incurring additional debt and issuing preferred stock; incurring or creating liens; redeeming and/or prepaying certain debt; paying dividends on our stock or repurchasing stock; making certain investments; engaging in specified sales of assets; entering into transactions with affiliates; and engaging in consolidation, mergers and acquisitions. Certain of these covenants will be suspended during such time, if any, that the New Second Lien Notes have investment grade ratings by at least two of Moody’s, S&P or Fitch. The New Second Lien Indenture also provides for customary events of default which, if any of them occurs, would permit or require the principal of and accrued interest on the New Second Lien Notes to become or to be declared due and payable. Repaid Original First Lien Notes On March 15, 2019, Frontier completed a private offering of $ 1,650 million aggregate principal amount of the Original First Lien Notes, which had a maturity date of April 1, 2027 , and accrued interest at a rate of 8.000 % per annum. As noted above, these notes were repaid in full using the proceeds from the October 8, 2020 debt refinancing. Repaid Original Second Lien Notes On March 19, 2018, Frontier completed a private offering of $ 1,600 million aggregate principal amount of the Original Second Lien Notes, which had a maturity date of April 1, 2026 , and accrued interest at a rate of 8.500 % per annum. As noted above, these notes were repaid in full using the proceeds from the November 25, 2020 debt refinancing. Repaid JP Morgan Credit Facilities Frontier had an amended and restated credit agreement with JPMorgan Chase Bank, N.A., as administrative agent, and the lenders party thereto, which provided for a $ 1,625 million senior secured Term Loan A facility (the Term Loan A), a $ 1,740 million Term Loan B, and the Revolver. As noted above all outstanding amounts remaining drawn under the Revolver and Term Loan B were fully repaid using cash on hand and the proceeds from the November 25, 2020 debt refinancing, and all outstanding amounts remaining drawn under Term Loan A were fully repaid using the proceeds from the offering of the Original First Lien Notes. On July 3, 2018, the Company entered into Increase Joinder No. 2 to the JPM Credit Agreement, pursuant to which the Company borrowed an incremental $ 240 million under the Term Loan B. The Company used the incremental borrowings to repay in full the 2014 CoBank Credit Agreement (as defined below), repay a portion of the 2016 CoBank Credit Agreement (as defined below) and pay certain fees and expenses related to this incremental borrowing. Repaid CoBank Credit Facilities Frontier had two separate credit agreements with CoBank, ACB, as administrative agent, lead arranger and a lender, and the other lenders, which provided for a $ 350 million senior term loan facility (the 2014 CoBank Agreement), and a $ 315 million senior term loan facility (the 2016 CoBank Credit Agreement). As noted above, all outstanding amounts remaining drawn under the 2016 CoBank Credit Agreement were repaid in full using the proceeds from the offering of the Original First Lien Notes, and all outstanding amounts remaining drawn under the 2014 CoBank Credit Agreement were repaid in full using the proceeds from the incremental borrowing provided by the Increased Joinder No. 2 to the JPM Credit Agreement. Repaid Unsecured Senior Notes For the year ended December 31, 2019, Frontier retired $ 348 million principal amount of 7.125 % senior unsecured notes due 2020 at maturity. For the year ended December 31, 2018, Frontier retired a $ 2,198 million aggregate principal amount of senior unsecured notes. As noted above, $ 1,651 million senior unsecured notes, consisting of $ 447 million of 8.500 % senior notes due 2020 , $ 249 million of 8.875 % senior notes due 2020 , $ 555 million of 6.250 % senior notes due 2021 , and $ 400 million of 9.250 % senior notes due 2021 , were paid prior to maturity using the proc

Restructuring And Other Charges

Restructuring And Other Charges	12 Months Ended
Restructuring And Other Charges	Dec. 31, 2020
Restructuring And Other Charges [Abstract]
Restructuring And Other Charges	(10) Restructuring and Other Charges: As of December 31, 2020, restructuring related liabilities of $ 2 million pertaining to employee separation charges and accrued costs related to transformation initiatives are included in “Other current liabilities” in our consolidated balance sheet. During 2018, Frontier announced a strategic plan (Transformation Program) with the objective of improving revenues, profitability, and cash flows by enhancing our operations and customer service and support processes. We had retained a consulting firm to assist in executing on various aspects of the Transformation Program. This agreement was terminated in June 2019 and in connection therewith we made subsequent payments of approximately $ 35 million related to previously accrued expenses. We continue to implement programs and initiatives designed to improve and enhance our business and expect associated expenses to be recognized as incurred. Amounts accrued in connection with related consulting arrangements are recognized as operating expense under “Restructuring costs and other charges.” Restructuring Costs During 2020, we incurred $ 87 million in expenses consisting of $ 8 million directly associated with transformation initiatives, $ 7 million of severance and employee costs resulting from workforce reductions, and $ 72 million of consulting and advisory costs related to our balance sheet restructuring activities through the Petition Date. Effective with the Petition date, these other charges consisting of consulting and advisory costs incurred are recorded in Reorganization items, net in the consolidated statement of operations. During 2019, we incurred $ 168 million in expenses related to changes in the operation of our business, consisting of $ 46 million directly associated with transformation initiatives, $ 44 million of pension/OPEB special termination benefit enhancements related to a voluntary severance program, $ 38 million of severance and employee costs resulting from workforce reductions, and $ 40 million of consulting and advisory costs related to our balance sheet restructuring activities, which are included in “Restructuring costs and other charges” in our consolidated statement of operations for the year ended December 31, 2019. During 2018, restructuring costs and other charges, primarily consisting of severance and other employee-related costs of $ 12 million and costs directly associated with the Transformation Program of $ 23 million, totaling $ 35 million in connection with workforce reductions, are included in “Restructuring costs and other charges” in our consolidated statement of operations for the year ended December 31, 2018. The following is a summary of the changes in the liabilities established for restructuring and related programs: Restructuring ($ in millions) Liability Balance at December 31, 2018 $ 18 Severance expense 38 Transformation costs 46 Other costs 40 Cash payments during the period ( 127 ) Balance at December 31, 2019 15 Severance expense 7 Transformation costs 8 Other costs 72 Cash payments during the period ( 100 ) Balance at December 31, 2020 $ 2

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2020
Leases [Abstract]
Leases	(( (11) Leases: With the adoption of ASC 842 on January 1, 2019, Frontier elected to apply the ‘package of practical expedients’, which permits the Company to not reassess under the new standard its prior conclusions including lease identification, lease classification, and initial direct costs. Additionally, Frontier elected to apply the land easement practical expedient, which permits the Company to account for land easements under the new standard only on a prospective basis. Frontier did not apply the use of hindsight practical expedient. The components of lease cost are as follows: For the year ended ( $ in millions ) December 31, 2020 December 31, 2019 Lease cost: Finance lease cost: Amortization of right-of-use assets $ 15 $ 19 Interest on lease liabilities 13 15 Finance lease cost 28 34 Operating lease cost (1) 68 79 Sublease income ( 11 ) ( 11 ) Total Lease cost $ 85 $ 102 (1) Includes short-term lease costs of $ 2 million and $ 3 million and variable lease costs of $ 6 million and $ 6 million for the years ended December 31, 2020 and 2019, respectively. Prior to adoption of ASC 842, pole-related rental expenses of $ 55 million for the year ended December 31, 2018, were included in lease expense. However, these agreements do not qualify as leases under ASC 842, so they are not included in the lease cost above. These agreements have been included in our purchase obligations table (see Note 22). Finance lease costs included in the above table, were excluded from rental expense in the years ended December 31, 2018, as they related to finance leases. Under ASC 840, rental expense for the year ended December 31, 2018 was $ 102 million. Supplemental balance sheet information related to leases is as follows: ( $ in millions ) December 31, 2020 December 31, 2019 Operating right-of-use assets $ 215 (1) $ 204 (1) Finance right-of-use assets $ 143 (2) $ 167 (2) Operating lease liabilities $ 223 (3) $ 211 (3) Finance lease liabilities $ 145 (4) $ 167 (4) Operating leases: Weighted-average remaining lease term 7.75 years 7.54 years Weighted-average discount rate 8.26 % 8.25 % Finance leases: Weighted-average remaining lease term 8.96 years 9.10 years Weighted-average discount rate 8.13 % 7.98 % (1) Operating ROU assets are included in Other assets on our consolidated balance sheet. (2) Finance ROU assets are included in Property, plant, and equipment on our December 31, 2020 consolidated balance sheets. (3) This amount represents $ 48 million and $ 44 million, and $ 175 million and $ 167 million, included in other current liabilities and other liabilities, respectively, on our December 31, 2020 and 2019 consolidated balance sheets. (4) This amount represents $ 21 million and $ 25 million, and $ 124 million and $ 142 million, included in other current liabilities and other liabilities, respectively, on our December 31, 2020 and 2019 consolidated balance sheets. Supplemental cash flow information related to leases is as follows: For the year ended ( $ in millions ) December 31, 2020 December 31, 2019 Cash paid for amount included in the measurement of lease liabilities, net of amounts received as revenue: Operating cash flows provided by operating leases $ 67 $ 70 Operating cash flows used by operating leases $ ( 68 ) $ ( 76 ) Operating cash flows used by finance leases $ ( 13 ) $ ( 15 ) Financing cash flows used by finance leases $ ( 23 ) $ ( 35 ) Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 28 $ 42 Finance leases $ 3 $ 34 Lessee For lessee agreements, Frontier elected to apply the short-term lease recognition exemption for all leases that qualify and as such, does not recognize assets or liabilities for leases with terms of less than twelve months, including existing leases at transition. Frontier elected not to separate lease and non-lease components. As of January 1, 2019, Frontier has operating and finance leases for administrative and network properties, vehicles, and certain equipment. Our leases have remaining lease terms of 1 year to 87 years, some of which include options to extend the leases, and some of which include options to terminate the leases within 1 year. The following represents a maturity analysis for our operating and finance lease liabilities as of December 31, 2020: Operating Finance ( $ in millions ) Leases Leases Future maturities: 2021 $ 49 $ 32 2022 47 27 2023 42 23 2024 38 16 2025 32 14 Thereafter 87 82 Total lease payments 295 194 Less: imputed interest ( 72 ) ( 49 ) Present value of lease liabilities $ 223 $ 145 (2) Upon adoption of ASC 842 on January 1, 2019, we recorded the unamortized deferred gain balances for previous sale-leasebacks of real estate assets as a transition adjustment, which had the effect of increasing our accumulated deficit by $ 15 million ($ 11 million net of tax). Lessor Frontier is the lessor for operating leases of towers, datacenters, corporate offices, and certain equipment. Our leases have remaining lease terms of 1 year to 65 years, some of which include options to extend the leases, and some of which include options to terminate the leases within 1 year. None of these leases include options for our lessees to purchase the underlying asset. A significant number of Frontier’s service contracts with its customers include equipment rentals. The Company has elected to apply the practical expedient to account for those associated equipment rentals and services as a single, combined component. We have evaluated the service component to be ‘predominant’ in these contracts and have accounted for the combined component as a single performance obligation under ASC 606. For the years ended December 31, 2020 and 2019, Frontier, as a lessor, recognized revenue of $ 67 million and $ 70 million, respectively. The following represents a maturity analysis for our future operating lease payments from customers as of December 31, 2020: Operating ( $ in millions ) Lease Payments Future maturities of lease payments from customers: 2021 $ 10 2022 10 2023 10 2024 7 2025 1 Thereafter 1 Total lease payments from customers $ 39

Investment And Other Income (Lo

Investment And Other Income (Loss), Net	12 Months Ended
Investment And Other Income (Loss), Net	Dec. 31, 2020
Investment And Other Income (Loss), Net [Abstract]
Investment And Other Income (Loss), Net	(12) Investment and Other Income (Loss), Net : The components of investment and other income (loss), net for the years ended December 31, 2020, 2019 and 2018 are as follows: For the year ended December 31, ( $ in millions ) 2020 2019 2018 Interest and dividend income $ 4 $ 9 $ 6 Pension and OPEB benefit (costs) ( 43 ) ( 42 ) 10 All other, net ( 4 ) ( 4 ) ( 3 ) Total investment and other income (loss), net $ ( 43 ) $ ( 37 ) $ 13 Pension and OPEB benefit (costs) included in “Investment and other income, net” on our consolidated statements of operations, represent the non-service cost components of pension and other post-retirement benefit (OPEB) costs. Service cost components of pension and OPEB benefit costs are included in “Network related expense” and “Selling, general, and administrative expenses on our consolidated statements of operations.

Capital Stock

Capital Stock	12 Months Ended
Capital Stock	Dec. 31, 2020
Capital Stock [Abstract]
Capital Stock	(13) Capital Stock : As of December 31, 2020, Frontier has approximately 175 million, 106 million, and 105 million shares of common stock authorized, issued, and outstanding, respectively. Additionally, Frontier has no shares of preferred stock issued and outstanding as of December 31, 2020 or 2019. Mandatory Convertible Preferred Stock (Series A) On June 29, 2018, all outstanding shares of Frontier’s 11.125 % Mandatory Convertible Preferred Stock, Series A, par value $ 0.01 per share (the Series A Preferred Stock) converted at a rate of 1.3333 common shares per share of preferred stock into an aggregate of approximately 25,529,000 shares (net of fractional shares) of the Company’s common stock, pursuant to the terms of the Certificate of Designation governing the Series A Preferred Stock. Frontier issued cash in lieu of fractional shares of common stock in the conversion. These payments were recorded as a reduction to Additional paid-in capital. The final dividend of $ 54 million was paid on July 2, 2018. The Series A Preferred Stock was issued in June 2015 when we completed a registered offering of 19.25 million preferred shares at an offering price of $ 100 per share. Aggregate net proceeds of the offering were $ 1,866 million after deducting commissions and estimated expenses. We used the net proceeds from this offering to fund a portion of the acquisition price of the CTF Acquisition and related fees and expenses.

Stock Plans

Stock Plans	12 Months Ended
Stock Plans	Dec. 31, 2020
Stock Plans [Abstract]
Stock Plans	(14) Stock Plans : At December 31, 2020, we have four stock-based compensation plans under which grants were made and awards remained outstanding. No further awards may be granted under three of the plans: the 2013 Equity Incentive Plan (the 2013 EIP), the Deferred Fee Plan and the Directors’ Equity Plan. At December 31, 2020, there were approximately 5,667,000 shares authorized for grant and approximately 3,632,000 shares available for grant under the 2017 Equity Incentive Plan (the 2017 EIP together with the 2013 EIP (the EIPs). Our general policy is to issue treasury shares upon the grant of restricted shares and the exercise of options. 2013 and 2017 Equity Incentive Plans Since the expiration date of the 2013 EIP on May 10, 2017, no awards have been or may be granted under such plan. Under the 2017 EIP, awards of our common stock may be granted to eligible employees in the form of incentive stock options, non-qualified stock options, SARs, restricted stock, performance shares or other stock-based awards. As discussed under the Non-Employee Directors’ Compensation Plans below, prior to May 25, 2006, non-employee directors received an award of stock options upon commencement of service. No awards may be granted more than 10 years after the effective date (May 10, 2017) of the 2017 EIP plan. The exercise price of stock options and SARs under the EIPs generally are equal to or greater than the fair market value of the underlying common stock on the date of grant. Stock options are not ordinarily exercisable on the date of grant but vest over a period of time (generally four years ). Under the terms of the EIPs, subsequent stock dividends and stock splits have the effect of increasing the option shares outstanding, which correspondingly decrease the average exercise price of outstanding options. Performance Shares/Units On February 15, 2012, Frontier’s Compensation Committee, adopted the Frontier Long-Term Incentive Plan (the LTIP). LTIP awards were granted in the form of performance shares or units/cash. The LTIP was offered under the EIPs, and participants consist of senior vice presidents and above. The LTIP awards had performance, market and time-vesting conditions. During the first 90 days of a three year performance period (a Measurement Period), a target number of performance shares or units were awarded to each LTIP participant with respect to the Measurement Period. The performance metrics under the LTIP were (1) annual targets for operating cash flow or adjusted free cash flow per share based on the goal set and (2) an overall performance “modifier, based on Frontier’s total return to stockholders (i.e., Total Shareholder Return or TSR) relative to the Integrated Telecommunications Services Group (GICS Code 50101020) for the Measurement Period. Operating cash flow or adjusted free cash flow per share performance was determined at the end of each year and the annual results were averaged at the end of the Measurement Period to determine the preliminary number of shares earned under the LTIP award. The TSR performance measure was then applied to decrease or increase payouts based on Frontier’s three year relative TSR performance. LTIP awards, to the extent earned, were paid out in the form of common stock or cash shortly following the end of the Measurement Period. During 2020, all of the remaining performance shares under the LTIP were cancelled. The following summary presents information regarding LTIP target performance shares as of December 31, 2020 and changes during the three years then ended with regard to LTIP shares: Number of Shares (in thousands) Balance at December 31, 2017 306 LTIP target performance shares granted 284 LTIP target performance shares earned ( 18 ) LTIP target performance shares forfeited ( 75 ) Balance at December 31, 2018 497 LTIP target performance shares granted - LTIP target performance shares earned ( 381 ) LTIP target performance shares forfeited ( 20 ) Balance at December 31, 2019 96 LTIP target performance shares/units granted - LTIP target performance shares/units earned - LTIP target performance shares/units forfeited ( 96 ) Balance at December 31, 2020 - For purposes of determining compensation expense, the fair value of each performance share was measured at the end of each reporting period and, therefore, fluctuated based on the price of Frontier common stock as well as performance relative to the targets. Frontier recognized an expense, included in “Selling, general, and administrative expenses” of $ 0 million, $ 4 million, and $ 5 million during 2020, 2019 and 2018, respectively, for the LTIP. Restricted Stock The following summary presents information regarding unvested restricted stock as of December 31, 2020 and changes during the three years then ended with regard to restricted stock under the 2017 EIP: Weighted Average Number of Grant Date Aggregate Shares Fair Value Fair Value (in thousands) (per share) (in millions) Balance at December 31, 2017 633 $ 58.63 $ 4 Restricted stock granted 2,023 $ 8.26 $ 5 Restricted stock vested ( 221 ) $ 66.82 $ ( 1 ) Restricted stock forfeited ( 577 ) $ 16.47 Balance at December 31, 2018 1,858 $ 16.02 $ 4 Restricted stock granted 105 $ 2.00 $ - Restricted stock vested ( 1,039 ) $ 19.05 $ ( 1 ) Restricted stock forfeited ( 24 ) $ 28.30 Balance at December 31, 2019 900 $ 10.57 $ 1 Restricted stock granted - $ 0.00 $ - Restricted stock vested ( 387 ) $ 15.04 $ - Restricted stock forfeited ( 209 ) $ 7.79 Balance at December 31, 2020 304 $ 6.78 $ - For purposes of determining compensation expense, the fair value of each restricted stock grant is estimated based on the average of the high and low market price of a share of our common stock on the date of grant. Total remaining unrecognized compensation cost associated with unvested restricted stock awards that is deferred at December 31, 2020 was less than $ 1 million and the weighted average vesting period over which this cost is expected to be recognized is less than 1 year. We have granted restricted stock awards to employees in the form of our common stock. None of the restricted stock awards may be sold, assigned, pledged or otherwise transferred, voluntarily or involuntarily, by the employees until the restrictions lapse, subject to limited exceptions. The restrictions are time-based. Compensation expense, recognized in “Selling, general and administrative expenses”, of $ 2 million, $ 11 million and $ 13 million for the years ended December 31, 2020, 2019 and 2018, respectively, has been recorded in connection with these grants. Non-Employee Directors’ Compensation Plans Beginning October 1, 2013, stock units were credited to the director’s account in an amount that was determined as follows: the total cash value of the fees payable to the director is divided by the closing price of Frontier common stock on the grant date of the units. Units were credited to the director’s account quarterly. Directors must also elect to convert the units to cash upon retirement or death. There were 8 directors participating in the Director Plans during all or part of 2020. The total plan units earned were 0 , 155,045 and 183,791 in 2020, 2019, and 2018, respectively. As of June 2019, no further stock units have been issued to Non-Employee Directors. Since the directors had the option to receive distributions from their stock units in cash, they were considered liability-based awards. Prior to adoption of ASU 2018-07, “Compensation – Stock Compensation (ASC 718): Improvements to Non-employee Share-Based payment accounting;” compensation expense was based on the current market value of our common stock at each reporting date. Upon adoption, compensation expense for all unvested awards was based on the market value of our common stock at the date of adoption and compensation expense for awards granted following adoption were based on the market value of our common stock at the grant date for each award. In connection with the Director Plans, there were compensation costs associated with the issuance of stock units of $ 1 million in 2019 and $( 1 ) million in 2018. Cash compensation associated with the Director Plans was $ 5 million in 2020, $ 4 million in 2019 and $ 1 million in 2018. These costs are recognized in “Selling, general and administrative expenses”.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2020
Income Taxes [Abstract]
Income Taxes	(15) Income Taxes : The following is a reconciliation of the provision for income taxes computed at the federal statutory rate to income taxes computed at the effective rates for the years ended December 31, 2020, 2019 and 2018: 2020 2019 2018 Consolidated tax provision at federal statutory rate 21.0 % 21.0 % 21.0 % State income tax provisions, net of federal income tax benefit 21.7 2.6 1.6 Tax reserve adjustment ( 0.7 ) - 0.1 Changes in certain deferred tax balances ( 35.8 ) ( 2.3 ) ( 3.5 ) Interest expense deduction 30.7 - - Restructuring cost ( 10.0 ) - - Goodwill impairment - ( 11.8 ) ( 10.4 ) Loss on disposal of Northwest Operations ( 9.1 ) - - Share-based payments ( 0.2 ) ( 0.1 ) ( 0.5 ) Federal research and development credit ( 0.5 ) - 0.1 Deferred Tax Remeasurement - 2017 Tax Reform - - 0.6 All other, net 0.1 - ( 0.2 ) Effective tax rate 17.2 % 9.4 % 8.8 % CARES Act On March 27, 2020, the CARES Act were each enacted in response to the COVID-19 pandemic. The CARES Act contains numerous income tax provisions, such as relaxing limitations on the deductibility of interest and the use of net operating losses arising in taxable years beginning after December 31, 2017. The CARES Act has a number of beneficial tax provisions (e.g., deferral of the employer portion of social security taxes for the remainder of 2020, the ability to claim additional interest deductions, net operating loss carrybacks, and removal of the 80 % usage limitation for post-2017 NOLs for tax years 2018, 2019 and 2020). Employers can defer payment of the employer’s share of the Social Security tax that they otherwise are responsible for paying on wages. The deferral applies to affected taxes normally required to be paid from March 27, 2020, through December 31, 2020. The deferred tax must be paid over the following two years , with half to be paid by December 31, 2021, and the other half to be paid by December 31, 2022. As of December 31, 2020, Frontier has entered the program and has deferred approximately the payment of $ 60 million. The business interest deduction limit under Code Sec. 163(j) is increased to 50 percent of the taxpayer’s adjusted taxable income (ATI) for the 2019 and 2020 tax years. A taxpayer may also elect for the 2020 year only to use 2019 ATI in calculating the limitation. A taxpayer may elect not to have the increased limitation apply in 2019 or 2020. Net operating losses (NOLs) arising in tax years beginning in 2018, 2019, and 2020 now have a five-year carryback period and an unlimited carryforward period. The provision limiting an NOL deduction attributable to NOLs arising in tax years beginning after 2017 to 80 percent of taxable income does not apply during these years. The Tax Cut and Jobs Act On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly known as the Tax Cut and Jobs Act (the TCJA). The TCJA, makes broad and complex changes to the U.S. tax code. The TCJA reduces the corporate tax rate to 21 %, effective January 1, 2018. Under ASC 740, the effects of new legislation are recognized upon enactment. Accordingly, recognition of the tax effects of the TCJA were required in the interim and annual periods that include December 22, 2017. On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (SAB 118), which allowed the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. As a result, the Company previously provided provisional estimates of the effect of the TCJA in the financial statements. In the fourth quarter of 2018, the Company completed our analysis to determine the effects of the TCJA and recorded immaterial adjustments as of December 31, 2018. Shareholders’ Rights Agreement On July 1, 2019, the Board of Directors of Frontier Communications adopted a shareholder’s right plan (Rights Agreement) designed to protect the availability of the net operating loss carryforwards under the Internal Revenue Code (IRC). The Rights Agreement is intended to reduce the likelihood of an ownership change under Section 382 of the IRC by deterring any person or group of affiliated or associated persons from acquiring beneficial ownership of 4.9 % or more of the outstanding common shares. Other Tax Items Income taxes includes the tax impact of $ 524 million and $ 72 million, related to the goodwill impairment for the years ended December 31, 2019 and 2018, respectively. As of December 31, 2020, $ 13 million of expected income tax refunds are included in “Income taxes and other current assets” in the consolidated balance sheet. In 2020, 2019 and 2018, we paid net federal and state income tax totaling $ 8 million, $ 4 million, and $ 4 million, respectively. The components of the net deferred income tax liability (asset) at December 31 are as follows: ( $ in millions ) 2020 2019 Deferred income tax liabilities: Property, plant and equipment basis differences $ 1,873 $ 2,184 Deferred revenue/expense 44 65 Other, net 56 56 $ 1,973 $ 2,305 Deferred income tax assets: Pension liability $ 308 $ 256 Intangibles 681 665 Tax operating loss carryforward 923 898 Employee benefits 207 184 Interest expense deduction limitation carryforward 44 238 Accrued expenses 75 37 Lease obligations 83 92 Tax credit 40 39 Allowance for doubtful accounts 35 32 Other, net 17 7 2,413 2,448 Less: Valuation allowance ( 783 ) ( 605 ) Net deferred income tax asset 1,630 1,843 Net deferred income tax liability $ 343 $ 462 Our federal net operating loss carryforward as of December 31, 2020 is estimated at $ 1.8 billion. The majority of the federal loss carryforward will begin to expire after 2036 , with $ 121 million carrying forward indefinitely, unless otherwise used. In connection with the sale of the Northwest Operations, Frontier utilized NOL’s of approximately $ 857 million during the year ended December 31, 2020. Our state tax operating loss carryforward as of December 31, 2020 is estimated at $ 9.4 billion. A portion of our state loss carryforward will continue to expire annually through 2039 , unless otherwise used. Our federal research and development credit as of December 31, 2020 is estimated at $ 12 million. The federal research and development credit will expire between 2034 and 2039 , unless otherwise used. Our various state credits as of December 31, 2020 are estimated at $ 34 million. The state credits will expire between 2020 and 2023 , unless otherwise used. As of December 31, 2020, Frontier has a valuation allowance of $ 783 million to reduce deferred tax assets to an amount more likely than not to be realized. This valuation allowance is related to state net operating losses, state tax credits, and the state impact from the federal limitation on interest expense deduction. In evaluating Frontier’s ability to realize its deferred tax assets, management considers whether it is more likely than not that some or all of the deferred tax assets will not be realized. Management also considered the projected reversal of deferred tax liabilities and projected future taxable income in making this assessment. Based upon this assessment, management believes it is more likely than not Frontier will realize the benefits of these deductible differences, net of valuation allowance. The provision (benefit) for federal and state income taxes, as well as the taxes charged or credited to equity of Frontier, includes amounts both payable currently and deferred for payment in future periods as indicated below: ( $ in millions ) 2020 2019 2018 Income tax expense (benefit): Current: Federal $ ( 12 ) $ 1 $ ( 1 ) State 19 7 6 Total Current 7 8 5 Deferred: Federal ( 84 ) ( 606 ) ( 77 ) State ( 7 ) ( 13 ) 10 Total Deferred ( 91 ) ( 619 ) ( 67 ) Total income tax benefit ( 84 ) ( 611 ) ( 62 ) Income taxes charged (credited) to equity of Frontier: Deferred income taxes (benefits) arising from the recognition of additional pension/OPEB liability 35 32 ( 31 ) Total income taxes charged (credited) to equity of Frontier 35 32 ( 31 ) Total income tax benefit $ ( 49 ) $ ( 579 ) $ ( 93 ) U.S. GAAP requires applying a “more likely than not” threshold to the recognition and derecognition of uncertain tax positions either taken or expected to be taken in Frontier’s income tax returns. The total amount of our gross tax liability for tax positions that may not be sustained under a “more likely than not” threshold amounts to $ 16 million as of December 31, 2020, including immaterial interest. The amount of our uncertain tax positions, for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease during the next twelve months, and which would affect our effective tax rate, is $ 2 million as of December 31, 2020. Frontier’s policy regarding the classification of interest and penalties is to include these amounts as a component of income tax expense. This treatment of interest and penalties is consistent with prior periods. We are subject to income tax examinations generally for the years 2017 forward for federal and 2016 forward for state filing jurisdictions. We also maintain uncertain tax positions in various state jurisdictions. The following table sets forth the changes in Frontier’s balance of unrecognized tax benefits for the years ended December 31, 2019 and 2018: ($ in millions) 2020 2019 Unrecognized tax benefits - beginning of year $ 12 $ 11 Gross increases - prior year tax positions 4 - Gross increases - current year tax positions - 1 Gross decreases - FIN 48 liability release - - Gross decreases - expired statute of limitations - - Unrecognized tax benefits - end of year $ 16 $ 12

Net Loss Per Common Share

Net Loss Per Common Share	12 Months Ended
Net Loss Per Common Share	Dec. 31, 2020
Net Loss Per Common Share [Abstract]
Net Loss Per Common Share	(16) Net Loss Per Common Share : The reconciliation of the net loss per common share calculation for the years ended December 31, 2020, 2019 and 2018 is as follows: ( $ in millions and shares in thousands, except per share amounts ) 2020 2019 2018 Net loss used for basic and diluted earnings (loss) per share: Net loss attributable to Frontier common shareholders $ ( 402 ) $ ( 5,911 ) $ ( 750 ) Less: Dividends paid on unvested restricted stock awards - - - Total basic net loss attributable to Frontier common shareholders $ ( 402 ) $ ( 5,911 ) $ ( 750 ) Effect of loss related to dilutive stock units - - - Total diluted net loss attributable to Frontier common shareholders $ ( 402 ) $ ( 5,911 ) $ ( 750 ) Basic earnings (loss) per share: Total weighted average shares and unvested restricted stock awards outstanding - basic 104,944 105,356 91,523 Less: Weighted average unvested restricted stock awards ( 477 ) ( 1,291 ) ( 1,840 ) Total weighted average shares outstanding - basic 104,467 104,065 89,683 Basic net loss per share attributable to Frontier common shareholders $ ( 3.85 ) $ ( 56.80 ) $ ( 8.37 ) Diluted earnings (loss) per share: Total weighted average shares outstanding - basic 104,467 104,065 89,683 Effect of dilutive shares - - - Total weighted average shares outstanding - diluted 104,467 104,065 89,683 Diluted net loss per share attributable to Frontier common shareholders $ ( 3.85 ) $ ( 56.80 ) $ ( 8.37 ) In calculating diluted net loss per common share for the years ended December 31, 2020, 2019 and 2018 the effect of all common stock equivalents is excluded from the computation as the effect would be antidilutive. Stock Options For the year ended December 31, 2020, there were no outstanding stock options. For each of the years ended December 31, 2019 and 2018, options to purchase 1,334 shares, issuable under employee compensation plans were excluded from the computation of diluted earnings (loss) per share (EPS) for those periods because the exercise prices were greater than the average market price of our common stock and, therefore, the effect would be antidilutive. Stock Units At December 31, 2020, 2019 and 2018, we had 339,544 , 339,544 and 348,093 stock units, respectively, issued under the Director Plans and the 2013 EIP. These securities have not been included in the diluted income per share of common stock calculation because their inclusion would have an antidilutive effect.

Comprehensive Loss

Comprehensive Loss	12 Months Ended
Comprehensive Loss	Dec. 31, 2020
Comprehensive Loss [Abstract]
Comprehensive Loss	(17) Comprehensive Loss : Comprehensive income (loss) consists of net income (loss) and other gains and losses affecting shareholders’ equity (deficit) and pension/postretirement benefit (OPEB) liabilities that, under GAAP, are excluded from net income (loss). The components of accumulated other comprehensive income (loss), net of tax, as of December 31, 2020, 2019 and 2018 and changes for the years then ended, are as follows: ($ in millions) Pension Costs OPEB Costs Total Balance at December 31, 2017 (1) $ ( 345 ) $ ( 21 ) $ ( 366 ) Other comprehensive income (loss) before reclassifications ( 191 ) 51 ( 140 ) Amounts reclassified from accumulated other comprehensive income (loss) 47 ( 4 ) 43 Net current-period other comprehensive income (loss) ( 144 ) 47 ( 97 ) Balance at December 31, 2018 (1) ( 489 ) 26 ( 463 ) Other comprehensive income (loss) before reclassifications ( 201 ) 17 ( 184 ) Amounts reclassified from accumulated other comprehensive income (loss) 89 ( 13 ) 76 Net current-period other comprehensive income (loss) ( 112 ) 4 ( 108 ) Impact of adoption of ASU 2018-02 ( 83 ) 4 ( 79 ) Balance at December 31, 2019 (1) ( 684 ) $ 34 $ ( 650 ) Other comprehensive income (loss) before reclassifications ( 320 ) ( 76 ) ( 396 ) Amounts reclassified from accumulated other comprehensive income (loss) 305 ( 14 ) 291 Net current-period other comprehensive income (loss) ( 15 ) ( 90 ) ( 105 ) Balance at December 31, 2020 (1) $ ( 699 ) $ ( 56 ) $ ( 755 ) (1) Pension and OPEB amounts are net of deferred tax balances of $ 234 million, $ 204 million, $ 250 million and $ 223 million as of December 31, 2020, 2019, 2018, and 2017, respectively. As a result of the pension settlement accounting discussed in Note 20, Frontier recorded pension settlement charges totaling $ 159 million ($ 122 million net of tax), $ 57 million ($ 43 million net of tax), and $ 41 million ($ 31 million net of tax), which were reclassified from accumulated Other comprehensive income (loss) during 2020, 2019 and 2018, respectively. The significant items reclassified from each component of accumulated other comprehensive loss for the years ended December 31, 2020, 2019 and 2018 are as follows: Amount Reclassified from ($ in millions) Accumulated Other Comprehensive Loss (1) Affected Line Item in the Details about Accumulated Other Statement where Comprehensive Loss Components 2020 2019 2018 Net loss is Presented Amortization of Pension Cost Items (2) Actuarial gains (losses) $ ( 99 ) $ ( 58 ) $ ( 24 ) Loss on disposal ( 81 ) - - Pension settlement costs ( 159 ) ( 57 ) ( 41 ) Reclassifications, pretax ( 339 ) ( 115 ) ( 65 ) Loss before income taxes Tax Impact 34 26 18 Income tax (expense) benefit Reclassifications, net of tax $ ( 305 ) $ ( 89 ) $ ( 47 ) Net loss Amortization of OPEB Cost Items (2) Prior-service credits (costs) $ 32 $ 11 $ 9 Actuarial gains (losses) ( 6 ) 4 ( 3 ) Loss on disposal ( 7 ) - - Reclassifications, pretax 19 15 6 Loss before income taxes Tax impact ( 5 ) ( 2 ) ( 2 ) Income tax (expense) benefit Reclassifications, net of tax $ 14 $ 13 $ 4 Net loss (1) Amounts in parentheses indicate losses. (2) These accumulated other comprehensive loss components are included in the computation of net periodic pension and OPEB costs (see Note 20 - Retirement Plans for additional details).

Segment Information

Segment Information	12 Months Ended
Segment Information	Dec. 31, 2020
Segment Information [Abstract]
Segment Information	(18) Segment Information : We operate in one operating and one reportable segment. Frontier provides both regulated and unregulated voice, data and video services to consumer and commercial customers and is typically the incumbent voice services provider in its service areas.

Quarterly Financial Data

Quarterly Financial Data	12 Months Ended
Quarterly Financial Data	Dec. 31, 2020
Quarterly Financial Data [Abstract]
Quarterly Financial Data	(19) Quarterly Financial Data (Unaudited) : 2020 First Second Third Fourth Total ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year Revenue $ 1,933 $ 1,801 $ 1,726 $ 1,695 $ 7,155 Operating income (3) $ 272 $ 140 $ 270 $ 277 $ 959 Net earnings (loss) attributable to Frontier common shareholders (2)(3) $ ( 186 ) $ ( 181 ) $ 15 $ ( 50 ) $ ( 402 ) Basic and diluted net earnings (loss) per share attributable to Frontier common shareholders (1)(2)(3) $ ( 1.78 ) $ ( 1.73 ) $ 0.14 $ ( 0.48 ) $ ( 3.85 ) (1) The quarterly net loss per share amounts are rounded to the nearest cent. Annual net loss per share may vary depending on the effect of such rounding. (2) During 2020, Frontier recorded $ 409 million in reorganization items, net ($ 361 million net of tax) in connection with the Restructuring Plan. (3) During 2020, we recorded aggregate losses on the disposal of our Northwest Operations of $ 162 million ($ 118 million after-tax). Refer to Note 7 for further details 2019 First Second Third Fourth Total ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year Revenue (3) $ 2,101 $ 2,067 $ 1,997 $ 1,942 $ 8,107 Operating income (loss) (2)(3) $ 339 $ ( 5,459 ) $ 26 $ 221 $ ( 4,873 ) Net loss attributable to Frontier common shareholders (2)(3) $ ( 87 ) $ ( 5,317 ) $ ( 345 ) $ ( 162 ) $ ( 5,911 ) Basic and diluted net loss per share attributable to Frontier common shareholders (1)(2)(3) $ ( 0.84 ) $ ( 51.07 ) $ ( 3.31 ) $ ( 1.55 ) $ ( 56.80 ) (1) The quarterly net loss per share amounts are rounded to the nearest cent. Annual net loss per share may vary depending on the effect of such rounding. (2) During 2019, we recorded aggregate goodwill impairment charges of $ 5,725 million ($ 5,201 million after-tax). Refer to Note 8 for further details. (3) During 2019, we recorded aggregate losses on the disposal of our Northwest Operations of $ 446 million ($ 446 million after-tax). Refer to Note 7 for further details.

Retirement Plans

Retirement Plans	12 Months Ended
Retirement Plans	Dec. 31, 2020
Retirement Plans [Abstract]
Retirement Plans	(20) Retirement Plans : We sponsor a noncontributory defined benefit pension plan covering a significant number of our former and current employees and other postretirement benefit plans that provide medical, dental, life insurance and other benefits for covered retired employees and their beneficiaries and covered dependents. The pension plan and postretirement benefit plans are closed to the majority of our newly hired employees. The benefits are based on years of service and final average pay or career average pay. Contributions are made in amounts sufficient to meet ERISA funding requirements while considering tax deductibility. Plan assets are invested in a diversified portfolio of equity and fixed-income securities and alternative investments. The accounting results for pension and other postretirement benefit costs and obligations are dependent upon various actuarial assumptions applied in the determination of such amounts. These actuarial assumptions include the following: discount rates, expected long-term rate of return on plan assets, future compensation increases, employee turnover, healthcare cost trend rates, expected retirement age, optional form of benefit and mortality. We review these assumptions for changes annually with our independent actuaries. We consider our discount rate and expected long-term rate of return on plan assets to be our most critical assumptions. The discount rate is used to value, on a present value basis, our pension and other postretirement benefit obligations as of the balance sheet date. The same rate is also used in the interest cost component of the pension and postretirement benefit cost determination for the following year. The measurement date used in the selection of our discount rate is the balance sheet date. Our discount rate assumption is determined annually with assistance from our independent actuaries based on the pattern of expected future benefit payments and the prevailing rates available on long-term, high quality corporate bonds that approximate the benefit obligation. As of December 31, 2020, 2019 and 2018, we utilized an estimation technique that is based upon a settlement model (Bond:Link) that permits us to closely match cash flows to the expected payments to participants. This rate can change from year-to-year based on market conditions that affect corporate bond yields. As a result of the technique described above, Frontier is utilizing a discount rate of 2.60 % as of December 31, 2020 for its qualified pension plan, compared to rates of 3.40 % and 4.30 % in 2019 and 2018, respectively. The discount rate for postretirement plans as of December 31, 2020 was a range of 2.60 % to 2.80 % compared to a range of 3.40 % to 3.50 % in 2019 and 4.30 % to 4.40 % in 2018. The pension plan contains provisions that provide certain employees with the option of receiving a lump sum payment upon retirement. Frontier’s accounting policy is to record these payments as a settlement only if, in the aggregate, they exceed the sum of the annual service and interest costs for the Pension Plan’s net periodic pension benefit cost. During year ended December 31, 2020, lump sum pension settlement payments to terminated or retired individuals amounted to $ 465 million, which exceeded the settlement threshold of $ 211 million, and as a result, Frontier recognized non-cash settlement charges totaling $ 159 million during 2020. The non-cash charge accelerated the recognition of a portion of the previously unrecognized actuarial losses in the Pension Plan. These non-cash charges increased our recorded net loss and accumulated deficit, with an offset to accumulated other comprehensive loss in shareholders’ equity. Frontier recognized non-cash settlement charges totaling $ 57 million and $ 41 million during 2019 and 2018, respectively. During 2019, the Company recognized a charge of $ 44 million to reflect the cost of pension/OPEB special termination benefit enhancements related to a voluntary severance program . Our pension plan assets decreased from $ 2,730 million at December 31, 2019 to $ 2,507 million at December 31, 2020, a decrease of $ 223 million, or 8 %. This decrease was primarily a result of benefit payments of $ 538 million and the impact of the sale of the Northwest Operations of $ 70 million, partially offset by contributions of $ 64 million and investment returns of $ 321 million, net of investment management expenses and other expenses. The expected long-term rate of return on plan assets is applied in the determination of periodic pension and postretirement benefit cost as a reduction in the computation of the expense. In developing the expected long-term rate of return assumption, we considered published surveys of expected market returns, 10 and 20 year actual returns of various major indices, and our own historical 5 year, 10 year and 20 year investment returns. The expected long-term rate of return on plan assets is based on an asset allocation assumption of 40 % in long-duration fixed income securities, and 60 % in equity securities and other investments. We review our asset allocation at least annually and make changes when considered appropriate. Our pension asset investment allocation decisions are made by the Retirement Investment & Administration Committee (RIAC), a committee comprised of members of management, pursuant to a delegation of authority by the Board of Directors. Asset allocation decisions take into account expected market return assumptions of various asset classes as well as expected pension benefit payment streams. When analyzing anticipated benefit payments, management considers both the absolute amount of the payments as well as the timing of such payments. Our expected long-term rate of return on plan assets was 7.50 % in 2020 and 2019. For 2021, we expect to assume a rate of return of 7.50 %. Our pension plan assets are valued at fair value as of the measurement date. The measurement date used to determine pension and other postretirement benefit measures for the pension plan and the postretirement benefit plan is December 31. The remeasured funded status of the pension plan was approximately 68 %, as of December 31, 2020. Pension Benefits The following tables set forth the pension plan’s projected benefit obligations, fair values of plan assets and the pension benefit liability recognized on our consolidated balance sheets as of December 31, 2020 and 2019 and the components of total pension benefit cost for the years ended December 31, 2020, 2019 and 2018. The below tables include all investment activity related to assets and obligations that were transferred in connection with the planned divestiture of our Northwest Operations: ( $ in millions ) 2020 2019 Change in projected benefit obligation (PBO) PBO at beginning of year $ 3,726 $ 3,173 Service cost 95 82 Interest cost 108 130 Actuarial (gain) loss 506 603 Benefits paid ( 73 ) ( 65 ) Impact of Divestiture of Northwest Operations (1) ( 189 ) - Settlements ( 465 ) ( 235 ) Special termination benefits - 38 PBO at end of year $ 3,708 $ 3,726 Change in plan assets Fair value of plan assets at beginning of year $ 2,730 $ 2,348 Fair value of plan assets for the Northwest Operations ( 70 ) - Actual return on plan assets 321 516 Employer contributions 64 166 Settlements ( 465 ) ( 235 ) Benefits paid ( 73 ) ( 65 ) Fair value of plan assets at end of year $ 2,507 $ 2,730 Funded status $ ( 1,201 ) $ ( 996 ) Amounts recognized in the consolidated balance sheet Pension and other postretirement benefits - current $ - $ - Pension and other postretirement benefits - noncurrent $ ( 1,201 ) $ ( 996 ) Accumulated other comprehensive loss $ 915 $ 899 (1) Includes a gain of $ 20 million related to the elimination of future compensation increases as a result of the divestiture of the Northwest Operations. ( $ in millions ) 2020 2019 2018 Components of total pension benefit cost Service cost $ 95 $ 82 $ 90 Interest cost on projected benefit obligation 108 130 125 Expected return on plan assets ( 171 ) ( 172 ) ( 192 ) Amortization of unrecognized loss 99 58 24 Net periodic pension benefit cost 131 98 47 Pension settlement costs 159 57 41 Pension special termination benefit enhancements - 38 - Gain on disposal, net ( 38 ) - - Total pension benefit cost $ 252 $ 193 $ 88 During the year ended December 31, 2020, Frontier recorded aggregate pension settlement charges of $ 159 million related to lump sum pension settlement payments to terminated or retired individuals and completed its sale of the Northwest Operations. In accordance with ASC 715, Compensation - Retirement Benefits (ASC 715) , Frontier remeasured its pension plan during the year ended December 31, 2020. These remeasurements resulted in an increase in our pension liabilities and a remeasurement charge to Other comprehensive income (loss) of $ 506 million for the year ended December 31, 2020. For the pension plan, the largest contributors to the actuarial loss affecting the benefit obligation from December 31, 2019 to December 31, 2020 was the decrease in the discount rate from 3.40 % to 2.60 % and decrease in the interest rate related assumptions (cash balance interest crediting rates and lump sum conversion interest rates). For the pension plan, the largest contributors to the actuarial loss affecting the benefit obligation from December 31, 2018 to December 31, 2019 was the decrease in the discount rate from 4.30 % to 3.40 % and decrease in the interest rate related assumptions (cash balance interest crediting rates and lump sum conversion interest rates). We capitalized $ 25 million, $ 24 million and $ 26 million of pension and OPEB expense into the cost of our capital expenditures during the years ended December 31, 2020, 2019 and 2018, respectively, as the costs relate to our engineering and plant construction activities. The plan’s weighted average asset allocations at December 31, 2020 and 2019 by asset category are as follows: 2020 2019 Asset category: Equity securities 49 % 49 % Debt securities 37 % 39 % Alternative investments 14 % 12 % Total 100 % 100 % The plan’s expected benefit payments over the next 10 years are as follows: ($ in millions) Amount 2021 $ 255 2022 252 2023 253 2024 256 2025 257 2026-2030 1,239 Total $ 2,512 Prior to the CARES Act, required pension plan contributions for fiscal year 2020 were approximately $ 180 million. The CARES Act (passed in March 2020) allowed employers to postpone making pension contributions due in 2020 until January 4, 2021. As a result, Frontier decided to defer all of its remaining 2020 fiscal year required contributions (approximately $ 147 million including additional interest). On December 31, 2020, a $ 27 million contribution was made for the 2019 plan year. The remaining required contributions were further delayed past the January 4, 2021 deadline (approximately $ 120 million including additional interest to January 4, 2021). The consequence of this further delay is that contributions after the deadline of January 4, 2021 will require late penalty interest. However, Frontier has previously applied for a waiver of delayed contributions per minimum funding standard regulations under Section 412(c) of the Internal Revenue Code and Section 302(c) of the Employee Retirement Income Security Act of 1974. This waiver would delay payments by spreading the 2020 plan year contributions, determined as of January 1, 2020 (approximately $ 173 million in total), over the five subsequent plan years. In 2019, required pension plan contributions were approximately $ 166 million. In 2018, required pension plan contributions were approximately $ 150 million, consisting of cash payments of $ 113 million and the contribution of real property with a fair value of $ 37 million. See Note 9 for further discussion of contributed real estate. The accumulated benefit obligation for the plan was $ 3,640 million and $ 3,646 million at December 31, 2020 and 2019, respectively. Assumptions used in the computation of annual pension costs and valuation of the year-end obligations were as follows: 2020 2019 2018 Discount rate - used at year end to value obligation 2.60 % 3.40 % 4.30 % Discount rate - used at beginning of year to compute annual cost 3.40 % 4.30 % 3.70 % Expected long-term rate of return on plan assets 7.50 % 7.50 % 7.50 % Rate of increase in compensation levels 2.00 % 2.00 % 2.00 % Postretirement Benefits Other Than Pensions - “OPEB” The following tables set forth the OPEB plans’ benefit obligations, fair values of plan assets and the postretirement benefit liability recognized on our consolidated balance sheets as of December 31, 2020 and 2019 and the components of total postretirement benefit cost for the years ended December 31, 2020, 2019 and 2018. The below tables include all investment activity related to assets and obligations that are expected to be transferred in connection with the planned divestiture of our Northwest Operations: ( $ in millions) 2020 2019 Change in benefit obligation Benefit obligation at beginning of year $ 972 $ 965 Impact of Divestiture of Northwest Operations ( 31 ) - Service cost 20 20 Interest cost 33 41 Plan amendments - ( 149 ) Plan participants' contributions 9 7 Actuarial loss 100 129 Benefits paid ( 61 ) ( 47 ) Special termination benefits - 6 Benefit obligation at end of year $ 1,042 $ 972 Change in plan assets Fair value of plan assets at beginning of year $ - $ - Plan participants' contributions 9 7 Employer contribution 52 40 Benefits paid ( 61 ) ( 47 ) Fair value of plan assets at end of year $ - $ - Funded status $ ( 1,042 ) $ ( 972 ) Amounts recognized in the consolidated balance sheet Pension and other postretirement benefits - current $ ( 48 ) $ ( 43 ) Pension and other postretirement benefits - noncurrent $ ( 994 ) $ ( 900 ) Pension and other postretirement benefits - AHFS* $ - $ ( 29 ) Accumulated other comprehensive (gain) loss $ 74 $ ( 45 ) * Assets Held for Sale ( $ in millions ) 2020 2019 2018 Components of total postretirement benefit cost Service cost $ 20 $ 20 $ 21 Interest cost on projected benefit obligation 33 41 38 Amortization of prior service credit ( 32 ) ( 11 ) ( 9 ) Amortization of unrecognized (gain) loss 6 ( 4 ) 3 Net periodic postretirement benefit cost 27 46 53 OPEB special termination benefit enhancements - 6 - Gain on disposal, net ( 24 ) - - Total postretirement benefit cost $ 3 $ 52 $ 53 During 2020, actuarial losses of $ 100 million were primarily driven by reductions in the discount rates used to measure our OPEB plans. During 2019, Frontier amended the medical coverage for certain postretirement benefit plans, which resulted in a $ 149 million reduction in the accumulated postretirement benefit obligation. Remeasurement of the postretirement benefit plan obligation resulted in an actuarial loss of $ 129 million. Assumptions used in the computation of annual OPEB costs and valuation of the year-end OPEB obligations were as follows: 2020 2019 2018 Discount rate - used at year end to value obligation 2.60 % - 2.80 % 3.40 % - 3.50 % 4.30 % - 4.40 % Discount rate - used to compute annual cost 3.40 % - 3.50 % 4.30 % - 4.40 % 3.70 % - 3.80 % The OPEB plan’s expected benefit payments over the next 10 years are as follows: ($ in millions) Gross Benefit Medicare Part D Subsidy Total 2021 $ 49 $ - $ 49 2022 48 - 48 2023 48 - 48 2024 52 - 52 2025 48 - 48 2026-2030 278 2 280 Total $ 523 $ 2 $ 525 For purposes of measuring year-end benefit obligations, we used, depending on medical plan coverage for different retiree groups, a 7.00 % annual rate of increase in the per-capita cost of covered medical benefits, gradually decreasing to 5.00 % in the year 2029 and remaining at that level thereafter. The amounts in accumulated other comprehensive loss before tax that have not yet been recognized as components of net periodic benefit cost at December 31, 2020 and 2019 are as follows: Pension Plan OPEB ( $ in millions ) 2020 2019 2020 2019 Net actuarial loss $ 915 $ 899 $ 192 $ 105 Prior service credit - - ( 118 ) ( 150 ) Total $ 915 $ 899 $ 74 $ ( 45 ) The amounts recognized as a component of accumulated other comprehensive loss for the years ended December 31, 2020 and 2019 are as follows: Pension Plan OPEB ( $ in millions ) 2020 2019 2020 2019 Accumulated other comprehensive (gain) loss at beginning of year $ 899 $ 754 $ ( 45 ) $ ( 41 ) Net actuarial (gain) loss amortized during year ( 99 ) ( 58 ) ( 6 ) 4 Net loss on disposal recognized during the year ( 81 ) - ( 7 ) - Prior service credit amortized during year - - 32 11 Prior service credit occurring during year - - - ( 149 ) Net actuarial loss occurring during year 355 260 100 130 Settlement loss recognized ( 159 ) ( 57 ) - - Net amount recognized in comprehensive income (loss) for the year 16 145 119 ( 4 ) Accumulated other comprehensive (gain) loss at end of year $ 915 $ 899 $ 74 $ ( 45 ) 401(k) Savings Plans We sponsor employee retirement savings plans under section 401(k) of the Internal Revenue Code. The plans cover substantially all full-time employees. Under certain plans, we provide matching contributions. Employer contributions were $ 39 million, $ 44 million and $ 45 million for 2020, 2019 and 2018, respectively.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	12 Months Ended
Fair Value Of Financial Instruments	Dec. 31, 2020
Fair Value Of Financial Instruments [Abstract]
Fair Value Of Financial Instruments	(21) Fair Value of Financial Instruments : Fair value is defined under GAAP as the exit price associated with the sale of an asset or transfer of a liability in an orderly transaction between market participants at the measurement date. Valuation techniques used to measure fair value under GAAP must maximize the use of observable inputs and minimize the use of unobservable inputs. In addition, GAAP establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. The three input levels in the hierarchy of fair value measurements are defined by the FASB generally as follows: Input Level Description of Input Level 1 Observable inputs such as quoted prices in active markets for identical assets. Level 2 Inputs other than quoted prices in active markets that are either directly or indirectly observable. Level 3 Unobservable inputs in which little or no market data exists. The following tables represent Frontier’s pension plan assets measured at fair value on a recurring basis as of December 31, 2020 and 2019: Fair Value Measurements at December 31, 2020 ( $ in millions ) Total Level 1 Level 2 Level 3 Cash and Cash Equivalents $ 55 $ 55 $ - $ - U.S. Government Obligations 48 - 48 - Corporate and Other Obligations 506 - 506 - Common Stock 510 510 - - Preferred Stock 3 3 - - Interest in Registered Investment Companies (1) 140 140 - - Interest in Limited Partnerships and Limited Liability Companies 166 - - 166 Total investments at fair value $ 1,428 $ 708 $ 554 $ 166 Common/Collective Trusts (1) 1,073 Interest in Registered Investment Companies (1) 32 Interest and Dividend Receivable 5 Due from Broker for Securities Sold 22 Receivable Associated with Insurance Contract 7 Due to Broker for Securities Purchased ( 60 ) Total Plan Assets, at Fair Value $ 2,507 Fair Value Measurements at December 31, 2019 ( $ in millions ) Total Level 1 Level 2 Level 3 Cash and Cash Equivalents $ 46 $ 46 $ - $ - U.S. Government Obligations 39 - 39 - Corporate and Other Obligations 547 - 547 - Common Stock 552 552 - - Preferred Stock 4 4 - - Interest in Registered Investment Companies (1) 150 150 - - Interest in Limited Partnerships and Limited Liability Companies 163 - - 163 Total investments at fair value $ 1,501 $ 752 $ 586 $ 163 Common/Collective Trusts (1) 1,177 Interest in Registered Investment Companies (1) 87 Interest and Dividend Receivable 6 Due from Broker for Securities Sold 61 Receivable Associated with Insurance Contract 7 Due to Broker for Securities Purchased ( 109 ) Total Plan Assets, at Fair Value $ 2,730 (1) Investments that are measured at fair value using the net asset value (NAV) practical expedient have not been classified in the fair value hierarchy. The fair value of common/collective trusts are estimated using the NAV per share multiplied by the number of shares of the trust investment held as of the measurement date. Additionally, the fair value of certain assets totaling $ 32 million and $ 87 million, as of December 31, 2020 and 2019, respectively, included in “Interest in Registered Investment Companies” were estimated using the NAV practical expedient. These balances are intended to permit reconciliation of the fair value hierarchy to the plan asset amounts presented in Note 20 - Retirement Plans. There have been no reclassifications of investments between Levels 1, 2 or 3 assets during the years ended December 31, 2020 or 2019. The tables below set forth a summary of changes in the fair value of the Plan’s Level 3 assets for the years ended December 31, 2020 and 2019: Interest in Limited Partnerships and Limited Liability Companies ( $ in millions ) 2020 2019 Balance at beginning of year $ 163 $ 155 Realized gains 14 14 Unrealized gains 3 8 Sales and distributions ( 14 ) ( 14 ) Balance at end of year $ 166 $ 163 The following table provides further information regarding the redemption of the Plan’s Level 3 investments as well as information related to significant unobservable inputs and the range of values for those inputs for the Plan’s interest in certain limited partnerships and limited liability companies as of December 31, 2020: Liquidation Capitalization ( $ in millions ) Fair Value Period Rate Interest in Limited Partnerships and Limited Liability Companies (4) MS IFHF SVP LP Cayman (1) $ 1 4 years N/A RII World Timberfund, LLC (2) 5 2 years N/A 426 E. Casino Road, LLC (3) 17 N/A 7.00 % 100 Comm Drive, LLC (3) 10 N/A 7.75 % 100 CTE Drive, LLC (3) 11 N/A 9.50 % 6430 Oakbrook Parkway, LLC (3) 27 N/A 7.75 % 8001 West Jefferson, LLC (3) 29 N/A 8.75 % 1500 MacCorkle Ave SE, LLC (3) 15 N/A 8.75 % 400 S. Pike Road West, LLC (3) 1 N/A 8.50 % 601 N. US 131, LLC (3) 1 N/A 9.50 % 9260 E. Stockton Blvd., LLC (3) 7 N/A 7.25 % 120 E. Lime Street, LLC (3) 9 N/A 9.00 % 610 N. Morgan Street, LLC (3) 33 N/A 8.50 % Total Interest in Limited Partnerships and Limited Liability Companies $ 166 (1) The partnerships’ investment objective is to seek capital appreciation principally through investing in investment funds managed by third party investment managers who employ a variety of alternative investment strategies. These instruments are subject to certain withdrawal restrictions. The Plan is in the process of liquidating its interest in the partnerships and distributions are expected to be made over the next four years . (2) The fund’s objective is to realize substantial long-term capital appreciation by investing in timberland properties primarily in South America and Australia. This investment is subject to certain withdrawal restrictions. In 2019, the fund entered into liquidation period of the partnerships and distributions are expected to be made over the next two years . (3) The entity invests in commercial real estate properties that are leased to Frontier. The leases are triple net, whereby Frontier is responsible for all expenses, including but not limited to, insurance, repairs and maintenance and payment of property taxes. (4) All Level 3 investments have the same redemption frequency (through the liquidation of underlying investments) and redemption notice period (none). The fair value of these properties is based on independent appraisals. The following table summarizes the carrying amounts and estimated fair values for long-term debt at December 31, 2020 and 2019. For the other financial instruments including cash, accounts receivable, restricted cash, accounts payable and other current liabilities, the carrying amounts approximate fair value due to the relatively short maturities of those instruments. The fair value of our long-term debt (including $ 10,949 million of debt classified in Liabilities subject to compromise at December 31, 2020) is estimated based upon quoted market prices at the reporting date for those financial instruments. 2020 2019 Carrying Carrying ($ in millions) Amount Fair Value Amount Fair Value Total debt $ 16,769 $ 11,635 $ 17,516 $ 12,026 The fair value of our long-term debt is estimated based upon quoted market prices at the reporting date for those financial instruments.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
Commitments And Contingencies	Dec. 31, 2020
Commitments And Contingencies [Abstract]
Commitments And Contingencies	(22) Commitments and Contingencies : Although from time to time we make short-term purchasing commitments to vendors with respect to capital expenditures, we generally do not enter into firm, written contracts for such activities. In 2015, Frontier accepted the FCC’s CAF Phase II offer in 29 states, which provides $ 332 million in annual support through and in return, the Company is committed to make broadband available to approximately 774,000 locations within its footprint. This amount included approximately 41,000 locations and $ 19 million in annual support related to the four states of the Northwest Operations, which were disposed on May 1, 2020. On January 30, 2020, the FCC adopted an order establishing the Rural Digital Opportunity Fund (RDOF) program. The FCC held the RDOF Phase I auction from October 29, 2020 through November 25, 2020 and announced the results on December 7, 2020. Frontier was awarded approximately $ 371 million over ten years to build gigabit capable broadband over a fiber-to-the-premises network to approximately 127,000 locations across eight states (California, Connecticut, Florida, Illinois, New York, Pennsylvania, Texas, and West Virginia). Frontier submitted its Long Form application to the FCC on January 29, 2021 and, assuming the long-form application is granted by the FCC, anticipates that it will begin receiving funding on January 1, 2022, in which case, Frontier will be required to complete the buildout to these locations by December 31, 2027, with interim target milestones over this period. After the FCC updates its maps with more granular broadband availability information, the FCC plans to hold a second auction (RDOF Phase II) for any remaining locations with the remaining funding, up to approximately $ 11.2 billion. Recognizing that RDOF support will not be made available before the end of the sixth year of CAF Phase II support (i.e., December 31, 2020), the FCC’s RDOF order explains that CAF II recipients may elect to receive a seventh year of CAF Phase II support through December 31, 2021, whether or not they participate, or are successful in, an RDOF auction. Frontier timely elected to receive a seventh year of model-based support in 25 states. As such, Frontier will continue to receive annual CAF Phase II support in the remaining 25 states until December 31, 2021. Implementation of the RDOF could result in a material change in the level of funding that Frontier receives from the FCC under CAF II as early as 2022. On April 20, 2017, the FCC issued an Order that significantly altered how Commercial Data Services are regulated. Specifically, the Order adopted a test to determine, on a county-by-county basis, whether price cap ILECs, like Frontier’s DS1 and DS3 services, will continue to be regulated. The test resulted in deregulation in a substantial number of our markets and is allowing Frontier to offer its DS1 and DS3 services in a manner that better responds to the competitive marketplace and allows for commercial negotiation. The areas that remain regulated may be subject to price fluctuations depending upon the price cap formula that year. Multiple parties appealed the order in the 8th Circuit Court of Appeals. The Court of Appeals issued a ruling August 28, 2018, which upheld the vast majority of the FCC’s decision easing regulation of business data services of internet service providers and vacated and remanded one part of the order back to the FCC. On October 10, 2018, the FCC filed a Motion to Stay the Court’s Decision. On July 12, 2019, the FCC released an order addressing the matters remanded by the Court of Appeals. Frontier cannot predict the extent to which these regulatory changes could affect revenues at this time. On April 30, 2018, an amended consolidated class action complaint was filed in the United States District Court for the District of Connecticut on behalf of certain purported stockholders against Frontier, certain of its current and former directors and officers and the underwriters of certain Frontier securities offerings. The complaint was brought on behalf of all persons who (1) acquired Frontier common stock between February 6, 2015 and February 28, 2018, inclusive, and/or (2) acquired Frontier common stock or Mandatory Convertible Preferred Stock either in or traceable to Frontier’s offerings of common and preferred stock conducted on or about June 2, 2015 and June 8, 2015. The complaint asserted, among other things, violations of Section 10(b) of the Securities Exchange Act of 1934, as amended (the Exchange Act), and Rule 10b-5 thereunder, Section 20(a) of the Exchange Act and Sections 11 and 12 of the Securities Act of 1933, as amended (the Securities Act), in connection with certain disclosures relating to the CTF Acquisition. The complaint sought, among other things, damages and equitable and injunctive relief. On March 8, 2019, the District Court granted in its entirety Frontier’s motion to dismiss the complaint. The District Court dismissed with prejudice a number of claims and with respect to certain other claims that were not dismissed with prejudice, Plaintiffs were permitted to seek the court’s permission to refile. On May 10, 2019, Plaintiffs filed a motion for leave to amend along with a proposed amended complaint that is narrower in scope than the dismissed complaint. On March 24, 2020, the court denied plaintiffs’ motion for leave to amend, finding that they had not pled a viable claim. Plaintiffs appealed and the case was stayed by the Second Circuit Court of Appeals. We continue to dispute the allegations and intend to vigorously defend against such claims. In addition, shareholders have filed derivative complaints on behalf of the Company in Connecticut, California, and Delaware courts. The derivative complaints are based, generally, on the same facts asserted in the consolidated class action complaint and allege against current and former officers and directors of the Company (i) breach of fiduciary duty claims for disseminating false and misleading information to shareholders, failure to manage internal controls, and failure to oversee and manage the company; (ii) unjust enrichment and waste of corporate assets claims; and (iii) violations of Section 14(a) of the Exchange Act for the false and misleading statements. We also dispute the allegations in the derivative complaints described above and intend to vigorously defend against such claims. Given that all of these matters are in the early stages of litigation, we are unable to estimate a reasonably possible range of loss, if any, that may result. In addition, we are party to various legal proceedings (including individual actions, class and putative class actions, and governmental investigations) arising in the normal course of our business covering a wide range of matters and types of claims including, but not limited to, general contract disputes, billing disputes, rights of access, taxes and surcharges, consumer protection, advertising, sales and the provision of services, trademark and patent infringement, employment, regulatory, tort, claims of competitors and disputes with other carriers. Litigation is subject to uncertainty and the outcome of individual matters is not predictable. However, we believe that the ultimate resolution of all such matters, after considering insurance coverage or other indemnities to which we are entitled, will not have a material adverse effect on our financial position, results of operations, or cash flows. In October 2013, the California Attorney General’s Office notified certain Verizon companies, including one of the subsidiaries that we acquired in the CTF Acquisition, of potential violations of California state hazardous waste statutes primarily arising from the disposal of electronic components, batteries and aerosol cans at certain California facilities. We are cooperating with this investigation. We have accrued an amount for potential penalties that we deem to be probable and reasonably estimated, and we do not expect that any potential penalties, if ultimately incurred, will be material in comparison to the established accrual. We accrue an expense for pending litigation when we determine that an unfavorable outcome is probable, and the amount of the loss can be reasonably estimated. Legal defense costs are expensed as incurred. None of our existing accruals for pending matters, after considering insurance coverage, is material. We monitor our pending litigation for the purpose of adjusting our accruals and revising our disclosures accordingly, when required. Litigation is, however, subject to uncertainty, and the outcome of any particular matter is not predictable. We will vigorously defend our interests in pending litigation, and as of this date, we believe that the ultimate resolution of all such matters, after considering insurance coverage or other indemnities to which we are entitled, will not have a material adverse effect on our consolidated financial position, results of operations, or our cash flows. As part of the sale of the Northwest Operations, Frontier indemnified the purchaser for customary post-closing matters, including, among other things, breaches of certain covenants, agreements and warranties, and other obligations included in the purchase agreement. While Frontier intends to comply with its obligations under the purchase agreement, we could be obligated to make payments pursuant to these provisions in the future. We conduct certain of our operations in leased premises and also lease certain equipment and other assets pursuant to operating leases. The lease arrangements have terms ranging from 1 to 99 years and several contain rent escalation clauses providing for increases in monthly rent at specific intervals. When rent escalation clauses exist, we record annual rental expense based on the total expected rent payments on a straight-line basis over the lease term. Certain leases also have renewal options. Renewal options that are reasonably assured are included in determining the lease term. Effect of Automatic Stay Subject to certain exceptions under the Bankruptcy Code, the filing of the Company Parties’ Chapter 11 Cases automatically stayed the continuation of most legal proceedings or the filing of other actions against or on behalf of the Company Parties or their property to recover on, collect or secure a claim arising prior to the Petition Date or to exercise control over property of the Company Parties’ bankruptcy estates, unless and until the Bankruptcy Court modifies or lifts the automatic stay as to any such claim. Notwithstanding the general application of the automatic stay described above, governmental authorities may determine to continue actions brought under their police and regulatory powers. We are party to contracts with several unrelated long-distance carriers. The contracts provide fees based on traffic they carry for us subject to minimum monthly fees. At December 31, 2020, the estimated future payments for obligations under our noncancelable long-distance contracts and joint pole and communications service agreements are as follows: ($ in millions) Amount Year ending December 31: 2021 $ 85 2022 22 2023 19 2024 4 2025 2 Thereafter 4 Total $ 136 At December 31, 2020, we have outstanding performance letters of credit as follows: ($ in millions) Amount CNA Financial Corporation (CNA) $ 49 AIG Insurance 28 Zurich (1) 62 Total $ 139 (1) Zurich letters of credit exclude approximately $57 million of cash held in trust in lieu of issuing letters of credit. CNA serves as our insurance carrier with respect to casualty claims (auto liability, general liability and workers’ compensation) with dates of loss prior to June 1, 2017 (except for those claims which arise out of the operations acquired from CTF that have dates of loss prior to April 1, 2016). As our insurance carrier, they administer the casualty claims and make claim payments on our behalf. We reimburse CNA for such services upon presentation of their invoice. To serve as our carrier and make payments on our behalf, CNA requires that we establish a letter of credit in their favor. CNA could potentially draw against this letter of credit if we failed to reimburse CNA in accordance with the terms of our agreement. The amount of the letter of credit is reviewed annually and adjusted based on claims history. Zurich serves as our insurance carrier with respect to casualty claims (auto liability, general liability and workers’ compensation) with dates of loss from June 1, 2017 and going forward. As our insurance carrier, they administer the casualty claims and make claim payments on our behalf. We reimburse Zurich for such services upon presentation of their invoice. To serve as our carrier and make payments on our behalf, Zurich requires that we establish letters of credit in their favor. Zurich could potentially draw against these letters of credit if we failed to reimburse Zurich in accordance with the terms of our agreement. The amount of the letters of credit is reviewed annually and adjusted based on claims history. AIG Insurance serves as our insurance carrier with respect to casualty claims (auto liability, general liability and workers’ compensation) that were acquired from CTF, as well as new claims which arise out of the operations acquired from CTF that have dates of loss prior to April 1, 2016. Sedgwick, a third-party claims administrator, administers the casualty claims and makes claim payments on our behalf. We reimburse Sedgwick for such services upon presentation of their invoice. However, to serve as our insurance carrier, AIG Insurance requires that we establish a letter of credit in their favor. AIG Insurance could potentially draw against this letter of credit if we failed to meet the insurance-related and claims-related obligations we assumed in accordance with the terms of our agreement. The amount of the letter of credit is reviewed annually and adjusted based on claims history.

Description Of Business And S_2

Description Of Business And Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2020
Description Of Business And Summary Of Significant Accounting Policies [Abstract]
Description Of Business	(a) Description of Business : Frontier Communications Corporation (Frontier) is a provider of communications services in the United States, with approximately 3.6 million customers, 3.1 million broadband subscribers and 16,200 employees, operating in 25 states. Frontier was incorporated in 1935, originally under the name of Citizens Utilities Company and was known as Citizens Communications Company until July 31, 2008. Frontier and its subsidiaries are referred to as “we,” “us,” “our,” “Frontier,” or the “Company” in this report.
Basis Of Presentation And Use Of Estimates	(b) Basis of Presentation and Use of Estimates : Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Certain reclassifications of amounts previously reported have been made to conform to the current presentation. All significant intercompany balances and transactions have been eliminated in consolidation. For our financial statements as of and for the period ended December 31 , 2020, we evaluated subsequent events and transactions for potential recognition or disclosure through the date that we filed this Form 10-K with the Securities and Exchange Commission (SEC). The preparation of our financial statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities at the date of the financial statements, (ii) the disclosure of contingent assets and liabilities, and (iii) the reported amounts of revenue and expenses during the reporting period. Actual results may differ from those estimates. Estimates and judgments are used when accounting for the allowance for doubtful accounts, asset impairments, indefinite-lived intangibles, depreciation and amortization, income taxes, business combinations, and pension and other postretirement benefits, among others.
Going Concern	(c) Going Concern : In connection with the preparation of our consolidated financial statements, we conducted an evaluation as to whether there were conditions and events, considered in the aggregate, which raised substantial doubt as to the entity’s ability to continue as a going concern within one year after the date of the issuance of our consolidated financial statements. Our consolidated financial statements have been prepared assuming that we will continue as a going concern, which contemplates continuity of operations, realization of assets, and satisfaction of liabilities in the normal course of business. On April 14, 2020 (the Petition Date), Frontier Communications Corporation and its subsidiaries (collectively, the Company Parties or the Debtors and, as they may be reorganized pursuant to the Plan, the Reorganized Company Parties or the Reorganized Debtors) commenced cases under chapter 11 (the Chapter 11 Cases) of title 11 of the United States Code (the Bankruptcy Code) in the U.S. Bankruptcy Court for the Southern District of New York (the Bankruptcy Court). On May 15, 2020, the Company Parties filed a proposed Joint Plan of Reorganization and related Disclosure Statement, each of which were amended on June 26, 2020, June 29, 2020 and June 30, 2020. On May 15, 2020, the Debtors also filed a proposed order approving the Disclosure Statement and various plan solicitation materials, including the solicitation and voting procedures, which was revised on June 29, 2020 (including modifications to some of the exhibits). On June 30, 2020, the Bankruptcy Court entered the modified order approving the adequacy of the Disclosure Statement and the solicitation and notice procedures and the forms of voting ballots and notices in connection therewith. The order established June 29, 2020 as the voting record date, July 2, 2020 as the solicitation launch date and July 31, 2020 as the voting deadline. On August 21, 2020, the Company Parties filed the Fifth Amended Joint Plan of Reorganization of Frontier Communications Corporation and Its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code (the Plan) with the Bankruptcy Court. On August 27, 2020, the Bankruptcy Court entered the Order Confirming the Fifth Amended Joint Plan of Reorganization of Frontier Communications Corporation and its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code (the Confirmation Order), which approved and confirmed the Plan. The effective date of the Plan will occur once all conditions precedent to the Plan have been satisfied (the Effective Date). Our ability to continue as a going concern is contingent upon, among other things, our ability to, subject to the Bankruptcy Court’s approval, implement the Plan, successfully emerge from the Chapter 11 Cases and generate sufficient liquidity from the Restructuring to meet our obligations and operating needs. As a result of risks and uncertainties related to (i) the Company’s ability to successfully consummate the Plan and emerge from the Chapter 11 Cases, and (ii) the effects of disruption from the Chapter 11 Cases making it more difficult to maintain business, financing and operational relationships, together with the Company’s recurring losses from operations and accumulated deficit, substantial doubt exists regarding our ability to continue as a going concern. For detailed discussion about the Chapter 11 Cases and the Plan, refer to Note 3. Our consolidated financial statements do not include any adjustments related to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might be necessary should we be unable to continue as a going concern. The filing of the Chapter 11 Cases constituted an event of default that accelerated substantially all of our obligations under the JPM Credit Agreement (as defined herein), the Company’s 8.000 % first lien secured notes due April 1, 2027 (the Original First Lien Notes), the Company’s 8.500 % second lien secured notes due April 1, 2026 (the Original Second Lien Notes), our unsecured notes and debentures and the secured and unsecured debentures of our subsidiaries. As of December 31, 2020, amounts that were outstanding under the JPM Credit Agreement, our Original First Lien Notes, and our Original Second Lien Notes have been repaid in full. We have reclassified our unsecured notes and debentures and the secured and unsecured debentures of our subsidiaries to “Long term debt due within one year” or “Liabilities Subject to Compromise”, based on the event of default or reinstatement provisions of each security in the Restructuring Support Agreement, on our consolidated balance sheet as of December 31, 2020. For additional discussion related to our debt obligations, and details of our refinancing of our secured debt, refer to Note 9.
Impact Of Covid-19	(d) Impact of COVID-19: On March 11, 2020, the World Health Organization declared the highly contagious and lethal corona virus outbreak a global pandemic (COVID-19) and recommended containment and other mitigation measures worldwide to lessen the transmission of COVID-19. In the first half of 2020, governments from around the world, including the United States federal government as well as state and local governments reacted to this public health crisis, imposing travel restrictions and restrictions on large gatherings of people, which includes school and non-essential business closures. The rapid spread of COVID-19 and the drastic responses being taken to curb its spread have resulted in a significant negative impact to the global and domestic economies, which will increase the longer these limitations are in place. In an effort to reduce the economic impacts of COVID-19, the United States federal government has responded with multiple stimulus bills, including the Coronavirus Aid, Relief, and Economic Security (CARES) Act, the largest economic stimulus legislation in American history. Despite these efforts, the short-term and long-term impacts of COVID-19 cannot be determined. With more people staying at home and an increased reliance on broadband and telephone networks, the Federal Communications Commission (FCC) issued the Keep Americans Connected Pledge on March 11, 2020, which provided for telecommunication providers, including Frontier, to not terminate service and to waive any late payment fees through June 30, 2020 for certain customers due to economic circumstances they are facing related to COVID-19 as well as making WIFI hotspots available to all Americans who need them. In addition, some of the states we operate in have issued executive orders as a result of COVID-19 that further impact our business, including prohibiting the disconnection of services for customers for the length of the state of emergency. While the initial 60-day period of the Keep Americans Connected Pledge has expired, state and federal governments continue to ask companies to aid in pandemic response. While certain customers have taken advantage of our COVID-19 related relief programs, as of December 31, 2020, very few had past due balances beyond the point of normal disconnection. In addition to committing to the Keep Americans Connected Pledge, Frontier’s response to COVID-19 has included several operational safety precautions such as limiting our product offerings in certain markets for certain periods, including not allowing our field service employees to enter a customer’s home for a period of time, a limitation which is no longer in effect. We are continuing to require personal protective equipment on any employees entering a customer location. The percentage of Frontier’s employees who have reported testing positive for COVID-19 is small and continues to track below the percentage of reported cases both nationally and in those states in which Frontier has a significant number of employees. Through December 31, 2020, we had not experienced any significant disruptions in our supply chain; however, some of our business partners, particularly those vendors operating outside of the United States, have been more greatly impacted which has affected our service levels and distribution of work. As the COVID-19 pandemic continues, certain states are currently considering legislation or other regulations to adopt additional protections for workers impacted by COVID-19. To date, we have not experienced significant disruptions in our workforce due to COVID-19 related absences or legislative or regulatory changes. Given the unprecedented and evolving nature of the pandemic and the swift moving response of multiple levels of government as well as the uncertainty of funding available for services provided, the full impact of these changes and potential changes on the Company are unknown at this time. While overall the operational and financial impacts to Frontier of the COVID-19 pandemic for the year ended December 31, 2020 were not significant, we continue to closely monitor the ongoing impact to our employees, our customers, our business and our results of operations. We have experienced a slowdown in service activations and an increase in deactivations for our SMB customers; to date, these negative impacts have been partially offset by higher residential activations and lower churn. We also continue to closely track our customers’ payment activity as well as external factors, including the expiration of federal wage subsidies for individuals and small businesses which could materially impact payment trends. With more people working from home, we have experienced higher demands on our network and higher sales activity for our residential broadband service offering. This sustained increase in network demand could lead to reduced network availability and potential outages, which may impair our ability to meet customer service level commitments, lead to higher costs, higher customer churn and potential increased regulatory actions. These potential changes, among others, could have a material financial impact to Frontier.
Debtor-In-Possession	(e) Debtor-In-Possession: In general, as debtors-in-possession under the Bankruptcy Code, we are authorized to continue to operate as an ongoing business but may not engage in transactions outside the ordinary course of business without the prior approval of the Bankruptcy Court. Pursuant to certain motions and applications intended to limit the disruption of the bankruptcy proceedings on our operations (the First Day Motions) and other motions filed with the Bankruptcy Court, the Bankruptcy Court has authorized us to conduct our business activities in the ordinary course, including, among other things and subject to the terms and conditions of such orders, authorizing us to obtain DIP financing, pay employee wages and benefits, settle certain de minimis disputes and pay vendors and suppliers in the ordinary course for all goods and services.
Cash Equivalents	(f) Cash Equivalents: We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents. Restricted cash of $ 58 million and $ 50 million is included within “other assets” on our consolidated balance sheet as of December 31, 2020 and 2019, respectively. These amounts represent Letters of Credit Obligations and utility adequate assurance account that is required under bankruptcy rules .
Revenue Recognition	(g) Revenue Recognition : Revenue for data & Internet services, voice services, video services and switched and non-switched access services is recognized as the individual performances obligations to the customer are satisfied. Services that are billed in advance include monthly recurring network access services (including data services), special access services, and monthly recurring voice, video, and related charges. Revenue is recognized as services are provided by measuring progress toward the complete satisfaction of the Company’s performance obligations. Progress is measured monthly based on months completed as a portion of the total contract. The unearned portion of these fees is initially deferred as a component of “Advanced billings” on our consolidated balance sheet and recognized as revenue over the period that the services are provided. Services that are billed in arrears include non-recurring network access services (including data services), switched access services, and non-recurring voice and video services. The earned but unbilled portion of these fees is recognized as revenue in our consolidated statements of operations and accrued in “Accounts receivable” on our consolidated balance sheet in the period that services are provided. Excise taxes are recognized as a liability when billed. Satisfaction of Performance Obligations Frontier satisfies its obligations to customers by transferring goods and services in exchange for consideration received from the customer. The timing of Frontier’s satisfaction of the performance obligation often differs from the timing of the customer’s payment, which results in the recognition of a contract asset or a contract liability. Frontier recognizes a contract asset or liability when the Company transfers goods or services to a customer and bills an amount which differs from the revenue allocated to the related performance obligations. Bundled Service and Allocation of Discounts When customers purchase more than one service, the revenue allocable to each service is determined based upon the relative stand-alone selling price of each service received. We frequently offer service discounts as an incentive to customers. Service discounts reduce the total transaction price allocated to the performance obligations that are satisfied over the term of the customer contract. We may also offer incentives which are considered cash equivalents (e.g. Visa gift cards) that similarly result in a reduction of the total transaction price as well as lower revenue over the term of the contract. A contract asset is often created during the beginning of the contract term when the term of the incentive is shorter than the contract term. These contract assets are realized over the term of the contract as our performance obligations are satisfied and customer consideration is received. Customer Incentives In the process of acquiring and/or retaining customers, we may issue a variety of other incentives aside from service discounts or cash equivalent incentives. Those incentives that have stand-alone value (e.g. gift cards not considered cash equivalents or free goods/services) are considered a separate performance obligation. As a result, while these incentives are free to the customer, a portion of the consideration received from the customer over the contract term is ascribed to them based upon their relative stand-alone selling price. The revenue, reflected in “Other” revenue, and costs, reflected in “Network access expenses”, for these incentives are recognized when they are delivered to the customer and the performance obligation is satisfied. Similar to discounts, these types of incentives generally result in the creation of a contract asset during the beginning of the contract term which is recorded in Other current assets and Other assets on our consolidated balance sheet. Upfront Fees All non-refundable upfront fees provide our customers with a material right to renew, and therefore, are deferred and amortized into revenue over the expected period for which related services are provided. With upfront fees assessed at the beginning of a contract, a contract liability is often created, which is reduced over the term of the contract as the performance obligations are satisfied. The contract liabilities are recorded in Other current liabilities and Other liabilities on our consolidated balance sheet. Contributions in Aid of Construction (CIAC) It is customary for us to charge customers for certain construction activities. These activities are requested by the customer and construction charges are assessed at the beginning of a contract. When charges are incurred, a contract liability is often created, which is reduced over the term of the contract as performance obligations are satisfied. The contract liabilities are recorded in Other current liabilities and Other liabilities on our consolidated balance sheet. Contract Acquisition Costs Certain costs to acquire customers are deferred and amortized over the expected customer life (average of 4.0 years). For Frontier, this includes certain commissions paid to acquire new customers. Commissions attributable to new customer contracts are deferred and amortized into expense. Unamortized deferred commissions are recorded in Contract acquisition costs and Other assets on our consolidated balance sheet. Surcharges and Subsidies Frontier collects various taxes from its customers and subsequently remits these taxes to governmental authorities. Substantially all of these taxes are recorded through the consolidated balance sheet and presented on a net basis in our consolidated statements of operations. We also collect Universal Service Fund (USF) surcharges from customers (primarily federal USF), of $ 193 million, $ 221 million, and $ 213 million for the years ended December 31, 2020, 2019 and 2018, respectively, and video franchise fees of $ 30 million, $ 40 million, and $ 47 million for the years ended December 31, 2020, 2019, and 2018, respectively, that we have recorded on a gross basis in our consolidated statements of operations and included within “Revenue” and “Network related expenses. We accepted the FCC’s Connect America Fund (CAF) Phase II and RDOF offers of support, which are intended to provide long-term support for broadband in high cost unserved or underserved areas. We are recognizing these FCC subsidies into revenue on a straight-line basis over the seven year funding term for CAF Phase II and the ten year funding term for RDOF.
Property, Plant And Equipment	(h) Property, Plant and Equipment : Property, plant and equipment are stated at original cost, including capitalized interest, or fair market value as of the date of acquisition for acquired properties. Maintenance and repairs are charged to operating expenses as incurred. The gross book value of routine property, plant and equipment retirements is charged against accumulated depreciation
Definite And Indefinite Lived Intangible Assets	(i) Definite and Indefinite Lived Intangible Assets: Intangible assets arising from business combinations, such as customer lists, royalty agreements, and tradenames, are initially recorded at estimated fair value . Frontier amortizes its customer list and certain other finite-lived intangible assets over their estimated useful lives on the accelerated method of sum of the years’ digits and its royalty agreement over its estimated useful life on the straight-line method. Definite lived and Indefinite lived intangible assets are assessed for impairment annually, as of December 31, or more frequently, if events or changes in circumstances indicate the estimated fair value may be less than the carrying amount. Additionally, Frontier reviews whether factors exist that would necessitate a change in useful life and a different amortization period.
Impairment Of Long-Lived Assets And Long-Lived Assets To Be Disposed Of	(j) Impairment of Long-Lived Assets and Long-Lived Assets to Be Disposed Of : We review long-lived assets to be held and used, including customer lists and property, plant and equipment, and long-lived assets to be disposed of for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by comparing the carrying amount of the asset to the future undiscounted net cash flows expected to be generated by the asset. Recoverability of assets held for sale is measured by comparing the carrying amount of the assets to their estimated fair market value. If any assets are considered to be impaired, the impairment is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value. Also, we periodically reassess the useful lives of our long-lived assets to determine whether any changes are required.
Lease Accounting	(k) Lease Accounting: We determine if an arrangement contains a lease at inception. Right-of-use (ROU) assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating and Finance lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating and finance lease ROU asset also includes any lease payments made and excludes lease incentives. Our lease terms used in accounting for leases may reflect options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for operating leases is recognized on a straight-line basis over the lease term. ROU assets for operating leases are recorded to “Other Assets”, and the related liabilities recorded to “Other current liabilities”, and “Other liabilities” on our consolidated balance sheets. Assets subject to finance leases are included in “Property, Plant & Equipment”, with corresponding liabilities recorded to “Other current liabilities”, and “Other liabilities” on our consolidated balance sheets.
Income Taxes And Deferred Income Taxes	(l) Income Taxes and Deferred Income Taxes : We file a consolidated federal income tax return. We utilize the asset and liability method of accounting for income taxes. Under the asset and liability method, deferred income taxes are recorded for the tax effect of temporary differences between the financial statement basis and the tax basis of assets and liabilities using tax rates expected to be in effect when the temporary differences are expected to reverse. We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If we determine that we are not able to realize a portion of our net deferred tax assets in the future, we would make an adjustment to the deferred tax asset valuation allowance, which would increase the provision for income taxes. The tax effect of a change in tax law or rates included in income tax expense from continuing operations includes effect of changes in deferred tax assets and liabilities initially recognized through a charge or credit to other comprehensive income (loss). The residual tax effects typically are released when the item giving rise to the tax effect is disposed of, liquidated, or terminated. Since the Company has adopted the portfolio approach to release the residual tax effects, there is no release for the residual tax effect from the sale of our Northwest Operations.
Stock Plans	(m) Stock Plans : We have various stock-based compensation plans. Awards under these plans are granted to eligible employees and directors. Awards may be made in the form of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units or other stock-based awards, including awards with performance, market and time-vesting conditions. Our general policy is to issue shares from treasury upon the grant of restricted shares, earning of performance shares and the exercise of options. The compensation cost recognized is based on awards ultimately expected to vest. GAAP requires forfeitures to be estimated and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
Net Loss Per Share Attributable To Frontier Common Shareholders	(n) Net Loss Per Share Attributable to Frontier Common Shareholders : Basic net loss per common share is computed using the weighted average number of common shares outstanding during the period being reported on, excluding unvested restricted stock awards. The impact of dividends paid on unvested restricted stock awards have been deducted in the determination of basic and diluted net income (loss) per share attributable to Frontier common shareholders. Except when the effect would be antidilutive, diluted net income per common share reflects the dilutive effect of certain common stock equivalents, as described further in Note 16 – Net Loss Per Common Share.
Assets Held For Sale	(o) Assets Held for Sale: We classify assets and related liabilities as held for sale when the following criteria are met: when management has committed to a plan to sell the asset, the asset is available for immediate sale, there is an active program to locate a buyer and the sale and transfer of the asset is probable within one year. Assets and liabilities are presented separately on the Consolidated Balance Sheets with a valuation allowance, if necessary, to recognize the net carrying amount at the lower of cost or fair value, less costs to sell. Depreciation and amortization for property, plant and equipment and finite-lived intangible assets, are not recorded while these assets are classified as held for sale. Assets held for sale are tested for recoverability each period that they are classified as held for sale. On May 1, 2020, Frontier completed the sale of its operations and associated assets in Washington, Oregon, Idaho, and Montana (Northwest Operations or Northwest Ops). As of December 31, 2019, the assets and liabilities of the Northwest Operations were classified as held for sale on our consolidated balance sheets, and the amounts and information of the Company in the footnotes as they are presented do not include assets and liabilities that have been reclassified, refer to Note 8.

Chapter 11 Filing And Other R_2

Chapter 11 Filing And Other Related Matters (Tables)	12 Months Ended
Chapter 11 Filing And Other Related Matters (Tables)	Dec. 31, 2020
Chapter 11 Filing And Other Related Matters [Abstract]
Schedule Of Liabilities Subject To Compromise	As of ($ in millions) December 31, 2020 Accounts payable $ 57 Other current liabilities 62 Accounts payable, and other current liabilities 119 Debt subject to compromise 10,949 Accrued interest on debt subject to compromise 497 Long-term debt and accrued interest 11,446 Liabilities subject to compromise $ 11,565
Schedule Of Reorganization Items	For the year ended ($ in millions) December 31, 2020 Write-off of debt issuance costs and original issue net discount on debt subject to compromise $ 93 Debtor-in-possession financing costs 121 Secured Creditor Settlement 58 Professional fees and other bankruptcy related costs 137 Reorganization items, net $ 409

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
Revenue Recognition (Tables)	Dec. 31, 2020
Revenue Recognition [Abstract]
Disaggregation Of Revenue	For the year ended December 31, ($ in millions) 2020 2019 2018 Data and Internet services $ 3,478 $ 3,756 $ 3,878 Voice services 2,085 2,500 2,721 Video services 789 1,005 1,085 Other 429 477 544 Revenue from contracts with customers (1) 6,781 7,738 8,228 Subsidy and other regulatory revenue (2) 374 369 383 Total revenue $ 7,155 $ 8,107 $ 8,611 For the year ended December 31, ($ in millions) 2020 2019 2018 Consumer $ 3,586 $ 4,153 $ 4,380 Commercial 3,195 3,585 3,848 Revenue from contracts with customers (1) 6,781 7,738 8,228 Subsidy and other regulatory revenue (2) 374 369 383 Total revenue $ 7,155 $ 8,107 $ 8,611 (1) Includes $ 67 million, $ 70 million, and $ 73 million of lease revenue for the years ended December 31, 2020, 2019, and 2018 respectively. (2) Includes $ 30 million in transition services provided to the purchaser in connection with the divestiture of the Northwest Operations for the year ended December 31, 2020.
Summary Of Changes In Assets	Contract Acquisition Costs ($ in millions) Current Noncurrent Balance at January 1, 2019 $ 107 $ 127 Commissions deferred 138 6 Commission costs recognized ( 131 ) - Reclass to assets held for sale ( 9 ) ( 12 ) Balance at December 31, 2019 105 121 Commissions deferred 94 13 Commission costs recognized ( 116 ) ( 4 ) Reclassified between Current and Noncurrent 14 ( 14 ) Balance at December 31, 2020 $ 97 $ 116
Changes In Contract Assets And Contract Liabilities	Contract Assets Contract Liabilities ($ in millions) Current Noncurrent Current Noncurrent Balance at January 1, 2020 $ 37 $ 8 $ 41 $ 21 Revenue recognized included in opening contract balance ( 34 ) - ( 68 ) ( 12 ) Cash received, excluding amounts recognized as revenue - - 85 11 Credits granted, excluding amounts recognized as revenue 3 1 - - Reclassified between Current and Noncurrent - - - - Balance at December 31, 2020 $ 6 $ 9 $ 58 $ 20 Contract Assets Contract Liabilities ($ in millions) Current Noncurrent Current Noncurrent Balance at January 1, 2019 $ 44 $ 25 $ 49 $ 22 Revenue recognized included in opening contract balance ( 39 ) ( 12 ) ( 81 ) ( 17 ) Cash received, excluding amounts recognized as revenue - - 78 16 Credits granted, excluding amounts recognized as revenue 30 1 - - Reclassified between Current and Noncurrent 5 ( 5 ) - - Reclassified to held for sale ( 3 ) ( 1 ) ( 5 ) - Balance at December 31, 2019 $ 37 $ 8 $ 41 $ 21
Performance Obligations, Revenue	Revenue from remaining ($ in millions) performance obligations 2021 $ 1,426 2022 651 2023 288 2024 118 2025 69 Thereafter 139 Total $ 2,691

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
Accounts Receivable (Tables)	Dec. 31, 2020
Accounts Receivable [Abstract]
Accounts Receivable	($ in millions) 2020 2019 Retail and Wholesale $ 608 $ 678 Other 75 71 Less: Allowance for doubtful accounts ( 130 ) ( 120 ) Accounts receivable, net $ 553 $ 629
Schedule Of Allowance For Doubtful Accounts	Decreases: Reclassified Balance at ASC 606 Increases: Write-offs to Balance at beginning of Transition Charged to and Customer Assets Held end of ( $ in millions ) the Period Adjustment Revenue Credits for Sale the Period 2018 $ 69 $ 32 $ 93 $ ( 89 ) $ - $ 105 2019 $ 105 $ - $ 109 $ ( 83 ) $ ( 11 ) $ 120 2020 $ 120 $ - $ 106 $ ( 96 ) $ - $ 130

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
Property, Plant And Equipment (Tables)	Dec. 31, 2020
Property, Plant And Equipment [Abstract]
Property, Plant And Equipment, Net	Estimated ($ in millions) Useful Lives 2020 2019 Land N/A $ 212 $ 217 Buildings and leasehold improvements 40 years 2,139 2,171 General support 5 to 15 years 1,643 1,624 Central office/electronic circuit equipment 5 to 8 years 8,270 7,968 Poles 30 years 1,371 1,274 Cable, fiber and wire 15 to 25 years 11,883 11,312 Conduit 50 years 1,619 1,608 Construction work in progress 558 378 Property, plant and equipment 27,695 26,552 Less: Accumulated depreciation ( 14,764 ) ( 13,589 ) Property, plant and equipment, net $ 12,931 $ 12,963
Schedule Of Depreciation Expense	For the year ended December 31, ($ in millions) 2020 2019 2018 Depreciation expense $ 1,255 $ 1,335 $ 1,385

Goodwill And Other Intangibles

Goodwill And Other Intangibles (Tables)	12 Months Ended
Goodwill And Other Intangibles (Tables)	Dec. 31, 2020
Goodwill And Other Intangibles [Abstract]
Components Of Other Intangibles	2020 2019 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying ($ in millions) Amount Amortization Amount Amount Amortization Amount Other Intangibles: Customer base $ 4,332 $ ( 3,781 ) $ 551 $ 4,332 $ ( 3,452 ) $ 880 Trade name 122 - 122 122 - 122 Royalty agreement 72 ( 68 ) 4 72 ( 54 ) 18 Total other intangibles $ 4,526 $ ( 3,849 ) $ 677 $ 4,526 $ ( 3,506 ) $ 1,020
Schedule Of Amortization Expense	For the year ended December 31, ($ in millions) 2020 2019 2018 Amortization expense $ 343 $ 445 $ 569

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
Long-Term Debt (Tables)	Dec. 31, 2020
Long-Term Debt [Abstract]
Long-Term Debt	For the year ended December 31, 2020 ($ in millions) January 1, 2020 Payments and Retirements New Borrowings December 31, 2020 Interest Rate at December 31, 2020* Secured debt issued by Frontier $ 5,711 $ ( 5,697 ) $ 4,950 $ 4,964 5.747 % Unsecured debt issued by Frontier 10,949 - - 10,949 9.193 % Secured debt issued by subsidiaries 106 - - 106 8.368 % Unsecured debt issued by subsidiaries 750 - - 750 6.897 % Debt prior to reclassification to liabilities subject to compromise $ 17,516 $ ( 5,697 ) $ 4,950 $ 16,769 8.065 % Less: Debt Issuance Costs ( 168 ) - Less: Debt Premium/(Discount) ( 46 ) ( 39 ) Debt, less unamortized debt issuance costs and discounts 17,302 16,730 Less: Current Portion ( 994 ) ( 5,781 ) Less: Debt subject to compromise - ( 10,949 ) Total Long-term debt $ 16,308 $ - * Interest rate includes amortization of debt issuance costs and debt premiums or discounts. The interest rates at December 31, 2020 represent a weighted average of multiple issuances. Since the filing of Chapter 11 Bankruptcy, Frontier has not made any payments related to accrued interest for any debt obligations that are subject to compromise.
Schedule Of Unsecured Debt	December 31, 2020 December 31, 2019 Principal Interest Principal Interest ($ in millions) Outstanding Rate Outstanding Rate Secured debt issued by Frontier Revolver due 2/27/2024 (1) $ - $ 749 4.760 % (Variable) Term loan due 6/15/2024 (2) - 1,699 5.550 % (Variable) First lien notes due 4/1/2027 - 1,650 8.000 % Second lien notes due 4/1/2026 - 1,600 8.500 % DIP-to-Exit Revolving Facility - - DIP-to-Exit term loan due 10/8/2027 1,250 5.750 % (Variable) - DIP-to-Exit First lien notes due 10/15/2027 1,150 5.875 % - DIP-to-Exit First lien notes due 5/1/2028 1,550 5.000 % - DIP-to-Exit Second lien notes due 5/1/2029 1,000 6.750 % - IDRB due 5/1/2030 14 6.200 % 13 6.200 % Total secured debt issued by Frontier 4,964 5,711 Unsecured debt issued by Frontier Senior notes due 4/15/2020 172 8.500 % 172 8.500 % Senior notes due 9/15/2020 55 8.875 % 55 8.875 % Senior notes due 7/1/2021 89 9.250 % 89 9.250 % Senior notes due 9/15/2021 220 6.250 % 220 6.250 % Senior notes due 4/15/2022 500 8.750 % 500 8.750 % Senior notes due 9/15/2022 2,188 10.500 % 2,188 10.500 % Senior notes due 1/15/2023 850 7.125 % 850 7.125 % Senior notes due 4/15/2024 750 7.625 % 750 7.625 % Senior notes due 1/15/2025 775 6.875 % 775 6.875 % Senior notes due 9/15/2025 3,600 11.000 % 3,600 11.000 % Debentures due 11/1/2025 138 7.000 % 138 7.000 % Debentures due 8/15/2026 2 6.800 % 2 6.800 % Senior notes due 1/15/2027 346 7.875 % 346 7.875 % Senior notes due 8/15/2031 945 9.000 % 945 9.000 % Debentures due 10/1/2034 1 7.680 % 1 7.680 % Debentures due 7/1/2035 125 7.450 % 125 7.450 % Debentures due 10/1/2046 193 7.050 % 193 7.050 % Total unsecured debt issued by Frontier 10,949 10,949 Secured debt issued by subsidiaries Debentures due 11/15/2031 100 8.500 % 100 8.500 % RUS loan contracts due 1/3/2028 6 6.154 % 6 6.154 % Total secured debt issued by subsidiaries 106 106 Unsecured debt issued by subsidiaries Debentures due 5/15/2027 200 6.750 % 200 6.750 % Debentures due 2/1/2028 300 6.860 % 300 6.860 % Debentures due 2/15/2028 200 6.730 % 200 6.730 % Debentures due 10/15/2029 50 8.400 % 50 8.400 % Total unsecured debt issued by subsidiaries 750 750 Debt prior to reclassification to liabilities subject to compromise 16,769 8.188 % (3) 17,516 8.486 % (3) Less: debt subject to compromise ( 10,949 ) - Total Debt $ 5,820 5.944 % (3) $ 17,516 8.486 % (3) (1) Represents borrowings under the JPM Credit Agreement Revolver, as defined below. (2) Represents borrowings under the JPM Credit Agreement Term Loan B, as defined below. (3) Interest rate represents a weighted average of the stated interest rates of multiple issuances .

Restructuring And Other Charg_2

Restructuring And Other Charges (Tables)	12 Months Ended
Restructuring And Other Charges (Tables)	Dec. 31, 2020
Restructuring And Other Charges [Abstract]
Changes In Restructuring Reserve	Restructuring ($ in millions) Liability Balance at December 31, 2018 $ 18 Severance expense 38 Transformation costs 46 Other costs 40 Cash payments during the period ( 127 ) Balance at December 31, 2019 15 Severance expense 7 Transformation costs 8 Other costs 72 Cash payments during the period ( 100 ) Balance at December 31, 2020 $ 2

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2020
Leases [Abstract]
Components Of Lease Cost	For the year ended ( $ in millions ) December 31, 2020 December 31, 2019 Lease cost: Finance lease cost: Amortization of right-of-use assets $ 15 $ 19 Interest on lease liabilities 13 15 Finance lease cost 28 34 Operating lease cost (1) 68 79 Sublease income ( 11 ) ( 11 ) Total Lease cost $ 85 $ 102 (1) Includes short-term lease costs of $ 2 million and $ 3 million and variable lease costs of $ 6 million and $ 6 million for the years ended December 31, 2020 and 2019, respectively.
Supplemental Balance Sheet Information Related To Leases	( $ in millions ) December 31, 2020 December 31, 2019 Operating right-of-use assets $ 215 (1) $ 204 (1) Finance right-of-use assets $ 143 (2) $ 167 (2) Operating lease liabilities $ 223 (3) $ 211 (3) Finance lease liabilities $ 145 (4) $ 167 (4) Operating leases: Weighted-average remaining lease term 7.75 years 7.54 years Weighted-average discount rate 8.26 % 8.25 % Finance leases: Weighted-average remaining lease term 8.96 years 9.10 years Weighted-average discount rate 8.13 % 7.98 % (1) Operating ROU assets are included in Other assets on our consolidated balance sheet. (2) Finance ROU assets are included in Property, plant, and equipment on our December 31, 2020 consolidated balance sheets. (3) This amount represents $ 48 million and $ 44 million, and $ 175 million and $ 167 million, included in other current liabilities and other liabilities, respectively, on our December 31, 2020 and 2019 consolidated balance sheets. (4) This amount represents $ 21 million and $ 25 million, and $ 124 million and $ 142 million, included in other current liabilities and other liabilities, respectively, on our December 31, 2020 and 2019 consolidated balance sheets.
Supplemental Cash Flow Information Related To Leases	For the year ended ( $ in millions ) December 31, 2020 December 31, 2019 Cash paid for amount included in the measurement of lease liabilities, net of amounts received as revenue: Operating cash flows provided by operating leases $ 67 $ 70 Operating cash flows used by operating leases $ ( 68 ) $ ( 76 ) Operating cash flows used by finance leases $ ( 13 ) $ ( 15 ) Financing cash flows used by finance leases $ ( 23 ) $ ( 35 ) Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 28 $ 42 Finance leases $ 3 $ 34
Maturity Analysis For Operating And Finance Lease Liabilities	Operating Finance ( $ in millions ) Leases Leases Future maturities: 2021 $ 49 $ 32 2022 47 27 2023 42 23 2024 38 16 2025 32 14 Thereafter 87 82 Total lease payments 295 194 Less: imputed interest ( 72 ) ( 49 ) Present value of lease liabilities $ 223 $ 145 (2)
Maturity Analysis For Operating Leases From Customers	Operating ( $ in millions ) Lease Payments Future maturities of lease payments from customers: 2021 $ 10 2022 10 2023 10 2024 7 2025 1 Thereafter 1 Total lease payments from customers $ 39

Investment And Other Income (_2

Investment And Other Income (Loss), Net (Tables)	12 Months Ended
Investment And Other Income (Loss), Net (Tables)	Dec. 31, 2020
Investment And Other Income (Loss), Net [Abstract]
Components Of Investment And Other Income (Loss), Net	For the year ended December 31, ( $ in millions ) 2020 2019 2018 Interest and dividend income $ 4 $ 9 $ 6 Pension and OPEB benefit (costs) ( 43 ) ( 42 ) 10 All other, net ( 4 ) ( 4 ) ( 3 ) Total investment and other income (loss), net $ ( 43 ) $ ( 37 ) $ 13

Stock Plans (Tables)

Stock Plans (Tables)	12 Months Ended
Stock Plans (Tables)	Dec. 31, 2020
Stock Plans [Abstract]
LTIP Target Performance Shares	Number of Shares (in thousands) Balance at December 31, 2017 306 LTIP target performance shares granted 284 LTIP target performance shares earned ( 18 ) LTIP target performance shares forfeited ( 75 ) Balance at December 31, 2018 497 LTIP target performance shares granted - LTIP target performance shares earned ( 381 ) LTIP target performance shares forfeited ( 20 ) Balance at December 31, 2019 96 LTIP target performance shares/units granted - LTIP target performance shares/units earned - LTIP target performance shares/units forfeited ( 96 ) Balance at December 31, 2020 -
Restricted Shares Outstanding	Weighted Average Number of Grant Date Aggregate Shares Fair Value Fair Value (in thousands) (per share) (in millions) Balance at December 31, 2017 633 $ 58.63 $ 4 Restricted stock granted 2,023 $ 8.26 $ 5 Restricted stock vested ( 221 ) $ 66.82 $ ( 1 ) Restricted stock forfeited ( 577 ) $ 16.47 Balance at December 31, 2018 1,858 $ 16.02 $ 4 Restricted stock granted 105 $ 2.00 $ - Restricted stock vested ( 1,039 ) $ 19.05 $ ( 1 ) Restricted stock forfeited ( 24 ) $ 28.30 Balance at December 31, 2019 900 $ 10.57 $ 1 Restricted stock granted - $ 0.00 $ - Restricted stock vested ( 387 ) $ 15.04 $ - Restricted stock forfeited ( 209 ) $ 7.79 Balance at December 31, 2020 304 $ 6.78 $ -

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2020
Income Taxes [Abstract]
Reconciliation Of Provision For Income Taxes	2020 2019 2018 Consolidated tax provision at federal statutory rate 21.0 % 21.0 % 21.0 % State income tax provisions, net of federal income tax benefit 21.7 2.6 1.6 Tax reserve adjustment ( 0.7 ) - 0.1 Changes in certain deferred tax balances ( 35.8 ) ( 2.3 ) ( 3.5 ) Interest expense deduction 30.7 - - Restructuring cost ( 10.0 ) - - Goodwill impairment - ( 11.8 ) ( 10.4 ) Loss on disposal of Northwest Operations ( 9.1 ) - - Share-based payments ( 0.2 ) ( 0.1 ) ( 0.5 ) Federal research and development credit ( 0.5 ) - 0.1 Deferred Tax Remeasurement - 2017 Tax Reform - - 0.6 All other, net 0.1 - ( 0.2 ) Effective tax rate 17.2 % 9.4 % 8.8 %
Components Of Net Deferred Income Tax Liability (Asset)	( $ in millions ) 2020 2019 Deferred income tax liabilities: Property, plant and equipment basis differences $ 1,873 $ 2,184 Deferred revenue/expense 44 65 Other, net 56 56 $ 1,973 $ 2,305 Deferred income tax assets: Pension liability $ 308 $ 256 Intangibles 681 665 Tax operating loss carryforward 923 898 Employee benefits 207 184 Interest expense deduction limitation carryforward 44 238 Accrued expenses 75 37 Lease obligations 83 92 Tax credit 40 39 Allowance for doubtful accounts 35 32 Other, net 17 7 2,413 2,448 Less: Valuation allowance ( 783 ) ( 605 ) Net deferred income tax asset 1,630 1,843 Net deferred income tax liability $ 343 $ 462
Schedule Of Components Of Income Tax Expense (Benefit)	( $ in millions ) 2020 2019 2018 Income tax expense (benefit): Current: Federal $ ( 12 ) $ 1 $ ( 1 ) State 19 7 6 Total Current 7 8 5 Deferred: Federal ( 84 ) ( 606 ) ( 77 ) State ( 7 ) ( 13 ) 10 Total Deferred ( 91 ) ( 619 ) ( 67 ) Total income tax benefit ( 84 ) ( 611 ) ( 62 ) Income taxes charged (credited) to equity of Frontier: Deferred income taxes (benefits) arising from the recognition of additional pension/OPEB liability 35 32 ( 31 ) Total income taxes charged (credited) to equity of Frontier 35 32 ( 31 ) Total income tax benefit $ ( 49 ) $ ( 579 ) $ ( 93 )
Changes In The Balance Of Unrecognized Tax Benefits	($ in millions) 2020 2019 Unrecognized tax benefits - beginning of year $ 12 $ 11 Gross increases - prior year tax positions 4 - Gross increases - current year tax positions - 1 Gross decreases - FIN 48 liability release - - Gross decreases - expired statute of limitations - - Unrecognized tax benefits - end of year $ 16 $ 12

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
Net Loss Per Common Share (Tables)	Dec. 31, 2020
Net Loss Per Common Share [Abstract]
Calculation Of Net Loss Per Common Share	( $ in millions and shares in thousands, except per share amounts ) 2020 2019 2018 Net loss used for basic and diluted earnings (loss) per share: Net loss attributable to Frontier common shareholders $ ( 402 ) $ ( 5,911 ) $ ( 750 ) Less: Dividends paid on unvested restricted stock awards - - - Total basic net loss attributable to Frontier common shareholders $ ( 402 ) $ ( 5,911 ) $ ( 750 ) Effect of loss related to dilutive stock units - - - Total diluted net loss attributable to Frontier common shareholders $ ( 402 ) $ ( 5,911 ) $ ( 750 ) Basic earnings (loss) per share: Total weighted average shares and unvested restricted stock awards outstanding - basic 104,944 105,356 91,523 Less: Weighted average unvested restricted stock awards ( 477 ) ( 1,291 ) ( 1,840 ) Total weighted average shares outstanding - basic 104,467 104,065 89,683 Basic net loss per share attributable to Frontier common shareholders $ ( 3.85 ) $ ( 56.80 ) $ ( 8.37 ) Diluted earnings (loss) per share: Total weighted average shares outstanding - basic 104,467 104,065 89,683 Effect of dilutive shares - - - Total weighted average shares outstanding - diluted 104,467 104,065 89,683 Diluted net loss per share attributable to Frontier common shareholders $ ( 3.85 ) $ ( 56.80 ) $ ( 8.37 )

Comprehensive Loss (Tables)

Comprehensive Loss (Tables)	12 Months Ended
Comprehensive Loss (Tables)	Dec. 31, 2020
Comprehensive Loss [Abstract]
Accumulated Other Comprehensive Income (Loss), Net Of Tax	($ in millions) Pension Costs OPEB Costs Total Balance at December 31, 2017 (1) $ ( 345 ) $ ( 21 ) $ ( 366 ) Other comprehensive income (loss) before reclassifications ( 191 ) 51 ( 140 ) Amounts reclassified from accumulated other comprehensive income (loss) 47 ( 4 ) 43 Net current-period other comprehensive income (loss) ( 144 ) 47 ( 97 ) Balance at December 31, 2018 (1) ( 489 ) 26 ( 463 ) Other comprehensive income (loss) before reclassifications ( 201 ) 17 ( 184 ) Amounts reclassified from accumulated other comprehensive income (loss) 89 ( 13 ) 76 Net current-period other comprehensive income (loss) ( 112 ) 4 ( 108 ) Impact of adoption of ASU 2018-02 ( 83 ) 4 ( 79 ) Balance at December 31, 2019 (1) ( 684 ) $ 34 $ ( 650 ) Other comprehensive income (loss) before reclassifications ( 320 ) ( 76 ) ( 396 ) Amounts reclassified from accumulated other comprehensive income (loss) 305 ( 14 ) 291 Net current-period other comprehensive income (loss) ( 15 ) ( 90 ) ( 105 ) Balance at December 31, 2020 (1) $ ( 699 ) $ ( 56 ) $ ( 755 ) (1) Pension and OPEB amounts are net of deferred tax balances of $ 234 million, $ 204 million, $ 250 million and $ 223 million as of December 31, 2020, 2019, 2018, and 2017, respectively.
Reclassification Out Of AOCI	Amount Reclassified from ($ in millions) Accumulated Other Comprehensive Loss (1) Affected Line Item in the Details about Accumulated Other Statement where Comprehensive Loss Components 2020 2019 2018 Net loss is Presented Amortization of Pension Cost Items (2) Actuarial gains (losses) $ ( 99 ) $ ( 58 ) $ ( 24 ) Loss on disposal ( 81 ) - - Pension settlement costs ( 159 ) ( 57 ) ( 41 ) Reclassifications, pretax ( 339 ) ( 115 ) ( 65 ) Loss before income taxes Tax Impact 34 26 18 Income tax (expense) benefit Reclassifications, net of tax $ ( 305 ) $ ( 89 ) $ ( 47 ) Net loss Amortization of OPEB Cost Items (2) Prior-service credits (costs) $ 32 $ 11 $ 9 Actuarial gains (losses) ( 6 ) 4 ( 3 ) Loss on disposal ( 7 ) - - Reclassifications, pretax 19 15 6 Loss before income taxes Tax impact ( 5 ) ( 2 ) ( 2 ) Income tax (expense) benefit Reclassifications, net of tax $ 14 $ 13 $ 4 Net loss (1) Amounts in parentheses indicate losses. (2) These accumulated other comprehensive loss components are included in the computation of net periodic pension and OPEB costs (see Note 20 - Retirement Plans for additional details).

Quarterly Financial Data (Table

Quarterly Financial Data (Tables)	12 Months Ended
Quarterly Financial Data (Tables)	Dec. 31, 2020
Quarterly Financial Data [Abstract]
Schedule Of Quarterly Financial Data	2020 First Second Third Fourth Total ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year Revenue $ 1,933 $ 1,801 $ 1,726 $ 1,695 $ 7,155 Operating income (3) $ 272 $ 140 $ 270 $ 277 $ 959 Net earnings (loss) attributable to Frontier common shareholders (2)(3) $ ( 186 ) $ ( 181 ) $ 15 $ ( 50 ) $ ( 402 ) Basic and diluted net earnings (loss) per share attributable to Frontier common shareholders (1)(2)(3) $ ( 1.78 ) $ ( 1.73 ) $ 0.14 $ ( 0.48 ) $ ( 3.85 ) (1) The quarterly net loss per share amounts are rounded to the nearest cent. Annual net loss per share may vary depending on the effect of such rounding. (2) During 2020, Frontier recorded $ 409 million in reorganization items, net ($ 361 million net of tax) in connection with the Restructuring Plan. (3) During 2020, we recorded aggregate losses on the disposal of our Northwest Operations of $ 162 million ($ 118 million after-tax). Refer to Note 7 for further details 2019 First Second Third Fourth Total ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year Revenue (3) $ 2,101 $ 2,067 $ 1,997 $ 1,942 $ 8,107 Operating income (loss) (2)(3) $ 339 $ ( 5,459 ) $ 26 $ 221 $ ( 4,873 ) Net loss attributable to Frontier common shareholders (2)(3) $ ( 87 ) $ ( 5,317 ) $ ( 345 ) $ ( 162 ) $ ( 5,911 ) Basic and diluted net loss per share attributable to Frontier common shareholders (1)(2)(3) $ ( 0.84 ) $ ( 51.07 ) $ ( 3.31 ) $ ( 1.55 ) $ ( 56.80 ) (1) The quarterly net loss per share amounts are rounded to the nearest cent. Annual net loss per share may vary depending on the effect of such rounding. (2) During 2019, we recorded aggregate goodwill impairment charges of $ 5,725 million ($ 5,201 million after-tax). Refer to Note 8 for further details. (3) During 2019, we recorded aggregate losses on the disposal of our Northwest Operations of $ 446 million ($ 446 million after-tax). Refer to Note 7 for further details.

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
Retirement Plans (Tables)	Dec. 31, 2020
Retirement Plans [Abstract]
Projected Benefit Obligation, Fair Values Of Plan Assets And Amounts Recognized In The Balance Sheet	( $ in millions ) 2020 2019 Change in projected benefit obligation (PBO) PBO at beginning of year $ 3,726 $ 3,173 Service cost 95 82 Interest cost 108 130 Actuarial (gain) loss 506 603 Benefits paid ( 73 ) ( 65 ) Impact of Divestiture of Northwest Operations (1) ( 189 ) - Settlements ( 465 ) ( 235 ) Special termination benefits - 38 PBO at end of year $ 3,708 $ 3,726 Change in plan assets Fair value of plan assets at beginning of year $ 2,730 $ 2,348 Fair value of plan assets for the Northwest Operations ( 70 ) - Actual return on plan assets 321 516 Employer contributions 64 166 Settlements ( 465 ) ( 235 ) Benefits paid ( 73 ) ( 65 ) Fair value of plan assets at end of year $ 2,507 $ 2,730 Funded status $ ( 1,201 ) $ ( 996 ) Amounts recognized in the consolidated balance sheet Pension and other postretirement benefits - current $ - $ - Pension and other postretirement benefits - noncurrent $ ( 1,201 ) $ ( 996 ) Accumulated other comprehensive loss $ 915 $ 899 (1) Includes a gain of $ 20 million related to the elimination of future compensation increases as a result of the divestiture of the Northwest Operations.
Net Periodic Benefit Cost	( $ in millions ) 2020 2019 2018 Components of total pension benefit cost Service cost $ 95 $ 82 $ 90 Interest cost on projected benefit obligation 108 130 125 Expected return on plan assets ( 171 ) ( 172 ) ( 192 ) Amortization of unrecognized loss 99 58 24 Net periodic pension benefit cost 131 98 47 Pension settlement costs 159 57 41 Pension special termination benefit enhancements - 38 - Gain on disposal, net ( 38 ) - - Total pension benefit cost $ 252 $ 193 $ 88
Weighted Average Asset Allocations, By Asset Category	2020 2019 Asset category: Equity securities 49 % 49 % Debt securities 37 % 39 % Alternative investments 14 % 12 % Total 100 % 100 %
Expected Benefit Payments Over The Next Ten Years	($ in millions) Amount 2021 $ 255 2022 252 2023 253 2024 256 2025 257 2026-2030 1,239 Total $ 2,512
Schedule Of Assumptions Used	2020 2019 2018 Discount rate - used at year end to value obligation 2.60 % 3.40 % 4.30 % Discount rate - used at beginning of year to compute annual cost 3.40 % 4.30 % 3.70 % Expected long-term rate of return on plan assets 7.50 % 7.50 % 7.50 % Rate of increase in compensation levels 2.00 % 2.00 % 2.00 %
Schedule Of Changes In Projected benefit Obligations For OPEB	( $ in millions) 2020 2019 Change in benefit obligation Benefit obligation at beginning of year $ 972 $ 965 Impact of Divestiture of Northwest Operations ( 31 ) - Service cost 20 20 Interest cost 33 41 Plan amendments - ( 149 ) Plan participants' contributions 9 7 Actuarial loss 100 129 Benefits paid ( 61 ) ( 47 ) Special termination benefits - 6 Benefit obligation at end of year $ 1,042 $ 972 Change in plan assets Fair value of plan assets at beginning of year $ - $ - Plan participants' contributions 9 7 Employer contribution 52 40 Benefits paid ( 61 ) ( 47 ) Fair value of plan assets at end of year $ - $ - Funded status $ ( 1,042 ) $ ( 972 ) Amounts recognized in the consolidated balance sheet Pension and other postretirement benefits - current $ ( 48 ) $ ( 43 ) Pension and other postretirement benefits - noncurrent $ ( 994 ) $ ( 900 ) Pension and other postretirement benefits - AHFS* $ - $ ( 29 ) Accumulated other comprehensive (gain) loss $ 74 $ ( 45 ) * Assets Held for Sale
Schedule Of Net Benefit Costs For OPEB	( $ in millions ) 2020 2019 2018 Components of total postretirement benefit cost Service cost $ 20 $ 20 $ 21 Interest cost on projected benefit obligation 33 41 38 Amortization of prior service credit ( 32 ) ( 11 ) ( 9 ) Amortization of unrecognized (gain) loss 6 ( 4 ) 3 Net periodic postretirement benefit cost 27 46 53 OPEB special termination benefit enhancements - 6 - Gain on disposal, net ( 24 ) - - Total postretirement benefit cost $ 3 $ 52 $ 53
Schedule Of Assumptions Used For OPEB	2020 2019 2018 Discount rate - used at year end to value obligation 2.60 % - 2.80 % 3.40 % - 3.50 % 4.30 % - 4.40 % Discount rate - used to compute annual cost 3.40 % - 3.50 % 4.30 % - 4.40 % 3.70 % - 3.80 %
Schedule Of Expected Benefit Payments For OPEB	($ in millions) Gross Benefit Medicare Part D Subsidy Total 2021 $ 49 $ - $ 49 2022 48 - 48 2023 48 - 48 2024 52 - 52 2025 48 - 48 2026-2030 278 2 280 Total $ 523 $ 2 $ 525
Net Periodic Benefit Cost Not Yet Recognized	Pension Plan OPEB ( $ in millions ) 2020 2019 2020 2019 Net actuarial loss $ 915 $ 899 $ 192 $ 105 Prior service credit - - ( 118 ) ( 150 ) Total $ 915 $ 899 $ 74 $ ( 45 )
Amounts Recognized As A Component Of AOCI	Pension Plan OPEB ( $ in millions ) 2020 2019 2020 2019 Accumulated other comprehensive (gain) loss at beginning of year $ 899 $ 754 $ ( 45 ) $ ( 41 ) Net actuarial (gain) loss amortized during year ( 99 ) ( 58 ) ( 6 ) 4 Net loss on disposal recognized during the year ( 81 ) - ( 7 ) - Prior service credit amortized during year - - 32 11 Prior service credit occurring during year - - - ( 149 ) Net actuarial loss occurring during year 355 260 100 130 Settlement loss recognized ( 159 ) ( 57 ) - - Net amount recognized in comprehensive income (loss) for the year 16 145 119 ( 4 ) Accumulated other comprehensive (gain) loss at end of year $ 915 $ 899 $ 74 $ ( 45 )

Fair Value Of Financial Instr_2

Fair Value Of Financial Instruments (Tables)	12 Months Ended
Fair Value Of Financial Instruments (Tables)	Dec. 31, 2020
Fair Value Of Financial Instruments [Abstract]
Pension Plan Assets Measured At Fair Value On Recurring Basis	Fair Value Measurements at December 31, 2020 ( $ in millions ) Total Level 1 Level 2 Level 3 Cash and Cash Equivalents $ 55 $ 55 $ - $ - U.S. Government Obligations 48 - 48 - Corporate and Other Obligations 506 - 506 - Common Stock 510 510 - - Preferred Stock 3 3 - - Interest in Registered Investment Companies (1) 140 140 - - Interest in Limited Partnerships and Limited Liability Companies 166 - - 166 Total investments at fair value $ 1,428 $ 708 $ 554 $ 166 Common/Collective Trusts (1) 1,073 Interest in Registered Investment Companies (1) 32 Interest and Dividend Receivable 5 Due from Broker for Securities Sold 22 Receivable Associated with Insurance Contract 7 Due to Broker for Securities Purchased ( 60 ) Total Plan Assets, at Fair Value $ 2,507 Fair Value Measurements at December 31, 2019 ( $ in millions ) Total Level 1 Level 2 Level 3 Cash and Cash Equivalents $ 46 $ 46 $ - $ - U.S. Government Obligations 39 - 39 - Corporate and Other Obligations 547 - 547 - Common Stock 552 552 - - Preferred Stock 4 4 - - Interest in Registered Investment Companies (1) 150 150 - - Interest in Limited Partnerships and Limited Liability Companies 163 - - 163 Total investments at fair value $ 1,501 $ 752 $ 586 $ 163 Common/Collective Trusts (1) 1,177 Interest in Registered Investment Companies (1) 87 Interest and Dividend Receivable 6 Due from Broker for Securities Sold 61 Receivable Associated with Insurance Contract 7 Due to Broker for Securities Purchased ( 109 ) Total Plan Assets, at Fair Value $ 2,730 (1) Investments that are measured at fair value using the net asset value (NAV) practical expedient have not been classified in the fair value hierarchy. The fair value of common/collective trusts are estimated using the NAV per share multiplied by the number of shares of the trust investment held as of the measurement date. Additionally, the fair value of certain assets totaling $ 32 million and $ 87 million, as of December 31, 2020 and 2019, respectively, included in “Interest in Registered Investment Companies” were estimated using the NAV practical expedient. These balances are intended to permit reconciliation of the fair value hierarchy to the plan asset amounts presented in Note 20 - Retirement Plans.
Changes In Fair Value of Plan's Level 3 Assets	Interest in Limited Partnerships and Limited Liability Companies ( $ in millions ) 2020 2019 Balance at beginning of year $ 163 $ 155 Realized gains 14 14 Unrealized gains 3 8 Sales and distributions ( 14 ) ( 14 ) Balance at end of year $ 166 $ 163
Redemption Of The Plan's Level 3 Investments	Liquidation Capitalization ( $ in millions ) Fair Value Period Rate Interest in Limited Partnerships and Limited Liability Companies (4) MS IFHF SVP LP Cayman (1) $ 1 4 years N/A RII World Timberfund, LLC (2) 5 2 years N/A 426 E. Casino Road, LLC (3) 17 N/A 7.00 % 100 Comm Drive, LLC (3) 10 N/A 7.75 % 100 CTE Drive, LLC (3) 11 N/A 9.50 % 6430 Oakbrook Parkway, LLC (3) 27 N/A 7.75 % 8001 West Jefferson, LLC (3) 29 N/A 8.75 % 1500 MacCorkle Ave SE, LLC (3) 15 N/A 8.75 % 400 S. Pike Road West, LLC (3) 1 N/A 8.50 % 601 N. US 131, LLC (3) 1 N/A 9.50 % 9260 E. Stockton Blvd., LLC (3) 7 N/A 7.25 % 120 E. Lime Street, LLC (3) 9 N/A 9.00 % 610 N. Morgan Street, LLC (3) 33 N/A 8.50 % Total Interest in Limited Partnerships and Limited Liability Companies $ 166 (1) The partnerships’ investment objective is to seek capital appreciation principally through investing in investment funds managed by third party investment managers who employ a variety of alternative investment strategies. These instruments are subject to certain withdrawal restrictions. The Plan is in the process of liquidating its interest in the partnerships and distributions are expected to be made over the next four years . (2) The fund’s objective is to realize substantial long-term capital appreciation by investing in timberland properties primarily in South America and Australia. This investment is subject to certain withdrawal restrictions. In 2019, the fund entered into liquidation period of the partnerships and distributions are expected to be made over the next two years . (3) The entity invests in commercial real estate properties that are leased to Frontier. The leases are triple net, whereby Frontier is responsible for all expenses, including but not limited to, insurance, repairs and maintenance and payment of property taxes. (4) All Level 3 investments have the same redemption frequency (through the liquidation of underlying investments) and redemption notice period (none). The fair value of these properties is based on independent appraisals.
Fair Value Of Long-Term Debt	2020 2019 Carrying Carrying ($ in millions) Amount Fair Value Amount Fair Value Total debt $ 16,769 $ 11,635 $ 17,516 $ 12,026

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2020
Commitments And Contingencies [Abstract]
Future Payments For Obligations Under Noncancelable Long Distance Contracts And Service Agreements	($ in millions) Amount Year ending December 31: 2021 $ 85 2022 22 2023 19 2024 4 2025 2 Thereafter 4 Total $ 136
Outstanding Performance Letters Of Credit	($ in millions) Amount CNA Financial Corporation (CNA) $ 49 AIG Insurance 28 Zurich (1) 62 Total $ 139 (1) Zurich letters of credit exclude approximately $57 million of cash held in trust in lieu of issuing letters of credit.

Description Of Business And S_3

Description Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) customer in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)employeestatecustomer	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Mar. 19, 2018	Dec. 31, 2015state
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of customers \| customer	3.6
Number of subscribers \| customer	3.1
Number of employees \| employee	16,200
Number of states of operation \| state	25
Interest rate	5.944%
Restricted cash	$ 58	$ 50
Expected customer life	4 years
Customer surcharges	$ 193	221	$ 213
Video franchise fees	$ 30	$ 40	$ 47
First Lien Notes due April 2027 [Member] \| Secured Debt [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Interest rate	8.00%
Maturity date	Apr. 1, 2027
Second Lien Notes Due 4/1/2026 [Member] \| Secured Debt [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Interest rate	8.50%	8.50%		8.50%
Maturity date	Apr. 1, 2026
CAF Phase II [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of states of operation \| state	25				29
Funding term	7 years
RDOF Program [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Funding term	10 years

Chapter 11 Filing And Other R_3

Chapter 11 Filing And Other Related Matters (Narrative) (Details) - USD ($)	Nov. 25, 2020	Oct. 08, 2020	Aug. 27, 2020	Aug. 13, 2020	May 15, 2020	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2019
Reorganization [Line Items]
Interest rate						5.944%
Principal Outstanding						$ 16,769,000,000		$ 17,516,000,000
JP Morgan Revolving Credit Facility [Member]
Reorganization [Line Items]
Maturity date						Feb. 27, 2024
Debt instrument, face amount						$ 850,000,000
JP Morgan Term Loan B [Member]
Reorganization [Line Items]
Maturity date						Jun. 15, 2024
Debt instrument, face amount	$ 1,740,000,000					$ 1,740,000,000
Secured Debt [Member]
Reorganization [Line Items]
Principal Outstanding						4,964,000,000		5,711,000,000
Unsecured Debt [Member]
Reorganization [Line Items]
Principal Outstanding						10,949,000,000		10,949,000,000
Secured Subsidiary Debt [Member]
Reorganization [Line Items]
Reorganization plan, Interest rate			2.50%
Principal Outstanding						106,000,000		106,000,000
Unsecured Subsidiary Debt [Member]
Reorganization [Line Items]
Takeback Debt, Principal amount			$ 750,000,000
Reorganization plan, Interest rate			3.50%
Principal Outstanding						750,000,000		$ 750,000,000
Term Loan B [Member]
Reorganization [Line Items]
Payments to holders						48,000,000
Original First Lien Notes [Member]
Reorganization [Line Items]
Payments to holders						9,000,000
Debt instrument, face amount		$ 1,650,000,000
Original Second Lien Notes [Member]
Reorganization [Line Items]
Debt instrument, face amount	1,600,000,000
Term Loan B, Second Payment [Member]
Reorganization [Line Items]
Payments to holders						$ 8,000,000
DIP Revolving Facility [Member]
Reorganization [Line Items]
DIP, Maximum line of credit		625,000,000		$ 625,000,000	$ 460,000,000
DIP Revolving Facility [Member] \| Secured Debt [Member]
Reorganization [Line Items]
DIP, Maximum line of credit		500,000,000
DIP Term Loan Facility [Member]
Reorganization [Line Items]
DIP, Maximum line of credit	$ 750,000,000	$ 500,000,000
Debenture Due 5/15/2027 [Member] \| Unsecured Subsidiary Debt [Member]
Reorganization [Line Items]
Interest rate						6.75%
Maturity date						May 15, 2027
Debenture Due 2/1/2028 [Member] \| Unsecured Subsidiary Debt [Member]
Reorganization [Line Items]
Interest rate						6.86%
Maturity date						Feb. 1, 2028
Debenture Due 2/15/2028 [Member] \| Unsecured Subsidiary Debt [Member]
Reorganization [Line Items]
Interest rate						6.73%
Maturity date						Feb. 15, 2028
Debenture Due 10/15/2029 [Member] \| Unsecured Subsidiary Debt [Member]
Reorganization [Line Items]
Interest rate						8.40%
Maturity date						Oct. 15, 2029
Debenture Due 11/15/2031 [Member] \| Secured Subsidiary Debt [Member]
Reorganization [Line Items]
Interest rate						8.50%
Maturity date						Nov. 15, 2031
Senior Notes Due 10/1/2018 [Member] \| Unsecured Debt [Member]
Reorganization [Line Items]
Interest rate							8.125%
Maturity date						Oct. 1, 2018	Oct. 1, 2018
Senior Note Due 3/15/2019 [Member] \| Unsecured Debt [Member]
Reorganization [Line Items]
Interest rate							7.125%
Maturity date							Mar. 15, 2019
New First Lien Notes [Member]
Reorganization [Line Items]
Interest rate		5.875%
Maturity date		Oct. 15, 2027
Principal Outstanding		$ 1,150,000,000
First Lien Notes Due May 2028 [Member]
Reorganization [Line Items]
Interest rate	5.00%
Maturity date	May 1, 2028
Principal Outstanding	$ 1,550,000,000
Second Lien Notes Due May 2029 [Member]
Reorganization [Line Items]
Interest rate	6.75%
Maturity date	May 1, 2029
Principal Outstanding	$ 1,000,000,000
Maximum [Member]
Reorganization [Line Items]
Maturity period			8 years
Minimum [Member]
Reorganization [Line Items]
Maturity period			1 year
Percentage of debt held by the Consenting Noteholders			50.10%

Chapter 11 Filing And Other R_4

Chapter 11 Filing And Other Related Matters (Schedule Of Liabilities Subject To Compromise) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Chapter 11 Filing And Other Related Matters [Abstract]
Accounts payable	$ 57
Other current liabilities	62
Accounts payable and other current liabilities	119
Debt subject to compromise	10,949
Accrued interest on debt subject to compromise	497
Long-term debt and accrued interest	11,446
Liabilities subject to compromise	$ 11,565

Chapter 11 Filing And Other R_5

Chapter 11 Filing And Other Related Matters (Schedule Of Reorganization Items) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Chapter 11 Filing And Other Related Matters [Abstract]
Write-off debt issuance costs and original issue net discount on debt subject to compromise	$ 93
Debtor-in-possession financing costs	121
Secured Creditor Settlement	58
Professional fees and other bankruptcy related costs	137
Reorganization items, net	$ 409

Revenue Recognition (Disaggrega

Revenue Recognition (Disaggregation Of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 6,781	$ 7,738	$ 8,228
Subsidy and other regulatory revenue									374	369	383
Total revenue	$ 1,695	$ 1,726	$ 1,801	$ 1,933	$ 1,942	$ 1,997	$ 2,067	$ 2,101	7,155	8,107	8,611
Lease revenue									67	70	73
Revenue from contracts with customers, performance obligation	$ 2,691								2,691
Data And Internet Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,478	3,756	3,878
Voice Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2,085	2,500	2,721
Video Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									789	1,005	1,085
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									429	477	544
Consumer [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,586	4,153	4,380
Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,195	$ 3,585	$ 3,848
Northwest Operations [Member]
Disaggregation of Revenue [Line Items]
Transition services revenue									$ 30

Revenue Recognition (Summary Of

Revenue Recognition (Summary Of Changes In Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue Recognition [Abstract]
Beginning balance	$ 105	$ 107
Commissions deferred, Current	94	138
Commission costs recognized, Current	(116)	(131)
Reclass to assets held for sale, Current		(9)
Reclassified between Current and Noncurrent, Current	14
Ending balance	97	105
Beginning balance	121	127
Commissions deferred, Noncurrent	13	6
Commission costs recognized, Noncurrent	(4)
Reclass to assets held for sale, Noncurrent		(12)
Reclassified between Current and Noncurrent, Noncurrent	(14)
Ending balance	$ 116	$ 121

Revenue Recognition (Changes In

Revenue Recognition (Changes In Contract Assets And Contract Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue Recognition [Abstract]
Contract current assets, Beginning balance	$ 37	$ 44
Contract current assets, Revenue recognized included in opening contract balance	(34)	(39)
Contract current assets, Credits granted, excluding amounts recognized as revenue	3	30
Contract current assets, Reclassified between Current and Noncurrent		5
Contract current assets, Reclassified to held for sale		(3)
Contract current assets, Ending balance	6	37
Contract noncurrent assets, Beginning balance	8	25
Contract noncurrent assets, Revenue recognized included in opening contract balance		(12)
Contract noncurrent assets, Credits granted, excluding amounts recognized as revenue	1	1
Contract noncurrent assets, Reclassified between Current and Noncurrent		(5)
Contract noncurrent assets, Reclassified to held for sale		(1)
Contract noncurrent assets, Ending balance	9	8
Contract current liabilities, Beginning balance	41	49
Contract current liabilities, Revenue recognized included in opening contract balance	(68)	(81)
Contract current liabilities, Cash received, excluding amounts recognized as revenue	85	78
Contract current liabilities, Reclassified to held for sale		(5)
Contract current liabilities, Ending balance	58	41
Contract noncurrent liabilities, Beginning balance	21	22
Contract noncurrent liabilities, Revenue recognized included in opening contract balance	(12)	(17)
Contract noncurrent liabilities, Cash received, excluding amounts recognized as revenue	11	16
Contract noncurrent liabilities, Ending balance	$ 20	$ 21

Revenue Recognition (Performanc

Revenue Recognition (Performance Obligations, Revenue) (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 2,691
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 1,426
Performance obligation satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 651
Performance obligation satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 288
Performance obligation satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 118
Performance obligation satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 139
Performance obligation satisfaction period	1 year

Accounts Receivable (Narrative)

Accounts Receivable (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable [Abstract]
Provision for uncollectible amounts	$ 106	$ 109	$ 93
Recoveries	$ 49	$ 37	$ 9

Accounts Receivable (Accounts R

Accounts Receivable (Accounts Receivable) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: Allowance for doubtful accounts	$ (130)	$ (120)	$ (105)	$ (69)
Accounts receivable, net	553	629
Retail And Wholesale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	608	678
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 75	$ 71

Accounts Receivable (Schedule O

Accounts Receivable (Schedule Of Allowance For Doubtful Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, Beginning of the Period	$ 120	$ 105	$ 69
Adjustments	106	109	93
Increases: Charged to Revenue	106	109	93
Decreases: Write-offs and Customer Credits	(96)	(83)	(89)
Reclassified to Assets Held for Sale		(11)
Allowance for Doubtful Accounts, End of the Period	$ 130	$ 120	105
Impact Of Adoption Of ACS 606 [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Adjustments			$ 32

Property, Plant And Equipment_2

Property, Plant And Equipment (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Capital Leased Assets, Gross		$ 143	$ 167	$ 152
Proceeds from sale of property			27	$ 106	$ 106
Gain on sale of property		10
Property, plant and equipment, net			1,049
Aggregate carrying value of the towers		$ 37
Towers [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sale of property	$ 76
Gain on sale of property	75
Aggregate carrying value of the towers	$ 1
Accounting Standards Update 2016-02 [Member]
Property, Plant and Equipment [Line Items]
Deferred gain, Net			$ 11

Property, Plant, And Equipment

Property, Plant, And Equipment (Property, Plant And Equipment, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 27,695	$ 26,552
Less: Accumulated depreciation	(14,764)	(13,589)
Property, plant and equipment, net	12,931	12,963
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	212	217
Buildings and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 2,139	2,171
Estimated useful lives	40 years
General Support [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,643	1,624
General Support [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	15 years
General Support [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Central Office Electronic Circuit Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 8,270	7,968
Central Office Electronic Circuit Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	8 years
Central Office Electronic Circuit Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Poles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,371	1,274
Estimated useful lives	30 years
Cable, Fiber and Wire [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 11,883	11,312
Cable, Fiber and Wire [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Cable, Fiber and Wire [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	15 years
Conduit [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,619	1,608
Estimated useful lives	50 years
Construction Work In Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 558	$ 378

Property, Plant, And Equipmen_2

Property, Plant, And Equipment (Schedule Of Depreciation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Depreciation [Abstract]
Depreciation expense	$ 1,255	$ 1,335	$ 1,385

Divestiture Of Northwest Oper_2

Divestiture Of Northwest Operations (Narrative) (Details) - USD ($) $ in Millions	May 01, 2020	May 28, 2019	Feb. 28, 2021	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Gross proceeds from divestiture		$ 1,352
Net proceeds	$ 1,131				$ 1,131
Escrow to be disbursed					58
Fair value of transition services					30
Net assets	1,132
Property, plant, and equipment, Derecognized	1,084
Goodwill, Derecognized	658
Valuation allowance, Derecognized	603
Defined benefit pension and other postretirement benefit plan obligations, Derecognized	$ 150
Loss on disposal of Northwest Operations					162	$ 446
Out of period adjustment				$ 27
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Escrow to be disbursed			$ 25
Working capital			$ 5
Northwest Operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Transition services revenue					$ 30

Goodwill And Other Intangible_2

Goodwill And Other Intangibles (Narrative) (Details) - USD ($)	3 Months Ended					9 Months Ended	12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Accumulated goodwill impairment charges							$ 9,154,000,000	$ 9,154,000,000
Estimated future amortization expense, year 1							253,000,000
Estimated future amortization expense, year 2							170,000,000
Estimated future amortization expense, year 3							95,000,000
Estimated future amortization expense, year 4							26,000,000
Estimated future amortization expense, year 5							7,000,000
Goodwill associated with planned disposal								658,000,000
Goodwill impairment								5,725,000,000	$ 641,000,000
Infinite-lived intangible impairment							$ 0	$ 0	$ 0
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life							8 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life							12 years
Measurement Input, EBITDA Multiple [Member]
Finite-Lived Intangible Assets [Line Items]
EBITDA multiplier	4.40%	4.40%	5.30%	5.50%	5.50%	5.50%		4.40%
Measurement Input, EBITDA Multiple [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
EBITDA multiplier							4.40%
Measurement Input, EBITDA Multiple [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
EBITDA multiplier							6.50%
Customer Base [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension							3 years 6 months
Royalty Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension							3 months 18 days

Goodwill And Other Intangible_3

Goodwill And Other Intangibles (Components Of Other Intangibles) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets [Line Items]
Gross Carrying Amount, Total	$ 4,526	$ 4,526
Accumulated Amortization	(3,849)	(3,506)
Net Carrying Amount	677	1,020
Trade Name [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Indefinite	122	122
Net Carrying Amount	122	122
Customer Base [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	4,332	4,332
Accumulated Amortization	(3,781)	(3,452)
Net Carrying Amount	551	880
Royalty Agreement [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	72	72
Accumulated Amortization	(68)	(54)
Net Carrying Amount	$ 4	$ 18

Goodwill And Other Intangible_4

Goodwill And Other Intangibles (Schedule Of Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Other Intangibles [Abstract]
Amortization expense	$ 343	$ 445	$ 569

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)

Nov. 25, 2020

Oct. 08, 2020

Aug. 13, 2020

May 15, 2020

Oct. 01, 2018

Jul. 03, 2018

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2016

Mar. 15, 2019

Mar. 19, 2018

Debt Instrument [Line Items]

Interest rate

5.944%

Payment to retire debt instruments

$ 5,697,000,000

Gains (Loss) on early extinguishment of debt

$ (72,000,000)

$ (20,000,000)

$ 32,000,000

Financing obligation for contributions of real property to pension plan

37,000,000

Pension Building Contribution Aggregate Annual Rent

5,000,000

Lease term of contributed property

20 years

Gain (loss) on contribution of property to defined benefit

$ 0

Proceeds from long-term debt borrowings

$ 4,950,000,000

1,650,000,000

1,840,000,000

Remaining outstanding principal

16,769,000,000

$ 17,516,000,000

Sale leaseback transaction

$ 37,000,000

DIP Revolving Facility [Member]

Debt Instrument [Line Items]

DIP, Letters of credit outstanding

$ 90,000,000

DIP, Remaining borrowing capacity

535,000,000

DIP, Maximum line of credit

$ 625,000,000

$ 460,000,000

DIP Revolving Facility [Member] | LIBOR [Member]

Debt Instrument [Line Items]

Interest rate margin

3.25%

DIP Revolving Facility [Member] | Base Rate [Member]

Debt Instrument [Line Items]

Interest rate margin

2.25%

Exit Revolving Facility [Member]

Debt Instrument [Line Items]

Days prior to maturity to meet threshold to not accelerate debt

91 days

Period of conversion

4 years

Exit Revolving Facility [Member] | LIBOR [Member]

Debt Instrument [Line Items]

Interest rate margin

3.50%

Exit Revolving Facility [Member] | Base Rate [Member]

Debt Instrument [Line Items]

Interest rate margin

2.50%

DIP Term Loan Facility [Member]

Debt Instrument [Line Items]

DIP, Remaining borrowing capacity

$ 1,250,000,000

DIP, Maximum line of credit

750,000,000

$ 500,000,000

Proceeds from long-term debt borrowings

$ 750,000,000

DIP Term Loan Facility [Member] | LIBOR [Member]

Debt Instrument [Line Items]

Interest rate margin

4.75%

DIP Term Loan Facility [Member] | Base Rate [Member]

Debt Instrument [Line Items]

Interest rate margin

3.75%

DIP Term Loan Facility [Member] | LIBOR Floor Rate [Member]

Debt Instrument [Line Items]

Interest rate margin

1.00%

Exit Agreement (The Incremental DIP Term Loan Amendment) [Member]

Debt Instrument [Line Items]

DIP, Maximum line of credit

$ 750,000,000

Term Loan Due 06/15/2024 [Member]

Debt Instrument [Line Items]

Proceeds from long-term debt borrowings

$ 240,000,000

Senior Unsecured Debt [Member]

Debt Instrument [Line Items]

Payments to retire debt

117,000,000

Payment to retire debt instruments

$ 2,198,000,000

Senior Unsecured Debt [Member] | Senior Note Due 3/15/2019 [Member]

Debt Instrument [Line Items]

Interest rate

7.125%

Debt Instrument, Maturity Date

Mar. 15,
2020

Payment to retire debt instruments

$ 348,000,000

Secured Debt [Member]

Debt Instrument [Line Items]

Remaining outstanding principal

$ 4,964,000,000

$ 5,711,000,000

Secured Debt [Member] | DIP Revolving Facility [Member]

Debt Instrument [Line Items]

DIP, Maximum line of credit

$ 500,000,000

Secured Debt [Member] | Second Lien Notes Due 4/1/2026 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,600,000,000

Interest rate

8.50%

Debt Instrument, Maturity Date

Apr. 1,
2026

Payment to retire debt instruments

$ 1,600,000,000

Remaining outstanding principal

$ 1,600,000,000

Secured Debt [Member] | Term Loan Due 06/15/2024 [Member]

Debt Instrument [Line Items]

Interest rate

5.55%

Debt Instrument, Maturity Date

Jun. 15,
2024

Remaining outstanding principal

$ 1,699,000,000

Secured Debt [Member] | First Lien Notes Due 4/1/2027 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,650,000,000

Interest rate

8.00%

Debt Instrument, Maturity Date

Apr. 1,
2027

Payment to retire debt instruments

$ 1,650,000,000

Remaining outstanding principal

$ 1,650,000,000

Secured Debt [Member] | Revolver Due 2/27/2024 [Member]

Debt Instrument [Line Items]

Interest rate

4.76%

Debt Instrument, Maturity Date

Feb. 27,
2024

Payment to retire debt instruments

$ 749,000,000

Remaining outstanding principal

$ 749,000,000

Secured Debt [Member] | DIP-to-Exit First Lien Notes Due 10/15/2027 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,150,000,000

Interest rate

5.875%

Debt Instrument, Maturity Date

Oct. 15,
2027

Remaining outstanding principal

$ 1,150,000,000

Maximum percent of redeemable notes

40.00%

Percent of redemption price equal to principal amount

105.875%

Percent of purchase price of the principal amount

101.00%

Secured Debt [Member] | DIP-to-Exit Second Lien Notes Due 5/1/2029 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,000,000,000

Interest rate

6.75%

Debt Instrument, Maturity Date

May 1,
2029

Remaining outstanding principal

$ 1,000,000,000

Maximum percent of redeemable notes

40.00%

Percent of redemption price equal to principal amount

106.75%

Percent of purchase price of the principal amount

101.00%

Secured Debt [Member] | DIP-to-Exit First Lien Notes Due 5/1/2028 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,550,000,000

Interest rate

5.00%

Debt Instrument, Maturity Date

May 1,
2028

Remaining outstanding principal

$ 1,550,000,000

Maximum percent of redeemable notes

40.00%

Percent of redemption price equal to principal amount

105.00%

Percent of purchase price of the principal amount

101.00%

Unsecured Debt [Member]

Debt Instrument [Line Items]

Remaining outstanding principal

$ 10,949,000,000

Unsecured Debt [Member] | Senior Note Due 7/1/2021 [Member]

Debt Instrument [Line Items]

Interest rate

9.25%

Debt Instrument, Maturity Date

Jul. 1,
2021

Remaining outstanding principal

$ 89,000,000

Unsecured Debt [Member] | Senior Note Due 9/15/2021 [Member]

Debt Instrument [Line Items]

Interest rate

6.25%

Debt Instrument, Maturity Date

Sep. 15,
2021

Remaining outstanding principal

$ 220,000,000

Unsecured Debt [Member] | Senior Notes Due 10/1/2018 [Member]

Debt Instrument [Line Items]

Interest rate

8.125%

Debt Instrument, Maturity Date

Oct. 1,
2018

Payments to retire debt

$ 61,000,000

Payment to retire debt instruments

$ 431,000,000

Unsecured Debt [Member] | Senior Note Due 9/15/2020 [Member]

Debt Instrument [Line Items]

Interest rate

8.875%

Debt Instrument, Maturity Date

Sep. 15,
2020

Payment to retire debt instruments

$ 249,000,000

Remaining outstanding principal

$ 55,000,000

Unsecured Debt [Member] | Senior Note Due 3/15/2019 [Member]

Debt Instrument [Line Items]

Interest rate

7.125%

Debt Instrument, Maturity Date

Mar. 15,
2019

Payments to retire debt

$ 56,000,000

Unsecured Debt [Member] | Senior Note Due 4/15/2020 [Member]

Debt Instrument [Line Items]

Interest rate

8.50%

Debt Instrument, Maturity Date

Apr. 15,
2020

Payment to retire debt instruments

$ 447,000,000

Remaining outstanding principal

$ 172,000,000

Unsecured Debt Excluding Open Market Purchases [Member]

Debt Instrument [Line Items]

Payment to retire debt instruments

$ 1,651,000,000

Unsecured Debt Excluding Open Market Purchases [Member] | Senior Note Due 7/1/2021 [Member]

Debt Instrument [Line Items]

Interest rate

9.25%

Payment to retire debt instruments

$ 400,000,000

Unsecured Debt Excluding Open Market Purchases [Member] | Senior Note Due 9/15/2021 [Member]

Debt Instrument [Line Items]

Interest rate

6.25%

Debt Instrument, Maturity Date

Sep. 15,
2021

Payment to retire debt instruments

$ 555,000,000

Unsecured Debt Excluding Open Market Purchases [Member] | Senior Note Due 9/15/2020 [Member]

Debt Instrument [Line Items]

Interest rate

8.875%

Debt Instrument, Maturity Date

Sep. 15,
2020

JP Morgan Term Loan A [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,625,000,000

JP Morgan Revolving Credit Facility [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 850,000,000

Debt Instrument, Maturity Date

Feb. 27,
2024

CoBank Term Loan 2016 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

315,000,000

CoBank Term Loan 2014 [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 350,000,000

JP Morgan Term Loan B [Member]

Debt Instrument [Line Items]

Debt instrument, face amount

$ 1,740,000,000

Debt Instrument, Maturity Date

Jun. 15,
2024

Long-Term Debt (Long-Term Debt)

Long-Term Debt (Long-Term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 17,516
Payments and Retirements	(5,697)
New Borrowings	4,950
Long-term debt, ending balance	16,769	$ 17,516
Less: Debt Issuance Costs		(168)
Less: Debt Premium/(Discount)	(39)	(46)
Debt, less unamortized debt issuance costs and discounts	16,730	17,302
Less: Current Portion	(5,781)	(994)
Less: Debt subject to compromise	$ (10,949)
Total Long-Term Debt		16,308
Interest Rate	8.065%
Secured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 5,711
Long-term debt, ending balance	4,964	5,711
Secured Debt [Member] \| Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	5,711
Payments and Retirements	(5,697)
New Borrowings	4,950
Long-term debt, ending balance	$ 4,964	5,711
Interest Rate	5.747%
Secured Debt [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 106
Long-term debt, ending balance	$ 106	106
Interest Rate	8.368%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 10,949
Long-term debt, ending balance	10,949	10,949
Unsecured Debt [Member] \| Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	10,949
Long-term debt, ending balance	$ 10,949	10,949
Interest Rate	9.193%
Unsecured Debt [Member] \| Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 750
Long-term debt, ending balance	$ 750	$ 750
Interest Rate	6.897%

Long-Term Debt (Schedule Of Uns

Long-Term Debt (Schedule Of Unsecured Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Mar. 15, 2019	Dec. 31, 2018	Mar. 19, 2018
Debt Instrument [Line Items]
Principal Outstanding	$ 16,769	$ 17,516
Less: Debt subject to compromise	(10,949)
Total Debt	$ 5,820	17,516
Interest rate	5.944%
Weighted average interest rate	8.486%
Secured Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 4,964	5,711
Secured Debt [Member] \| Revolver Due 2/27/2024 [Member]
Debt Instrument [Line Items]
Maturity date	Feb. 27, 2024
Principal Outstanding		$ 749
Interest rate		4.76%
Secured Debt [Member] \| Term Loan Due 06/15/2024 [Member]
Debt Instrument [Line Items]
Maturity date	Jun. 15, 2024
Principal Outstanding		$ 1,699
Interest rate		5.55%
Secured Debt [Member] \| First Lien Notes Due 4/1/2027 [Member]
Debt Instrument [Line Items]
Maturity date	Apr. 1, 2027
Principal Outstanding		$ 1,650
Interest rate		8.00%	8.00%
Secured Debt [Member] \| Second Lien Notes Due 4/1/2026 [Member]
Debt Instrument [Line Items]
Maturity date	Apr. 1, 2026
Principal Outstanding		$ 1,600
Interest rate	8.50%	8.50%			8.50%
Secured Debt [Member] \| DIP-to-Exit term loan due 10/8/2027 [Member]
Debt Instrument [Line Items]
Maturity date	Oct. 8, 2027
Principal Outstanding	$ 1,250
Interest rate	5.75%
Secured Debt [Member] \| DIP-to-Exit First Lien Notes Due 10/15/2027 [Member]
Debt Instrument [Line Items]
Maturity date	Oct. 15, 2027
Principal Outstanding	$ 1,150
Interest rate	5.875%
Secured Debt [Member] \| DIP-to-Exit First Lien Notes Due 5/1/2028 [Member]
Debt Instrument [Line Items]
Maturity date	May 1, 2028
Principal Outstanding	$ 1,550
Interest rate	5.00%
Secured Debt [Member] \| DIP-to-Exit Second Lien Notes Due 5/1/2029 [Member]
Debt Instrument [Line Items]
Maturity date	May 1, 2029
Principal Outstanding	$ 1,000
Interest rate	6.75%
Secured Debt [Member] \| IDRB due 5/1/2030 [Member]
Debt Instrument [Line Items]
Maturity date	May 1, 2030
Principal Outstanding	$ 14	$ 13
Interest rate	6.20%	6.20%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 10,949	$ 10,949
Unsecured Debt [Member] \| Senior Note Due 4/15/2020 [Member]
Debt Instrument [Line Items]
Maturity date	Apr. 15, 2020
Principal Outstanding	$ 172	$ 172
Interest rate	8.50%	8.50%		8.50%
Unsecured Debt [Member] \| Senior Note Due 9/15/2020 [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 15, 2020
Principal Outstanding	$ 55	$ 55
Interest rate	8.875%	8.875%
Unsecured Debt [Member] \| Senior Note Due 7/1/2021 [Member]
Debt Instrument [Line Items]
Maturity date	Jul. 1, 2021
Principal Outstanding	$ 89	$ 89
Interest rate	9.25%	9.25%
Unsecured Debt [Member] \| Senior Note Due 9/15/2021 [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 15, 2021
Principal Outstanding	$ 220	$ 220
Interest rate	6.25%	6.25%
Unsecured Debt [Member] \| Senior Note Due 4/15/2022 [Member]
Debt Instrument [Line Items]
Maturity date	Apr. 15, 2022
Principal Outstanding	$ 500	$ 500
Interest rate	8.75%	8.75%
Unsecured Debt [Member] \| Senior Note Due 9/15/2022 [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 15, 2022
Principal Outstanding	$ 2,188	$ 2,188
Interest rate	10.50%	10.50%
Unsecured Debt [Member] \| Senior Note Due 1/15/2023 [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 15, 2023
Principal Outstanding	$ 850	$ 850
Interest rate	7.125%	7.125%
Unsecured Debt [Member] \| Senior Note Due 4/15/2024 [Member]
Debt Instrument [Line Items]
Maturity date	Apr. 15, 2024
Principal Outstanding	$ 750	$ 750
Interest rate	7.625%	7.625%
Unsecured Debt [Member] \| Senior Note Due 1/15/2025 [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 15, 2025
Principal Outstanding	$ 775	$ 775
Interest rate	6.875%	6.875%
Unsecured Debt [Member] \| Senior Note Due 9/15/2025 [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 15, 2025
Principal Outstanding	$ 3,600	$ 3,600
Interest rate	11.00%	11.00%
Unsecured Debt [Member] \| Debentures Due 11/1/2025 [Member]
Debt Instrument [Line Items]
Maturity date	Nov. 1, 2025
Principal Outstanding	$ 138	$ 138
Interest rate	7.00%	7.00%
Unsecured Debt [Member] \| Debentures Due 8/15/2026 [Member]
Debt Instrument [Line Items]
Maturity date	Aug. 15, 2026
Principal Outstanding	$ 2	$ 2
Interest rate	6.80%	6.80%
Unsecured Debt [Member] \| Senior Note Due 1/15/2027 [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 15, 2027
Principal Outstanding	$ 346	$ 346
Interest rate	7.875%	7.875%
Unsecured Debt [Member] \| Senior Note Due 8/15/2031 [Member]
Debt Instrument [Line Items]
Maturity date	Aug. 15, 2031
Principal Outstanding	$ 945	$ 945
Interest rate	9.00%	9.00%
Unsecured Debt [Member] \| Debentures Due 10/1/2034 [Member]
Debt Instrument [Line Items]
Maturity date	Oct. 1, 2034
Principal Outstanding	$ 1	$ 1
Interest rate	7.68%	7.68%
Unsecured Debt [Member] \| Debentures Due 7/1/2035 [Member]
Debt Instrument [Line Items]
Maturity date	Jul. 1, 2035
Principal Outstanding	$ 125	$ 125
Interest rate	7.45%	7.45%
Unsecured Debt [Member] \| Debentures Due 10/1/2046 [Member]
Debt Instrument [Line Items]
Maturity date	Oct. 1, 2046
Principal Outstanding	$ 193	$ 193
Interest rate	7.05%	7.05%
Secured Subsidiary Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 106	$ 106
Secured Subsidiary Debt [Member] \| Debentures Due 11/15/2031 [Member]
Debt Instrument [Line Items]
Maturity date	Nov. 15, 2031
Principal Outstanding	$ 100	$ 100
Interest rate	8.50%	8.50%
Secured Subsidiary Debt [Member] \| RUS Loan Contracts Due 1/3/2028 [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 3, 2028
Principal Outstanding	$ 6	$ 6
Interest rate	6.154%	6.154%
Unsecured Subsidiary Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 750	$ 750
Unsecured Subsidiary Debt [Member] \| Debentures due 5/15/2027 [Member]
Debt Instrument [Line Items]
Maturity date	May 15, 2027
Principal Outstanding	$ 200	$ 200
Interest rate	6.75%	6.75%
Unsecured Subsidiary Debt [Member] \| Debentures Due 2/1/2028 [Member]
Debt Instrument [Line Items]
Maturity date	Feb. 1, 2028
Principal Outstanding	$ 300	$ 300
Interest rate	6.86%	6.86%
Unsecured Subsidiary Debt [Member] \| Debentures Due 2/15/2028 [Member]
Debt Instrument [Line Items]
Maturity date	Feb. 15, 2028
Principal Outstanding	$ 200	$ 200
Interest rate	6.73%	6.73%
Unsecured Subsidiary Debt [Member] \| Debentures Due 10/15/2029 [Member]
Debt Instrument [Line Items]
Maturity date	Oct. 15, 2029
Principal Outstanding	$ 50	$ 50
Interest rate	8.40%	8.40%
Senior Secured Debt, Senior Unsecured Debt And Subsidiary Debentures [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 16,769	$ 17,516
Weighted average interest rate	8.188%	8.486%

Restructuring And Other Charg_3

Restructuring And Other Charges (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring And Other Charges [Abstract]
Restructuring reserve		$ 2	$ 15	$ 18
Payment of restructuring costs	$ 35
Restructuring charges		87	168	35
Transformation costs		8	46	23
Pension/OPEB special termination benefit enhancements			44
Severance costs		7	38	$ 12
Consulting and advisory costs		$ 72	$ 40

Restructuring And Other Charg_4

Restructuring And Other Charges (Changes In Restructuring Reserve) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring And Other Charges [Abstract]
Restructuring Reserve, Beginning Balance	$ 15	$ 18
Severance costs	7	38	$ 12
Transformation initiative costs	8	46	23
Other restructuring costs	72	40
Cash payments during the period	(100)	(127)
Restructuring Reserve, Ending Balance	$ 2	$ 15	$ 18

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Leases (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Line Items]
Option to terminate leases, Lessee	1 year
Increase of accumulated deficit	$ (8,975)	$ (8,573)
Option to terminate leases, Lessor	1 year
Lease revenue	$ 67	70	$ 73
Rental expense			102
Poles [Member]
Leases [Line Items]
Rental expense			$ 55
Accounting Standards Update 2016-02 [Member]
Leases [Line Items]
Deferred gain, Net		11
Increase of accumulated deficit		15
Accounting Standards Update 2018-11 [Member]
Leases [Line Items]
Increase of accumulated deficit		$ 15
Minimum [Member]
Leases [Line Items]
Operating and finance lease terms, Lessee	1 year
Operator lease terms, Lessor	1 year
Maximum [Member]
Leases [Line Items]
Operating and finance lease terms, Lessee	87 years
Operator lease terms, Lessor	65 years

Leases (Components Of Lease Cos

Leases (Components Of Lease Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Amortization of right-of-use assets	$ 15	$ 19
Interest on lease liabilities	13	15
Finance lease cost	28	34
Operating lease cost	68	79
Sublease income	(11)	(11)
Total Lease cost	85	102
Short-term lease cost	2	3
Variable lease cost	$ 6	$ 6

Leases (Supplemental Balance Sh

Leases (Supplemental Balance Sheet Information Related To Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Supplemental Balance Sheet Information Related To Leases [Line Items]
Operating right-of-use assets	$ 215	$ 204
Finance right-of-use assets	143	167
Operating lease liabilities	223	211
Finance lease liabilities	$ 145	$ 167
Operating leases, Weighted-average remaining lease term	7 years 9 months	7 years 6 months 14 days
Operating leases, Weighted-average discount rate	8.26%	8.25%
Finance lease, Weighted-average remaining lease term	8 years 11 months 15 days	9 years 1 month 6 days
Finance lease, Weighted-average discount rate	8.13%	7.98%
Other Current Liabilities [Member]
Supplemental Balance Sheet Information Related To Leases [Line Items]
Finance lease liabilities, Current	$ 21	$ 25
Current operating lease liabilities	48	44
Other Noncurrent Liabilities [Member]
Supplemental Balance Sheet Information Related To Leases [Line Items]
Financed lease liabilities, Noncurrent	124	142
Noncurrent operating lease liabilities	$ 175	$ 167

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	Dec. 31, 2018
Leases [Abstract]
Operating cash flows provided by operating leases	$ 67	$ 70
Operating cash flows used by operating leases	(68)	(76)
Operating cash flows used by finance leases	(13)	(15)
Financing cash flows used by finance leases	(23)	(35)	$ (36)
Right-of-use assets obtained in exchange for lease liabilities, Operating leases	28	42
Right-of-use assets obtained in exchange for lease liabilities, Finance leases	$ 3	$ 34

Leases (Maturity Analysis For O

Leases (Maturity Analysis For Operating and Finance Lease Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Present value of lease liabilities	$ 223	$ 211
Finance Lease, Liability, Payment, Due [Abstract]
Present value of lease liabilities	145	$ 167
Prior To Reclass To Assets Held-for-sale [Member]
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2021	49
2022	47
2023	42
2024	38
2025	32
Thereafter	87
Total lease payments	295
Less: imputed interest	(72)
Present value of lease liabilities	223
Finance Lease, Liability, Payment, Due [Abstract]
2021	32
2022	27
2023	23
2024	16
2025	14
Thereafter	82
Total lease payments	194
Less: imputed interest	(49)
Present value of lease liabilities	$ 145

Leases (Maturity Analysis For_2

Leases (Maturity Analysis For Operating Leases From Customers) (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 10
2022	10
2023	10
2024	7
2025	1
Thereafter	1
Total lease payments from customers	$ 39

Investment And Other Income (_3

Investment And Other Income (Loss), Net (Components Of Investment And Other Income (Loss), Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investment And Other Income (Loss), Net [Abstract]
Interest and dividend income	$ 4	$ 9	$ 6
Pension and OPEB benefit (costs)	(43)	(42)	10
All other, net	(4)	(4)	(3)
Total investment and other income (loss), net	$ (43)	$ (37)	$ 13

Capital Stock (Narrative) (Deta

Capital Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 02, 2018	Jun. 29, 2018	Jun. 24, 2015	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2015
Class of Stock [Line Items]
Common stock, Shares authorized					175,000,000	175,000,000
Common stock, Shares issued					106,025,000	106,025,000
Common stock, Shares outstanding					104,793,000	105,131,000
Class of stock conversion, rate		1.3333
Preferred dividends	$ 54			$ 107
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 1,866
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Shares issued					0	0
Preferred stock, Shares outstanding					0	0
Preferred Stock, Dividend Rate, Percentage				11.125%
Preferred Stock, Par or Stated Value Per Share				$ 0.01
Preferred stock, Shares authorized							19,250,000
Shares Issued, Price Per Share							$ 100
Common Stock [Member]
Class of Stock [Line Items]
Shares issued in stock conversion		25,529,000		25,529,000

Stock Plans (Narrative) (Detail

Stock Plans (Narrative) (Details) $ in Millions	12 Months Ended
Stock Plans (Narrative) (Details) $ in Millions	Dec. 31, 2020USD ($)itemShareBasedCompensationPlanshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plan under which grants were made \| ShareBasedCompensationPlan	4
Number of stock-based compensation plan under which grants were not made \| ShareBasedCompensationPlan	3
2013 EIP, Deferred Fee Plan and Directors’ Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under the plan (in shares)	0
2017 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under the plan (in shares)	3,632,000
Shares authorized for grant under the plans (in shares)	5,667,000
Plan authorization period	10 years
2013 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under the plan (in shares)	0
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Initial period over which target number of performance shares are awarded	90 days
Expense recognized during the period \| $	$ 0	$ 4	$ 5
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized during the period \| $	$ 2	11	13
Weighted average period over which unvested restricted stock awards unrecognized compensation cost is expected to be recognized (in years)	1 year
Stock Options [Member] \| 2017 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Non-Employee Directors’ Compensation Plan [Member] \| 2017 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under the plan (in shares)	0
Director Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized during the period \| $		$ 1	$ (1)
Number of directors participating in the plan during the period \| item	8
Plan units earned during the period (in shares)	0	155,045	183,791
Cash compensation \| $	$ 5	$ 4	$ 1
Maximum [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining unrecognized compensation cost associated with unvested restricted stock awards \| $	$ 1

Stock Plans (LTIP Target Perfor

Stock Plans (LTIP Target Performance Shares) (Details) - Performance Shares [Member] - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of period (in shares)	96	497	306
LTIP target performance shares granted			284
LTIP target performance shares earned		(381)	(18)
LTIP target performance shares forfeited	(96)	(20)	(75)
Balance at end of period (in shares)		96	497

Stock Plans (Restricted Shares

Stock Plans (Restricted Shares Outstanding) (Details) - Restricted Stock [Member] - USD ($) $ / shares in Units, shares in Thousands, $ 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]
Balance at beginning of period (in shares)	900	1,858	633
Restricted stock granted (in shares)		105	2,023
Restricted stock vested (in shares)	(387)	(1,039)	(221)
Restricted stock forfeited (in shares)	(209)	(24)	(577)
Balance at end of period (in shares)	304	900	1,858
Balance at beginning of period (in dollars per shares)	$ 10.57	$ 16.02	$ 58.63
Restricted stock granted (in dollars per shares)	0	2	8.26
Restricted stock vested (in dollars per shares)	15.04	19.05	66.82
Restricted stock forfeited (in dollars per shares)	7.79	28.30	16.47
Balance at end of period (in dollars per shares)	$ 6.78	$ 10.57	$ 16.02
Balance at beginning of period	$ 1	$ 4	$ 4
Restricted stock granted			5
Restricted stock vested		(1)	(1)
Balance at end of period		$ 1	$ 4

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Federal rate	21.00%	21.00%	21.00%
Expected income refunds	$ 13
Tax impact related to goodwill impairment		$ 524	$ 72
Income taxes paid	8	4	$ 4
Valuation allowance	783	$ 605
Gross tax liability for tax positions that may not be sustained under a more likely than not threshold	16
Effect of expiration of statute of limitations during next twelve months	$ 2
Deferred income tax payment period	2 years
Deferred income tax payment	$ 60
Percentage of limitation on use	80.00%
Shareholder's Right Plan [Member]
Income Tax Contingency [Line Items]
Beneficial ownership	4.90%
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	$ 1,800
Tax credit expiration year	2036
Research and development credits	$ 12
Internal Revenue Service (IRS) [Member] \| Indefinite Tax Period [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	121
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	$ 9,400
Tax credit expiration year	2039
Various tax credits	$ 34
Minimum [Member] \| Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year	2034
Minimum [Member] \| State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year	2020
Maximum [Member] \| Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year	2039
Maximum [Member] \| State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year	2023
Northwest Operations [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	$ 857

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Provision For Income Taxes) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Consolidated tax provision at federal statutory rate	21.00%	21.00%	21.00%
State income tax provisions, net of federal income tax benefit	21.70%	2.60%	1.60%
Tax reserve adjustment	(0.70%)		0.10%
Changes in certain deferred tax balances	(35.80%)	(2.30%)	(3.50%)
Interest expense deduction	30.70%
Restructuring cost	(10.00%)
Goodwill impairment		(11.80%)	(10.40%)
Loss on disposal of Northwest Operations	(9.10%)
Share-based payments	(0.20%)	(0.10%)	(0.50%)
Federal research and development credit	(0.50%)		0.10%
Deferred Tax Remeasurement - 2017 Tax Reform			0.60%
All other, net	0.10%		(0.20%)
Effective tax rate	17.20%	9.40%	8.80%

Income Taxes (Components Of Net

Income Taxes (Components Of Net Deferred Income Tax Liability (Asset) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax liabilities [Abstract]
Property, plant and equipment basis differences	$ 1,873	$ 2,184
Deferred revenue/expense	44	65
Other, net	56	56
Gross deferred income tax liability	1,973	2,305
Deferred income tax assets [Abstract]
Pension liability	308	256
Intangibles	681	665
Tax operating loss carryforward	923	898
Employee benefits	207	184
Interest expense deduction limitation carryforward	44	238
Accrued expenses	75	37
Lease obligations	83	92
Tax credit	40	39
Allowance for doubtful accounts	35	32
Other, net	17	7
Gross deferred income tax asset	2,413	2,448
Less: Valuation allowance	(783)	(605)
Net deferred income tax asset	1,630	1,843
Net deferred income tax liability	$ 343	$ 462

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current [Abstract]
Federal	$ (12)	$ 1	$ (1)
State	19	7	6
Total Current	7	8	5
Deferred [Abstract]
Federal	(84)	(606)	(77)
State	(7)	(13)	10
Total Deferred	(91)	(619)	(67)
Total income tax benefit	(84)	(611)	(62)
Income taxes charged (credited) to equity of Frontier [Abstract]
Deferred income taxes (benefits) arising from the recognition of additional pension/OPEB liability	35	32	(31)
Total income taxes charged (credited) to equity of Frontier	35	32	(31)
Total income tax benefit	$ (49)	$ (579)	$ (93)

Income Taxes (Changes In The Ba

Income Taxes (Changes In The Balance Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Abstract]
Unrecognized tax benefits - beginning of year	$ 12	$ 11
Gross increases - prior year tax positions	4
Gross increases - current year tax positions		1
Unrecognized tax benefits - end of year	$ 16	$ 12

Net Loss Per Common Share (Narr

Net Loss Per Common Share (Narrative) (Details) - shares	12 Months Ended
Net Loss Per Common Share (Narrative) (Details) - shares	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)	0	1,334	1,334
Non-Employee Directors' Deferred Fee Plan and Equity Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)	339,544	339,544	348,093

Net Loss Per Common Share (Calc

Net Loss Per Common Share (Calculation Of Net Loss Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Loss Per Common Share [Abstract]
Net loss attributable to Frontier common shareholders	$ (50)	$ 15	$ (181)	$ (186)	$ (162)	$ (345)	$ (5,317)	$ (87)	$ (402)	$ (5,911)	$ (750)
Total basic net loss attributable to Frontier common shareholders									(402)	(5,911)	(750)
Total diluted net loss attributable to Frontier common shareholders									$ (402)	$ (5,911)	$ (750)
Total weighted average shares and unvested restricted stock awards outstanding - basic (in shares)									104,944	105,356	91,523
Less: Weighted average unvested restricted stock awards									(477)	(1,291)	(1,840)
Total weighted average shares outstanding - basic									104,467	104,065	89,683
Basic net loss per share attributable to Frontier common shareholders									$ (3.85)	$ (56.80)	$ (8.37)
Total weighted average shares outstanding - diluted									104,467	104,065	89,683
Diluted net loss per share attributable to Frontier common shareholders									$ (3.85)	$ (56.80)	$ (8.37)

Comprehensive Loss (Narrative)

Comprehensive Loss (Narrative) (Details) - Pension Settlement Cost [Member] - Pension Benefits [Member] - Reclassification out of Accumulated Other Comprehensive Income [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications, pretax	$ (159)	$ (57)	$ (41)
Reclassifications, net of tax	$ 122	$ 43	$ 31

Comprehensive Loss (Accumulated

Comprehensive Loss (Accumulated Other Comprehensive Income (Loss), Net Of Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ (4,394)	$ 1,600	$ 2,274
Net current-period other comprehensive income (loss)	(105)	(108)	(97)
Balance	(4,900)	(4,394)	1,600
Deferred Taxes On Pension And OPEB Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Deferred tax items	234	204	250	$ 223
Defined Benefit Plans [Member] \| Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(684)	(489)	(345)
Other comprehensive income (loss) before reclassifications	(320)	(201)	(191)
Amounts reclassified from accumulated other comprehensive income (loss)	305	89	47
Net current-period other comprehensive income (loss)	(15)	(112)	(144)
Balance	(699)	(684)	(489)
Defined Benefit Plans [Member] \| Pension Benefits [Member] \| Accounting Standards Update 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(83)
Balance		(83)
Defined Benefit Plans [Member] \| Postretirement Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	34	26	(21)
Other comprehensive income (loss) before reclassifications	(76)	17	51
Amounts reclassified from accumulated other comprehensive income (loss)	(14)	(13)	(4)
Net current-period other comprehensive income (loss)	(90)	4	47
Balance	(56)	34	26
Defined Benefit Plans [Member] \| Postretirement Costs [Member] \| Accounting Standards Update 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	4
Balance		4
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(650)	(463)	(366)
Other comprehensive income (loss) before reclassifications	(396)	(184)	(140)
Amounts reclassified from accumulated other comprehensive income (loss)	291	76	43
Net current-period other comprehensive income (loss)	(105)	(108)	(97)
Balance	(755)	(650)	$ (463)
Accumulated Other Comprehensive Loss [Member] \| Accounting Standards Update 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ (79)
Balance		$ (79)

Comprehensive Loss (Reclassific

Comprehensive Loss (Reclassification Out Of AOCI) (Details) - Reclassification out of Accumulated Other Comprehensive Income [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member] \| Amortization Of Defined Benefit Cost Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	$ (339)	$ (115)	$ (65)
Tax impact	34	26	18
Reclassifications, net of tax	(305)	(89)	(47)
Pension Benefits [Member] \| Actuarial Gains (Losses) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	(99)	(58)	(24)
Pension Benefits [Member] \| Loss On Disposal [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	(81)
Pension Benefits [Member] \| Pension Settlement Cost [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	(159)	(57)	(41)
Reclassifications, net of tax	122	43	31
Postretirement Costs [Member] \| Amortization Of Defined Benefit Cost Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	19	15	6
Tax impact	(5)	(2)	(2)
Reclassifications, net of tax	14	13	4
Postretirement Costs [Member] \| Prior-Service Credits (Costs) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	32	11	9
Postretirement Costs [Member] \| Actuarial Gains (Losses) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	(6)	$ 4	$ (3)
Postretirement Costs [Member] \| Loss On Disposal [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	$ (7)

Segment Information (Narrative)

Segment Information (Narrative) (Details)	12 Months Ended
Segment Information (Narrative) (Details)	Dec. 31, 2020segment
Segment Information [Abstract]
Number of operating regions	1
Number of reportable segments	1

Quarterly Financial Data (Sched

Quarterly Financial Data (Schedule Of Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Revenue	$ 1,695	$ 1,726	$ 1,801	$ 1,933	$ 1,942	$ 1,997	$ 2,067	$ 2,101	$ 7,155	$ 8,107	$ 8,611
Operating income	277	270	140	272	221	26	(5,459)	339	959	(4,873)	827
Net earnings (loss) attributable to Frontier common shareholders	$ (50)	$ 15	$ (181)	$ (186)	$ (162)	$ (345)	$ (5,317)	$ (87)	$ (402)	$ (5,911)	$ (750)
Basic and diluted net earnings (loss) per share attributable to Frontier common shareholders	$ (0.48)	$ 0.14	$ (1.73)	$ (1.78)	$ (1.55)	$ (3.31)	$ (51.07)	$ (0.84)	$ (3.85)	$ (56.80)	$ (8.37)
Reorganization items, net									$ 409
Reorganization items, net of tax									361
Goodwill impairment										5,725	$ 641
Goodwill impairment, After-tax										5,201
Loss on disposal of Northwest Operations									162	446
Loss on disposal of Northwest Operations, After-tax									$ 118	$ 446

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Capitalization of pension and OPEB expense related to engineering and plant construction		$ 25	$ 24	$ 26
Contribution of Property				37
Contributions to plans	$ 27
Decrease in plan assets		$ (223)
Percentage of increase in pension plan		8.00%
Accumulated benefit obligation	3,640	$ 3,640	3,646
Remaining required plan contributions for fiscal year	120	120			$ 147
401(k) savings plan employer contributions		39	44	$ 45
Plan assets	2,507	2,507	2,730
Benefit payments		538
Special termination benefits			$ 44
Required plan contributions for plan year	$ 173	$ 173
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate - used at year end to value obligation (in hundredths)	2.60%	2.60%	3.40%	4.30%
Expected long-term rate of return on plan assets (in hundredths)		7.50%	7.50%	7.50%
Expected Long Term Rate Of Return On Plan Assets In Future Year In Hundredths		7.50%
Defined Benefit Plan, Settlements, Benefit Obligation		$ 465	$ 235
Defined Benefit Plan, Settlements Benefit obligation threshold		211
Pension settlement costs		159	57	$ 41
Remeasurement charges of other comprehensive income (loss)		16	145
Contribution of Property				37
Contributions to plans		$ 64	166
Employer cash contributions				113
Defined Benefit Plan, Funded Percentage	68.00%	68.00%
Actuarial (gain) loss		$ 506	603
Plan contributions required for fiscal year			166	150	$ 180
Plan assets	$ 2,507	2,507	2,730	$ 2,348
Benefit payments		73	65
Investment returns		(321)	(516)
Special termination benefits			38
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Remeasurement charges of other comprehensive income (loss)		119	(4)
Contributions to plans		52	40
Increase (decrease) in accumulated benefit obligation for plan amendment			149
Actuarial (gain) loss		$ 100	129
Annual rate of increase in the per-capita cost of covered medical benefits (in hundredths)	7.00%	7.00%
Annual rate of increase in the per-capita cost of covered medical benefits in 2029 (in hundredths)	5.00%	5.00%
Benefit payments		$ 61	47
Special termination benefits			$ 6
Postretirement Benefits Other Than Pensions (OPEB) [Member] \| Minimum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate - used at year end to value obligation (in hundredths)	2.60%	2.60%	3.40%	4.30%
Postretirement Benefits Other Than Pensions (OPEB) [Member] \| Maximum [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate - used at year end to value obligation (in hundredths)	2.80%	2.80%	3.50%	4.40%
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation	40.00%	40.00%
Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation	60.00%	60.00%
Management Expenses And Other Expenses [Member] \| Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investments in pension plan assets	$ 321	$ 321
Northwest Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Settlements, Benefit Obligation		159
Remeasurement charges of other comprehensive income (loss)		506
Northwest Operations [Member] \| Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investment returns		$ (70)

Retirement Plans (Projected Ben

Retirement Plans (Projected Benefit Obligation, Fair Values Of Plan Assets And Amounts Recognized In The Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in projected benefit obligation (PBO) [Roll Forward]
Benefits paid		$ (538)
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year		2,730
Employer contribution	$ 27
Fair value of plan assets at end of year	2,507	2,507	$ 2,730
Amounts recognized in the consolidated balance sheet [Abstract]
Pension and other postretirement benefits - current	(48)	(48)	(43)
Pension and other postretirement benefits - noncurrent	(2,195)	(2,195)	(1,896)
Elimination of future compensation increases		20
Pension Benefits [Member]
Change in projected benefit obligation (PBO) [Roll Forward]
PBO at beginning of year		3,726	3,173
Service cost		95	82	$ 90
Interest cost		108	130	125
Actuarial (gain) loss		506	603
Benefits paid		(73)	(65)
Impact of Divestiture of Northwest Operations		(189)
Settlements		(465)	(235)
Special termination benefits			38
PBO at end of year	3,708	3,708	3,726	3,173
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year		2,730	2,348
Fair value of plan assets for the Northwest Operations		(70)
Actual return on plan assets		321	516
Employer contribution		64	166
Settlements		(465)	(235)
Benefits paid		(73)	(65)
Fair value of plan assets at end of year	2,507	2,507	2,730	2,348
Funded status	(1,201)	(1,201)	(996)
Amounts recognized in the consolidated balance sheet [Abstract]
Pension and other postretirement benefits - noncurrent	(1,201)	(1,201)	(996)
Accumulated other comprehensive (gain) loss	915	915	899	754
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Change in projected benefit obligation (PBO) [Roll Forward]
PBO at beginning of year		972	965
Service cost		20	20	21
Interest cost		33	41	38
Plan amendments			(149)
Plan participants' contributions		9	7
Actuarial (gain) loss		100	129
Benefits paid		(61)	(47)
Impact of Divestiture of Northwest Operations		(31)
Special termination benefits			6
PBO at end of year	1,042	1,042	972	965
Change in plan assets [Roll Forward]
Plan participants' contributions		9	7
Employer contribution		52	40
Benefits paid		(61)	(47)
Funded status	(1,042)	(1,042)	(972)
Amounts recognized in the consolidated balance sheet [Abstract]
Pension and other postretirement benefits - current	(48)	(48)	(43)
Pension and other postretirement benefits - noncurrent	(994)	(994)	(900)
Pension and other postretirement benefits - AHFS			(29)
Accumulated other comprehensive (gain) loss	$ 74	$ 74	$ (45)	$ (41)

Retirement Plans (Net Periodic

Retirement Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Special termination benefits		$ 44
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 95	82	$ 90
Interest cost on projected benefit obligation	108	130	125
Expected return on plan assets	(171)	(172)	(192)
Amortization of unrecognized (gain) loss	99	58	24
Net periodic benefit cost	131	98	47
Pension settlement costs	159	57	41
Special termination benefits		38
Gain on disposal, net	(38)
Total benefit cost	252	193	88
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	20	20	21
Interest cost on projected benefit obligation	33	41	38
Amortization of prior service credit	(32)	(11)	(9)
Amortization of unrecognized (gain) loss	6	(4)	3
Net periodic benefit cost	27	46	53
Special termination benefits		6
Gain on disposal, net	(24)
Total benefit cost	$ 3	$ 52	$ 53

Retirement Plans (Weighted Aver

Retirement Plans (Weighted Average Asset Allocations, By Asset Category) (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundredths)	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundredths)	49.00%	49.00%
Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundredths)	37.00%	39.00%
Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundredths)	14.00%	12.00%

Retirement Plans (Expected Bene

Retirement Plans (Expected Benefit Payments Over The Next Ten Years) (Details) - Pension Benefits [Member] $ in Millions	Dec. 31, 2020USD ($)
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2021	$ 255
2022	252
2023	253
2024	256
2025	257
2026 - 2030	1,239
Total	$ 2,512

Retirement Plans (Schedule Of A

Retirement Plans (Schedule Of Assumptions Used) (Details)	12 Months Ended
Retirement Plans (Schedule Of Assumptions Used) (Details)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at year end to value obligation (in hundredths)	2.60%	3.40%	4.30%
Discount rate - used at beginning of year to compute annual cost (in hundredths)	3.40%	4.30%	3.70%
Expected long-term rate of return on plan assets (in hundredths)	7.50%	7.50%	7.50%
Rate of increase in compensation levels (in hundredths)	2.00%	2.00%	2.00%
Postretirement Benefits Other Than Pensions (OPEB) [Member] \| Maximum [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at year end to value obligation (in hundredths)	2.80%	3.50%	4.40%
Discount rate - used at beginning of year to compute annual cost (in hundredths)	3.50%	4.40%	3.80%
Postretirement Benefits Other Than Pensions (OPEB) [Member] \| Minimum [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at year end to value obligation (in hundredths)	2.60%	3.40%	4.30%
Discount rate - used at beginning of year to compute annual cost (in hundredths)	3.40%	4.30%	3.70%

Retirement Plans (Schedule Of E

Retirement Plans (Schedule Of Expected Benefit Payments For OPEB) (Details) $ in Millions	Dec. 31, 2020USD ($)
OPEB, Gross Benefits [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2021	$ 49
2022	48
2023	48
2024	52
2025	48
2026 - 2030	278
Total	523
Medicare Part D Subsidy [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2026 - 2030	2
Total	2
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2021	49
2022	48
2023	48
2024	52
2025	48
2026 - 2030	280
Total	$ 525

Retirement Plans (Net Periodi_2

Retirement Plans (Net Periodic Benefit Cost Not Yet Recognized) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member]
Defined Benefit Plan [Abstract]
Net actuarial loss	$ 915	$ 899
Total	915	899	$ 754
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plan [Abstract]
Net actuarial loss	192	105
Prior service credit	(118)	(150)
Total	$ 74	$ (45)	$ (41)

Retirement Plans (Amounts Recog

Retirement Plans (Amounts Recognized As A Component Of AOCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Accumulated other comprehensive (gain) loss at beginning of year	$ 899	$ 754
Net actuarial (gain) loss amortized during year	(99)	(58)
Net loss on disposal recognized during the year	(81)
Net actuarial loss occurring during year	355	260
Settlement loss recognized	(159)	(57)
Net amount recognized in comprehensive (loss) for the year	16	145
Accumulated other comprehensive (gain) loss at end of year	915	899
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Accumulated other comprehensive (gain) loss at beginning of year	(45)	(41)
Net actuarial (gain) loss amortized during year	(6)	4
Net loss on disposal recognized during the year	(7)
Prior service credit amortized during year	32	11
Prior service credit occurring during year		(149)
Net actuarial loss occurring during year	100	130
Net amount recognized in comprehensive (loss) for the year	119	(4)
Accumulated other comprehensive (gain) loss at end of year	$ 74	$ (45)

Fair Value Of Financial Instr_3

Fair Value Of Financial Instruments (Narrative) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value Of Financial Instruments [Abstract]
Reclassifications of investments between Level 1, 2, or 3	$ 0	$ 0
Liabilities Subject To Compromise Debt	$ 10,949,000,000

Fair Value Of Financial Instr_4

Fair Value Of Financial Instruments (Pension Plan Assets Measured At Fair Value On Recurring Basis) (Details) - Pension Benefits [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	$ 1,428	$ 1,501
Common/Collective Trusts	1,073	1,177
Interest in Registered Investment Companies	32	87
Interest and Dividend Receivable	5	6
Due from Broker for Securities Sold	22	61
Receivable Associated with Insurance Contract	7	7
Due to Broker for Securities Purchased	(60)	(109)
Total Plan Assets, at Fair Value	2,507	2,730
Cash and Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	55	46
U.S. Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	48	39
Corporate and Other Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	506	547
Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	510	552
Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	3	4
Interest in Registered Investment Companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	140	150
Interest in Limited Partnerships and Limited Liability Corporations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	166	163
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	708	752
Fair Value, Inputs, Level 1 [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	55	46
Fair Value, Inputs, Level 1 [Member] \| Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	510	552
Fair Value, Inputs, Level 1 [Member] \| Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	3	4
Fair Value, Inputs, Level 1 [Member] \| Interest in Registered Investment Companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	140	150
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	554	586
Fair Value, Inputs, Level 2 [Member] \| U.S. Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	48	39
Fair Value, Inputs, Level 2 [Member] \| Corporate and Other Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	506	547
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	166	163
Fair Value, Inputs, Level 3 [Member] \| Interest in Limited Partnerships and Limited Liability Corporations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	166	163
Fair Value Measured at Net Asset Value Per Share [Member] \| Interest in Registered Investment Companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments at fair value	$ 32	$ 87

Fair Value Of Financial Instr_5

Fair Value Of Financial Instruments (Changes In Fair Value Of Plan's Level 3 Assets) (Details) - Interest in Limited Partnerships and Limited Liability Corporations [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance, beginning of year	$ 163	$ 155
Realized gains	14	14
Unrealized gains	3	8
Sales and distributions	(14)	(14)
Balance, end of year	$ 166	$ 163

Fair Value Of Financial Instr_6

Fair Value Of Financial Instruments (Redemption Of The Plan's Level 3 Investments) (Details) - Interest in Limited Partnerships and Limited Liability Corporations [Member] $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 166	$ 163	$ 155
MS IFHF SVP LP Cayman [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1
Liquidation Period (in years)	4 years
RII World Timberfund, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 5
Liquidation Period (in years)	2 years
E. Casino Road, LLC (Member)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 17
E. Casino Road, LLC (Member) \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	7
Comm Drive, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 10
Comm Drive, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	7.75
CTE Drive, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 11
CTE Drive, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	9.50
Oakbrook Parkway LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 27
Oakbrook Parkway LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	7.75
West Jefferson, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 29
West Jefferson, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	8.75
MacCorkle Ave SE, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 15
MacCorkle Ave SE, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	8.75
S. Pike Road West, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1
S. Pike Road West, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	8.50
N. US 131, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1
N. US 131, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	9.50
E. Stockton Blvd, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 7
E. Stockton Blvd, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	7.25
E. Lime Street, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 9
E. Lime Street, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	9
N. Morgan Street, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 33
N. Morgan Street, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	8.50
Minimum [Member] \| CTE Drive, LLC [Member] \| Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization Rate	9.50

Fair Value Of Financial Instr_7

Fair Value Of Financial Instruments (Fair Value Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Carrying Amount [Member]
Long-term debt [Abstract]
Total debt	$ 16,769	$ 17,516
Fair Value [Member]
Long-term debt [Abstract]
Total debt	$ 11,635	$ 12,026

Commitments And Contingencies_2

Commitments And Contingencies (Narrative) (Details) $ in Millions	Dec. 07, 2020USD ($)itemshares	May 01, 2020USD ($)itemstate	Jan. 30, 2020USD ($)	Dec. 31, 2015USD ($)itemstate	Dec. 31, 2020state
Commitments And Contingencies [Line Items]
Number of states of operation \| state					25
CAF Phase II [Member]
Commitments And Contingencies [Line Items]
Number of states of operation \| state				29	25
Annual support offered by the Federal Communications Commission				$ 332
Number of location broadband available \| item				774,000
CAF Phase II [Member] \| Northwest Operations [Member]
Commitments And Contingencies [Line Items]
Annual support offered by the Federal Communications Commission		$ 19
Number of location broadband available \| item		41,000
Number of states of the Northwest operations \| state		4
RDOF Program, Phase I [Member]
Commitments And Contingencies [Line Items]
Award amount	$ 371
Period to build gigabit capable broadband	10 years
Number of location to build gigabit capable broadband \| item	127,000
Number of states to build gigabit capable broadband \| shares	8
Minimum [Member]
Commitments And Contingencies [Line Items]
Terms of lease arrangements					1 year
Minimum [Member] \| RDOF Program, Phase II [Member]
Commitments And Contingencies [Line Items]
Annual support offered by the Federal Communications Commission			$ 11,200
Maximum [Member]
Commitments And Contingencies [Line Items]
Terms of lease arrangements					99 years

Commitments and Contingencies_3

Commitments and Contingencies (Future Payments For Obligations Under Noncancelable Long Distance Contracts And Service Agreements) (Details) $ in Millions	Dec. 31, 2020USD ($)
Commitments And Contingencies [Abstract]
2021	$ 85
2022	22
2023	19
2024	4
2025	2
Thereafter	4
Total	$ 136

Commitments and Contingencies_4

Commitments and Contingencies (Outstanding Performance Letters Of Credit) (Details) - Letter of Credit [Member] $ in Millions	Dec. 31, 2020USD ($)
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	$ 139
CNA Financial Corporation (CNA) [Member]
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	49
AIG Insurance [Member]
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	28
Zurich [Member]
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	$ 62