Frontier Communications Parent (FYBR) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Feb. 26, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	FRONTIER COMMUNICATIONS CORP
Entity Central Index Key	20,520
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 559,443
Entity Common Stock, Shares Outstanding		105,303,000
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Trading Symbol	ftr

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 354	$ 362
Accounts receivable, less allowances of $105 and $69, respectively	723	819
Contract acquisition costs	107
Prepaid expenses	86	78
Income taxes and other current assets	60	64
Total current assets	1,330	1,323
Property, plant and equipment, net	14,187	14,377
Goodwill, net	6,383	7,024
Other intangibles, net	1,494	2,063
Other assets	265	97
Total assets	23,659	24,884
Current liabilities:
Long-term debt due within one year	814	656
Accounts payable	495	564
Advanced billings	256	270
Accrued content costs	91	102
Accrued other taxes	182	156
Accrued interest	381	401
Pension and other postretirement benefits	39	29
Other current liabilities	303	330
Total current liabilities	2,561	2,508
Deferred income taxes	1,109	1,139
Pension and other postretirement benefits	1,750	1,676
Other liabilities	281	317
Long-term debt	16,358	16,970
Equity:
Preferred stock, $0.01 par value (50,000 authorized shares, 11.125%, Series A, 0 and 19,250 shares issued and outstanding at December 31, 2018 and 2017, respectively)
Common stock, $0.25 par value (175,000 authorized shares, 106,025 and 79,532 issued, and 105,536 and 78,441 outstanding, at December 31, 2018 and 2017, respectively)	27	20
Additional paid-in capital	4,802	5,034
Accumulated deficit	(2,752)	(2,263)
Accumulated other comprehensive loss, net of tax	(463)	(366)
Treasury common stock	(14)	(151)
Total equity	1,600	2,274
Total liabilities and equity	$ 23,659	$ 24,884

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Allowances for accounts receivable, current	$ 105	$ 69
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)	105,536,000	78,441,000
Common stock, shares issued (in shares)	106,025,000	79,352,000
Series A Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	50,000,000	50,000,000
Preferred Stock, Dividend Rate, Percentage	11.125%	11.125%
Preferred Stock, Shares Issued	0	19,250,000
Preferred Stock, Shares Outstanding	0	19,250,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements Of Operations [Abstract]
Revenue	$ 8,611	$ 9,128	$ 8,896
Operating expenses:
Network access expenses	1,441	1,597	1,470
Network related expenses	1,898	1,958	1,876
Selling, general and administrative expenses	1,815	2,017	2,081
Depreciation and amortization	1,954	2,184	2,031
Goodwill impairment	641	2,748
Acquisition and integration costs		25	436
Restructuring costs and other charges	35	82	91
Total operating expenses	7,784	10,611	7,985
Operating income (loss)	827	(1,483)	911
Investment and other income, net	13	1	4
Pension settlement costs	41	83
Gain (Loss) on early extinguishment of debt and debt exchanges	32	(88)	(7)
Interest expense	1,536	1,534	1,531
Loss before income taxes	(705)	(3,187)	(623)
Income tax benefit	(62)	(1,383)	(250)
Net loss	(643)	(1,804)	(373)
Less: Dividends on preferred stock	107	214	214
Net loss attributable to Frontier common shareholders	$ (750)	$ (2,018)	$ (587)
Basic and diluted net loss per share attributable to Frontier common shareholders	$ (8.37)	$ (25.99)	$ (7.61)
Total weighted average shares outstanding - Basic and diluted	89,683	77,736	77,607

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Loss - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements Of Comprehensive Loss [Abstract]
Net loss	$ (643)	$ (1,804)	$ (373)
Other comprehensive income (loss), net of tax	(97)	21	(34)
Comprehensive loss	$ (740)	$ (1,783)	$ (407)

Consolidated Statements Of Equi

Consolidated Statements Of Equity - USD ($) shares in Thousands, $ in Millions	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Common Stock [Member]	Total
Preferred Stock Balance (in shares) at Dec. 31, 2015	19,250
Balance, beginning at Dec. 31, 2015		$ 20	$ 6,312	$ (87)	$ (353)	$ (278)	$ 5,614
Balance (in shares) at Dec. 31, 2015		79,532				(1,652)
Stock plans			(44)			$ 63	19
Stock plans (in shares)						290
Dividends on common stock			(493)				(493)
Dividends on preferred stock			(214)				(214)
Net loss				(373)			(373)
Other comprehensive income (loss), net of tax					(34)		(34)
Preferred Stock Balance (in shares) at Dec. 31, 2016	19,250
Balance, ending at Dec. 31, 2016		$ 20	5,561	(460)	(387)	$ (215)	4,519
Balance (in shares) at Dec. 31, 2016		79,532				(1,362)
Cumulative-effect adjustment and impact of adoption in accounting principle				1			1
Stock plans			(47)			$ 64	17
Stock plans (in shares)						271
Dividends on common stock			(266)				(266)
Dividends on preferred stock			(214)				(214)
Net loss				(1,804)			(1,804)
Other comprehensive income (loss), net of tax					21		21
Preferred Stock Balance (in shares) at Dec. 31, 2017	19,250
Balance, ending at Dec. 31, 2017		$ 20	5,034	(2,263)	(366)	$ (151)	$ 2,274
Balance (in shares) at Dec. 31, 2017		79,532				(1,091)	78,441
Cumulative-effect adjustment and impact of adoption in accounting principle				154			$ 154
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			(107)				(107)
Net loss				(643)			(643)
Other comprehensive income (loss), net of tax					(97)		(97)
Balance, ending at Dec. 31, 2018		$ 27	$ 4,802	$ (2,752)	$ (463)	$ (14)	$ 1,600
Balance (in shares) at Dec. 31, 2018		106,025				(489)	105,536

Consolidated Statements Of Eq_2

Consolidated Statements Of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements Of Equity [Abstract]
Common stock, Cash dividends declared		$ 3.42	$ 6.35
Preferred stock, Cash dividends declared	$ 5.56	$ 11.12	$ 11.12

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows provided from (used by) operating activities:
Net loss	$ (643)	$ (1,804)	$ (373)
Adjustments to reconcile net loss to net cash provided from operating activities:
Depreciation and amortization	1,954	2,184	2,031
(Gain) Loss on early extinguishment of debt and debt exchanges	(32)	88	7
Pension settlement costs	41	83
Special termination benefits		5	26
Stock based compensation expense	18	14	24
Amortization of deferred financing costs	34	33	46
Other adjustments	(32)	(14)	(12)
Deferred income taxes	(67)	(1,385)	(206)
Goodwill impairment	641	2,748
Change in accounts receivable	65	122	(19)
Change in accounts payable and other liabilities	(141)	(298)	67
Change in prepaid expenses, income taxes and other assets	(26)	74	85
Net cash provided from operating activities	1,812	1,850	1,676
Cash flows provided from (used by) investing activities:
Cash paid for CTF acquisition			(9,871)
Capital expenditures - Business operations	(1,192)	(1,154)	(1,259)
Capital expenditures - Integration activities		(34)	(142)
Proceeds on sale of assets	11	110	8
Other	5	24	5
Net cash used by investing activities	(1,176)	(1,054)	(11,259)
Cash flows provided from (used by) financing activities:
Long-term debt payments	(2,515)	(1,811)	(453)
Proceeds from long-term debt borrowings	1,840	1,500	1,940
Proceeds from revolving debt	525
Repayment of revolving debt	(250)
Financing costs paid	(43)	(15)	(39)
Dividends paid on common stock		(266)	(493)
Dividends paid on preferred stock	(107)	(214)	(214)
Premium paid to retire debt	(17)	(86)
Capital lease obligation payments	(36)	(42)	(8)
Other	(5)	(8)	(8)
Net cash provided from (used by) financing activities	(608)	(942)	725
Increase (Decrease) in cash, cash equivalents and restricted cash	28	(146)	(8,858)
Cash, cash equivalents and restricted cash at January 1,	376	522	9,380
Cash, cash equivalents and restricted cash at December 31,	404	376	522
Cash paid (received) during the period for:
Interest	1,507	1,548	1,467
Income tax payments (refunds), net	4	(51)	(120)
Non-cash investing and financing activities:
Financing obligation for contributions of real property to pension plan	37		15
Reduction of pension obligation	$ 37		15
Increase (Decrease) in capital expenditures due to changes in accounts payable		50	(60)
Capital lease obligations		$ 17	$ 111

Description Of Business And Sum

Description Of Business And Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
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 the fourth largest Incumbent Local Exchange Carrier (ILEC) in the United States, with approximately 4.5 million customers, 3.7 million broadband subscribers and 21,200 employees, operating in 29 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.  Effective April 1, 2016, Frontier’s scope of operations and balance sheet changed materially as a result of the completion of the CTF Acquisition, as described in Note 4 - Acquisitions. Historical financial data presented for Frontier is not indicative of the future financial position or operating results for Frontier, and includes the results of the CTF Operations, as defined in Note 4 – Acquisitions, from the date of acquisition on April 1, 2016.  (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, 2018, 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.  On July 10, 2017, we effected a one for fifteen reverse stock split of our common stock. The reverse stock split reduced the number of common shares issued (which includes outstanding shares and treasury shares) from approximately 1,193,000,000 shares to 80,000,000 shares, and reduced shares outstanding from 1,178,000,000 shares to 79,000,000 shares. In addition, and at the same time, the total number of shares of common stock that Frontier is authorized to issue changed from 1,750,000,000 shares to 175,000,000 shares. There was no change in the par value of the common stock, and no fractional shares were issued. All share and per share amounts in the financial statements and footnotes have been retroactively adjusted for all periods presented to give effect to the reverse stock split. As a result of our reverse stock split the conversion rates of our Series A Preferred Stock were proportionately adjusted.  (c) Cash Equivalents : We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents. Restricted cash of $50 million is included within “Other assets” on our consolidated balance sheet as of December 31, 2018 and $14 million is included within “Income taxes and other current assets” on our consolidated balance sheet as of December 31, 2017. These amounts represent funds held as collateral by certain insurance carriers.  (d) Revenue Recognition : Revenue for Voice services, Data & Internet services, Video services, Switched and nonswitched access services will be recognized as the service is provided. 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. 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.  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 $213 million, $216 million, and $217 million for the years ended December 31, 2018, 2017, and 2016, respectively, and video franchise fees of $47 million, $52 million, and $37 million for the years ended December 31, 2018, 2017, and 2016, respectively, that we have recorded on a gross basis in our consolidated statements of operations and included within “Revenue” and “Network related expenses.  In 2015, we accepted the FCC’s Connect America Fund (CAF) Phase II offer of support, which is a successor to and augments the USF frozen high cost support that we had been receiving pursuant to a 2011 FCC order. Upon completion of the 2016 acquisition of properties in California, Texas, and Florida with Verizon (CTF Acquisition), Frontier assumed the CAF Phase II support and related obligations that Verizon had previously accepted with regard to California and Texas. We are recognizing these subsidies into revenue on a straight-line basis.  For additional information about our revenue policies and other required disclosures in accordance with ASC 606, refer to Note 3.  (e) 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.  (f) Goodwill and Other Intangibles : Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible net assets acquired. We undertake studies to determine the fair values of assets and liabilities acquired and allocate purchase prices to assets and liabilities, including property, plant and equipment, goodwill and other identifiable intangibles. We examine the carrying value of our goodwill and trade name annually as of December 31, or more frequently, as circumstances warrant, to determine whether there are any impairment losses. We test for goodwill impairment at the “operating segment” level, as that term is defined in GAAP.  We determined that we have one operating segment based on a number of factors that our management uses to evaluate and run our business operations, including similarities of customers, products and technology. We tested goodwill for impairment as of December 31, 2018 as a result of the continued decline in share price of our common stock since September 30, 2018, the date of our last goodwill impairment test. Refer to Note 7 for a discussion of our goodwill impairment testing and results as of December 31, 2018. We adopted ASU No. 2017-04, “Simplifying the Test for Goodwill Impairment” during 2017 in conjunction with our goodwill impairment assessment.  Frontier amortizes finite-lived intangible assets over their estimated useful lives on the accelerated method of sum of the years digits. We review such intangible assets at least annually as of December 31 to assess whether any potential impairment exists and whether factors exist that would necessitate a change in useful life and a different amortization period.  (g) 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 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 tangible and intangible assets to determine whether any changes are required.  (h) 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.  (i) 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.  (j) 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 14 – Net Loss Per Common Share. 

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2018
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	(2) Recent Accounting Pronouncements :  Recently Adopted Accounting Pronouncements  Revenue Recognition In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, “ Revenue from Contracts with Customers .” This standard, along with its related amendments, requires companies to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which they expect to be entitled in exchange for those goods or services. Frontier adopted the standard during the first quarter of 2018, using the modified retrospective method – i.e., by recognizing the cumulative effect of initially applying Accounting Standards Codification Topic (ASC) 606 as an adjustment to the opening balance of shareholders’ equity at January 1, 2018. The comparative information for historical periods has not been adjusted and continues to be reported under ASC 605. See Note 3 for additional details and disclosures.  The table below summarizes the impact of the adoption of ASC 606 on revenue, operating expenses, and operating income for the year ended December 31, 2018:      For the year ended December 31, 2018  Amounts without  Adjustments Adoption of  ($ in millions) As Reported for ASC 606 ASC 606   Revenue $ 8,611 $ (15) $ 8,596  Operating expenses 7,784 15 7,799  Operating income $ 827 $ (30) $ 797   Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March 2017, the FASB issued ASU No. 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost”. This standard was established to improve the presentation of net periodic pension cost and net periodic postretirement benefit cost by requiring that an employer disaggregate the service cost component of periodic benefit cost from the other components of net benefit cost. The amendments in the update also provide explicit guidance on how to present the service cost component and other components of net benefit cost in the Statement of operations and allow only the service cost components of net benefit cost to be eligible for capitalization. Frontier retrospectively adopted the standard during the first quarter of 2018 and applied changes to our presentation of pension settlement costs and certain other benefit costs. Frontier utilized the practical expedient utilizing the amounts disclosed in its pension and other postretirement plan note (Note 18) for prior comparative periods as the estimation basis for applying retrospective presentation requirements.  The table below summarizes the impact of adoption of ASU No. 2017-07 for the years ended December 31, 2017 and 2016:      For the year ended December 31,  2017 2016  Impact of Impact of  Adoption of Adoption of  ($ in millions) As Reported ASU 2017-07 As Restated As Reported ASU 2017-07 As Restated  Operating expenses:  Network related expenses $ 1,959 $ (1) $ 1,958 $ 1,887 $ (11) $ 1,876  Selling, general and administrative expenses $ 2,018 $ (1) $ 2,017 $ 2,093 $ (12) $ 2,081  Pension settlement costs $ 83 $ (83) $ - $ - $ - $ -   Non-operating income/expenses:  Investment and other income, net $ 3 $ (2) $ 1 $ 27 $ (23) $ 4  Pension settlement costs $ - $ 83 $ 83 $ - $ - $ -    Recent Accounting Pronouncements Not Yet Adopted  Leases In February 2016, the FASB issued ASU No. 2016 – 02, “Leases (ASC 842).” This standard, along with its amendments, establishes the principles to report transparent and economically neutral information about the assets and liabilities that arise from leases. Upon implementation, lessees will need to recognize almost all leases on their balance sheet as a right-of-use asset and a lease liability. For income statement purposes, the FASB retained a dual model, requiring leases to be classified as either operating or finance. Lessor accounting is similar to the current model but updated to align with certain changes to the lessee model and the new revenue recognition standard. The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Frontier plans to adopt ASC 842 using the modified retrospective approach. Therefore, we will not adjust the balance sheet for comparative periods but will record a cumulative effect adjustment to accumulated deficit on January 1, 2019. For lessee and lessor agreements, the new standard provides a number of optional practical expedients in transition. Frontier expects to elect the ‘package of practical expedients’, which permits the Company to not reassess under the new standard it’s prior conclusions about lease identification, lease classification, and initial direct costs. Additionally, Frontier expects to elect the land easement practical expedient, which permits the Company to account for land easements under the new standard only on a prospective basis. Frontier does not expect to elect the us of hindsight practical expedient.  For lessee agreements, the standard also provides practical expedients for an entity’s ongoing accounting. Frontier expects to elect the short-term lease recognition exemption for all leases that qualify. This means, for leases with terms of less than twelve months, we will not recognize assets or liabilities, including existing leases at transition. Frontier does not expect to elect the practical expedient to not separate lease and non-lease components. On adoption, we expect to recognize additional operating liabilities with corresponding right of use assets based on the present values of the remaining minimum rental payments for existing operating leases. Additionally, we expect to recognize the deferred gain of approximately $16 million on certain failed leaseback transactions that would qualify for sale-leaseback accounting under the new guidance as a cumulative effect adjustment to accumulated deficit on January 1, 2019. A significant number of Frontier’s telecom service contracts include equipment rentals to its customers, The Company expects to apply the practical expedient to account for those associated equipment rentals and telecom services as a single, combined component. We have evaluated the service component to be ‘predominant’ in these contracts and will account for the combined component as a single performance obligation under ASC 606. Frontier expects substantially all of its lessor agreements to be classified as operating leases under the new standard.  We are implementing changes to our systems, processes, policies and internal controls to meet the standard’s reporting and disclosure requirements. The impact of adopting this standard will result in an increase to assets and liabilities that we expect is less than 3 % of our total assets and total liabilities. The impact to the consolidated statement of operations, comprehensive loss, equity and cash flows is expected to be immaterial.  Financial Instrument Credit Losses In June 2016, The FASB issued ASU 2016-13, “Financial Instruments – Credit Losses”, which amends 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, 2019, with early adoption permitted. Frontier is currently evaluating the impact of adoption of this standard on our consolidated financial statements.  Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, FASB issued ASU 2018-02, which allows for the reclassification of certain income tax effects related to the Tax Cuts and Jobs Act (the “Tax Act”) between “Accumulated other comprehensive income” and “Retained earnings.” This ASU relates to the requirement that adjustments to deferred tax liabilities and assets related to a change in tax laws or rates to be included in “Income from continuing operations,” even in situations where the related items were originally recognized in “Other comprehensive income” (rather than in “Income from continuing operations”). The amendments in this ASU are effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. Adoption of this ASU is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the tax laws or rates were recognized. Frontier plans to adopt the standard during the first quarter of 2019. Upon adoption, Frontier anticipates an increase to Retained earnings of approximately $80 million, with a corresponding decrease to Accumulated other comprehensive income on the consolidated balance sheet.  Improvements to Nonemployee Share-Based Payment Accounting In June 2018, the FASB issued Accounting Standards Update (“ASU”) No. 2018-07, “Compensation — Stock Compensation (ASC 718), Improvements to Nonemployee Share-Based Payment Accounting,” which aligns the measurement and classification guidance for share-based payments to nonemployees with that for employees, with certain exceptions. It expands the scope of ASC 718 to include share-based payments granted to nonemployees and supersedes the guidance in ASC 505-50. Currently, nonemployee share-based payment awards are measured at the fair value of the consideration received or the fair value of the equity instruments issued, whichever can be more reliably measured. The ASU retains the existing cost attribution guidance, which requires entities to recognize compensation cost for nonemployee awards in the same period and in the same manner (i.e., capitalize or expense) they would if they paid cash for the goods or services, but it moves the guidance to ASC 718. ASU 2018-07 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. Frontier expects a minimal impact to our financial statements from adoption of this standard.  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. Early adoption is permitted. Frontier is currently evaluating the impact of the adoption of this standard on our disclosures.  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. We are required to adopt this guidance beginning January 1, 2021. Early adoption is permitted. The amendments in the standard would need to be applied on a retrospective basis. Frontier is currently evaluating the impact of the adoption of this standard on our disclosures.

ASC 606 Adoption And Revenue Re

ASC 606 Adoption And Revenue Recognition	12 Months Ended
	Dec. 31, 2018
ASC 606 Adoption And Revenue Recognition [Abstract]
ASC 606 Adoption And Revenue Recognition	(3) ASC 606 Adoption and Revenue Recognition:  Frontier applied ASC 606 using the modified retrospective method – i.e., by recognizing the cumulative effect of initially applying ASC 606 as an adjustment to the opening balance of equity at January 1, 2018. The historical periods have not been adjusted and continue to be reported under ASC 605 “Revenue Recognition.”  The following table includes information for the transition adjustment recorded as of January 1, 2018 to record the cumulative impact of adoption of ASC 606 for prior periods.      As Reported ASC 606 Adjusted  ($ in millions) December 31, 2017 Transition Adjustment January 1, 2018  Assets  Accounts receivable, net $ 819 $ (32) $ 787  Contract acquisition costs $ - $ 87 $ 87  Other current assets $ 64 $ 4 $ 68  Property, plant and equipment, net $ 14,377 $ 15 $ 14,392  Other assets $ 97 $ 127 $ 224   Liabilities and Equity  Other current liabilities $ 330 $ 5 $ 335  Other liabilities $ 317 $ (9) $ 308  Deferred income taxes $ 1,139 $ 51 $ 1,190  Accumulated deficit $ (2,263) $ 154 $ (2,109)   The details of the significant changes are set out below.  Bundled Service and Allocation of Discounts When customers purchase more than one service, the revenue allocable to each service under ASC 606 is determined based upon the relative stand-alone selling price of each service received. While this change results in different allocations to each of the services, it does not change total customer revenue. 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 discount 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 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 under ASC 606. 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 expense”, 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. As part of the above transition adjustment, $40 million and $37 million of Short-term and Long-term contract assets were recorded, respectively. As of December 31, 2018, we have included $44 million of Short-term contract assets in Other current assets and $25 million of Long-term contract assets in 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 must be 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. As part of the transition adjustment above, $12 million and $9 million of Short-term and Long-term contract liabilities were recorded, respectively, for carrier upfront fees. As of December 31, 2018, we have included $12 million of Short-term contract liabilities in Other current liabilities and $9 million of Long-term contract liabilities in Other liabilities on our consolidated balance sheet related to carrier upfront fees.  Contract Acquisition Costs Under ASC 606, certain costs to acquire customers must be deferred and amortized over the related contract period or expected customer life (average of 3.8 years). For Frontier, this includes certain commissions paid to acquire new customers. Beginning January 1, 2018, commissions attributable to new customer contracts are being deferred and amortized into expense. Historically these acquisition costs were expensed as incurred. Frontier expects that the incremental commissions paid as a result of acquiring customers are recoverable and therefore, as part of the transition adjustment above, short-term acquisition costs of $87 million and long-term contract acquisition costs of $117 million were deferred. For the year ended December 31, 2018, Frontier deferred $138 million of costs and amortized deferred costs of $108 million to Selling, general and administrative expense. As of December 31, 2018, we have recorded short-term contract acquisition costs of $107 million and included $127 million of long-term contract acquisition costs in Other assets on our consolidated balance sheet.  Reserves and Disputes For carrier disputes, Frontier previously recorded a reserve as a reduction of commercial revenue on a case by case basis once the carrier claim was validated by Frontier. Under ASC 606, credits issued for disputes are variable consideration and an estimate for the credits to be issued is now being recorded at the time of customer billing and the related contract liability is reflected in our Allowance for doubtful accounts (see Note 5). During 2018, there were $12 million in additional reserves recorded under the requirements of ASC 606 that would not have been recorded under the requirements of ASC 605.  Switched Access Under ASC 606, switched access revenue, which has been historically reflected in Other regulatory revenue, is considered revenue from a customer; therefore, will be reflected in commercial customer revenue on a prospective basis.  Contributions in Aid of Construction (CIAC) It is customary for us to charge customers for certain construction activities requested by them. Historically, these amounts were reflected as offsets to the costs of construction and were recorded net in property, plant and equipment accounts. Under ASC 606, certain CIAC amounts will now be recognized as other customer revenue. For the year ended December 31, 2018, we recognized $41 million in Revenue for performance obligations that were satisfied during the period.  USF Fees Universal Service Fund Fees assessed to our customers were previously reflected in regulatory revenue. Under ASC 606, these amounts are being included in contract value and allocated to the services which have been delivered based on relative stand-alone selling price of each service.  The following table summarizes the impacts of adopting ASC 606 on Frontier’s consolidated balance sheet as of December 31, 2018.     December 31, 2018  Impact of Amounts Excluding  ($ in millions) As Reported Adoption of ASC 606 Adoption of ASC 606  Assets  Accounts receivable, net $ 723 $ 44 $ 767  Contract acquisition costs $ 107 $ (107) $ -  Prepaid expenses $ 86 $ 3 $ 89  Other current assets $ 60 $ (4) $ 56  Property, plant and equipment, net $ 14,187 $ (56) $ 14,131  Other assets $ 265 $ (117) $ 148   Liabilities and Equity  Other current liabilities $ 303 $ (6) $ 297  Other liabilities $ 281 $ 10 $ 291  Deferred income taxes $ 1,109 $ (57) $ 1,052  Accumulated deficit $ (2,752) $ (184) $ (2,936)   The following tables summarize the impacts of adopting ASC 606 on Frontier’s statement of operations for the year ended December 31, 2018.     For the year ended December 31, 2018  Impact of Amounts Excluding  As Reported Adoption of ASC 606 Adoption of ASC 606  ($ in millions)  Revenue $ 8,611 $ (15) $ 8,596   Operating expenses:  Network access expenses 1,441 (3) 1,438  Network related expenses 1,898 - 1,898  Selling, general and administrative expenses 1,815 19 1,834  Other operating expenses 2,630 (1) 2,629  Total operating expenses 7,784 15 7,799   Operating income (loss) $ 827 $ (30) $ 797   The impact of adoption of ASC 606 on net loss, basic and diluted net loss per share, consolidated statement of comprehensive loss, and the consolidated statement of cash flows were not material for the year ended December 31, 2018.  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 through the FiOS® and Vantage video brands, 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. Because of limited comparability for historical periods, we have reflected the current period under both an ASC 606 basis as well as the historical ASC 605 basis.     For the year ended December 31,  2018  Amounts  Impact of Excluding  Adoption of Adoption of  ($ in millions) As Reported ASC 606 ASC 606 2017 2016  Data and Internet services $ 3,878 $ (103) $ 3,775 $ 3,862 (1) $ 3,693 (1)  Voice services 2,721 (152) 2,569 2,864 2,886  Video services 1,085 99 1,184 1,304 1,244  Other 544 (193) 351 322 276  Revenue from contracts  with customers 8,228 (349) 7,879 8,352 (1) 8,099 (1)  Subsidy and other regulatory revenue 383 334 717 776 797  Total revenue $ 8,611 $ (15) $ 8,596 $ 9,128 (1) $ 8,896 (1)   For the year ended December 31,  2018  Amounts  Impact of Excluding  Adoption of Adoption of  ($ in millions) As Reported ASC 606 ASC 606 2017 2016  Consumer $ 4,380 $ (116) $ 4,264 $ 4,476 $ 4,383  Commercial 3,848 (233) 3,615 3,876 (1) 3,716 (1)  Revenue from contracts  with customers 8,228 (349) 7,879 8,352 (1) 8,099 (1)  Subsidy and other regulatory revenue 383 334 717 776 797  Total revenue $ 8,611 $ (15) $ 8,596 $ 9,128 (1) $ 8,896 (1)   (1) Includes revenue from Frontier Secure Strategic Partnerships business, which was sold in May of 2017, of $40 million and $84 million for the years ended December 31, 2017 and 2016, respectively.  Frontier satisfies its obligations to customers by transferring goods and services in exchange for consideration received from the customer. The timing of Frontier’s satisfaction of the performance obligation often differs from the timing of the customer’s payment, which results in the recognition of a contract asset or a contract liability. Frontier recognizes a contract asset or liability when the Company transfers goods or services to a customer and bills an amount which differs from the revenue allocated to the related performance obligations.  The opening and closing balances of Frontier’s contract asset and contract liability balances for the year ended December 31, 2018 are as follows:     Contract Contract  ($ in millions) Assets Liabilities   Balance January 1, 2018 $ 77 (1) $ (60) (3)  Revenue recognized included  in opening contract balance (57) 119  Cash received, excluding amounts  recognized as revenue - (135)  Credits granted, excluding amounts  recognized as revenue 49 -  Other - 5  Balance December 31, 2018 $ 69 (2) $ (71) (4)   (1) Includes $40 million in other current assets and $37 million in other assets. (2) Includes $44 million in other current assets and $25 million in other assets. (3) Includes $41 million in other current liabilities and $19 million in other liabilities. (4) Includes $49 million in other current liabilities and $22 million in other liabilities.  Short-term contract assets, Long-term contract assets, Short-term contract liabilities, and Long-term contract liabilities are included in other current assets, other assets, other current liabilities, and other liabilities, respectively, on our consolidated balance sheet.  The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period.     Revenue from remaining  ($ in millions) performance obligations   2019 $ 2,893  2020 1,209  2021 487  2022 259  2023 141  Thereafter 184  Total $ 5,173  

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2018
Acquisitions [Abstract]
Acquisitions	(4) Acquisitions :  The CTF Acquisition On April 1, 2016, Frontier acquired the wireline operations of Verizon Communications, Inc. in California, Texas and Florida for a purchase price of $ 10,540 million in cash and assumed debt (the CTF Acquisition), pursuant to the February 5, 2015 Securities Purchase Agreement, as amended. In addition, Frontier and Verizon settled the working capital and net debt adjustments with $ 15 million paid to Frontier in October 2016. As a result of the CTF Acquisition, Frontier now operates these former Verizon properties, which included approximately 2.5 million total customers, 2.1 million broadband subscribers, and 1.2 million FiOS video subscribers as of April 1, 2016 (the CTF Operations).  The following unaudited pro forma financial information presents the combined results of operations of Frontier and the CTF Operations as if the CTF Acquisition had occurred as of January 1, 2016. The pro forma information is not necessarily indicative of what the financial position or results of operations actually would have been had the CTF Acquisition been completed as of January 1, 2016. In addition, the unaudited pro forma financial information is not indicative of, nor does it purport to project, the future financial position or operating results of Frontier. The unaudited pro forma financial information excludes acquisition and integration costs and does not give effect to any estimated and potential cost savings or other operating efficiencies that may result from the CTF Acquisition.      (Unaudited)  For the year ended  ($ in millions, except per share amounts) December 31, 2016   Revenue $ 10,255   Operating income $ 1,433   Net loss attributable to Frontier  common shareholders $ (262)    The Connecticut Acquisition On October 24, 2014, Frontier acquired the wireline properties of AT&T Inc. (AT&T) in Connecticut (the Connecticut Acquisition) for a purchase price of $2,018 million in cash, pursuant to the stock purchase agreement dated December 16, 2013, as amended. Following the Connecticut Acquisition, Frontier now owns and operates the wireline business and fiber optic network servicing consumer, commercial and wholesale customers in Connecticut. Frontier also acquired the AT&T U-verse ® video (Vantage) and DISH ® satellite TV customers in Connecticut.  Acquisition and Integration Costs Acquisition costs include legal, financial advisory, accounting, regulatory and other related costs. Integration costs include expenses that are incremental and directly related to the acquisition, and were incurred to integrate the network and information technology platforms and to enable other integration initiatives.  Frontier incurred operating expenses related to the CTF Acquisition and the Connecticut Acquisition, as follows:       For the year ended December 31,  ($ in millions) 2018 2017 2016   Acquisition costs:  CTF Acquisition $ - $ - $ 23   Integration costs:  CTF Acquisition - 25 412  Connecticut Acquisition - - 1  - 25 413   Total acquisition and  integration costs $ - $ 25 $ 436   We also invested $0 million, $34 million and $142 million in capital expenditures related to the CTF Acquisition during the years ended December 31, 2018, 2017, and 2016, respectively.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2018
Accounts Receivable [Abstract]
Accounts Receivable	( 5) Accounts Receivable : The components of accounts receivable, net at December 31, 2018 and 2017 are as follows :       ($ in millions) 2018 2017   Retail and Wholesale $ 745 $ 801  Other 83 87  Less: Allowance for doubtful accounts (105) (69)  Accounts receivable, net $ 723 $ 819   A transition adjustment of $32 million was recorded for the impact of ASC 606 to the Allowance for doubtful accounts as of January 1, 2018 to reflect the cumulative impact of this change on prior periods.  An analysis of the activity in the allowance for doubtful accounts for the years ended December 31, 2018, 2017 and 2016 is as follows:      Charged  (Credited) to  Switched and  Balance at ASC 606 Charged to Nonswitched Balance at  beginning of Transition Other Revenue and Write-offs, net end of  ( $ in millions ) the Period Adjustment Revenue Other of Recoveries the Period   2016 $ 57 $ - $ 164 $ 15 $ (105) $ 131  2017 $ 131 $ - $ 109 $ (22) $ (149) $ 69  2018 $ 69 $ 32 $ 79 $ 14 $ (89) $ 105   We maintain an allowance for doubtful accounts based on our estimate of our ability to collect accounts receivable. The provision for uncollectible amounts was $93 million, $87 million and $179 million for the years ended December 31, 2018, 2017 and 2016, respectively. Excluding the impact of adopting ASC 606, our allowance for doubtful accounts remained relatively stable in 2018. Our allowance for doubtful accounts decreased during 2017 primarily as a result of resolutions of carrier disputes and increased collection efforts on delinquent balances in both our CTF and Legacy markets and increased in 2016 primarily as a result of the customer account balances related to CTF Operations subsequent to the CTF Acquisition. Resolutions reached with carriers resulted in a reduction of our reserves of $9 and $39 million in 2018 and 2017, respectively.

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant And Equipment [Abstract]
Property, Plant And Equipment	(6) Property, Plant and Equipment : Property, plant and equipment, net at December 31, 2018 and 2017 are as follows :       Estimated  ($ in millions) Useful Lives 2018 2017   Land N/A $ 230 $ 231  Buildings and leasehold improvements 40 years 2,302 2,282  General support 5 to 15 years 1,616 1,570  Central office/electronic circuit equipment 5 to 18 years 8,447 8,137  Poles 30 years 1,211 1,095  Cable, fiber and wire 15 to 25 years 11,743 10,997  Conduit 50 years 1,672 1,646  Construction work in progress 436 538  Property, plant and equipment 27,657 26,496  Less: Accumulated depreciation (13,470) (12,119)  Property, plant and equipment, net $ 14,187 $ 14,377   Property, plant, and equipment includes approximately $152 million and $171 million of fixed assets recognized under capital leases as of December 31, 2018 and 2017, respectively.  In 2018 and 2017, we sold certain properties, generating $11 million and $102 million, respectively, in net proceeds, of which $9 million and $97 million, respectively relates to property subject to leasebacks. For these properties, we have deferred $9 million and $66 million, respectively, of related gains that will be amortized over the related lease terms of two years. For year ended December 31, 2018 and 2017, amortization of these deferred gains totaled $36 million and $23 million, respectively, which are included in “Selling, general and administrative expenses” on our consolidated Statement of operations. As of December 31, 2018 and 2017 we had remaining deferred gain balances of $16 million and $43 million, respectively, which were included in “Other liabilities.”  In January 2019, we closed the sale of wireless towers for approximately $76 million. The aggregate carrying value of the towers is approximately $1 million, and the gain on the sale of the towers will be recognized against “Accumulated Depreciation” in our consolidated Statement of operations.  Depreciation expense is principally based on the composite group method. Depreciation expense was as follows :       For the year ended December 31,  ($ in millions) 2018 2017 2016   Depreciation expense $ 1,385 $ 1,485 $ 1,388   We adopted new estimated remaining useful lives for certain plant assets as of October 1, 2018, 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.

Goodwill And Other Intangibles

Goodwill And Other Intangibles	12 Months Ended
	Dec. 31, 2018
Goodwill And Other Intangibles [Abstract]
Goodwill And Other Intangibles	(7) Goodwill and Other Intangibles : The changes in the carrying amount of goodwill, net for the years ended December 31, 2018 and 2017 were as follows :      ($ in millions) Goodwill, net   Balance at January 1, 2017 $ 9,674  Goodwill Impairment (2,748)  CTF Acquisition adjustment 98  Balance at December 31, 2017 7,024  Goodwill impairment (641)  Balance at December 31, 2018 $ 6,383   Accumulated goodwill impairment charges were $3,429 million and $2,788 million as of December 31, 2018 and 2017, respectively.  We are required to perform impairment tests related to our goodwill annually, which we perform as of December 31, or sooner if an indicator of impairment occurs. Due to the continued decline in our stock price we had triggering events in the final three quarters of 2018.  We use a market multiples approach to determine fair value. Marketplace company comparisons and analyst reports within the wireline telecommunications industry have historically supported a range of fair values of multiples between 4.4x and 6.5x annualized EBITDA (defined as operating income, net of acquisition and integration costs, pension/OPEB expense, pension settlement costs, stock-based compensation expense, goodwill impairment, storm-related costs, work stoppage costs, and restructuring costs and other charges, as well as depreciation and amortization). We estimated the enterprise fair value using a multiple of 5.5x EBITDA for each of the first three quarterly evaluations in 2018 and used a multiple of 5.3x EBITDA for our fourth quarter evaluation.  We recorded goodwill impairments totaling $641 million for 2018. The driver for the impairment in the third quarter 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, the impairment was largely driven by a lower enterprise valuation resulting from a reduction in utilized market multiple from 5.5x to 5.3x reflecting the lower outlook for our industry as a whole.  Our second and fourth quarter quantitative assessments in 2017 indicated that the carrying value of the enterprise exceeded its fair value and, therefore, an impairment existed. We elected to early adopt the simplified goodwill testing method under ASU 2017-04, recording goodwill impairments totaling $2,748 million for 2017. The driver for the impairment in the second quarter 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, the impairment was largely driven by a lower enterprise valuation resulting from a reduction in utilized market multiple from 5.8x to 5.5x reflecting the lower outlook for our industry as a whole. The revaluation of our net deferred tax liabilities which resulted from the enactment of Tax Cut and Job Act, caused further goodwill impairment (see Note 13). Our first and third quarter quantitative assessments indicated that the fair value of the enterprise exceeded its carrying value and, therefore, no indication of impairment existed in either period.  The market multiples approach that we use incorporates significant estimates and assumptions related to the forecasted results for the remainder of the year including revenues, expenses, and the achievement of other cost synergies. In developing the market multiple, we also consider observed trends of our industry participants. Declines in our industry outlook could also result in future impairments. Our assessment includes many qualitative factors that require significant judgment. Alternative interpretations of these factors could have resulted in different conclusions regarding the need for, or size of, an impairment. Continued declines in our profitability or cash flows or in the sustained, historically low trading prices of our common stock may result in further impairment.  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, noting no additional impairment was present as of December 31, 2018.  The components of other intangibles at December 31, 2018 and 2017 are as follows :       2018 2017  Gross Net Gross Net  Carrying Accumulated Carrying Carrying Accumulated Carrying  ($ in millions) Amount Amortization Amount Amount Amortization Amount   Other Intangibles:  Customer base $ 5,188 $ (3,848) $ 1,340 $ 5,188 $ (3,294) $ 1,894  Trade name 122 - 122 122 - 122  Royalty agreement 72 (40) 32 72 (25) 47  Total other intangibles $ 5,382 $ (3,888) $ 1,494 $ 5,382 $ (3,319) $ 2,063    Amortization expense was as follows :      For the year ended December 31,  ($ in millions) 2018 2017 2016   Amortization expense $ 569 $ 699 $ 643   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 5.29 years and for our royalty agreement is 2.25 years. Amortization expense based on our current estimate of useful lives, is estimated to be approximately $454 million in 2019, $354 million in 2020, $260 million in 2021, $173 million in 2022, and $95 million in 2023.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2018
Long-Term Debt [Abstract]
Long-Term Debt	(8) Long-Term Debt : The activity in our long-term debt from January 1, 2018 to December 31, 2018 is summarized as follows :        For the year ended December 31, 2018  ($ in millions) January 1, 2018 Payments and Retirements New Borrowings December 31, 2018 Interest Rate at December 31, 2018*   Secured debt issued by Frontier $ 3,511 $ (630) $ 2,365 $ 5,246 6.76%  Unsecured debt issued by Frontier 13,495 (2,198) - 11,297 9.56%  Secured debt issued by subsidiaries 107 - - 107 8.35%  Unsecured debt issued by subsidiaries 750 - - 750 6.90%  Total debt $ 17,863 $ (2,828) $ 2,365 $ 17,400 8.59%   Less: Debt Issuance Costs (183) (178)  Less: Debt Premium/(Discount) (54) (50)  Less: Current Portion (656) (814)  $ 16,970 $ 16,358    * Interest rate includes amortization of debt issuance costs and debt premiums or discounts. The interest rates at December 31, 2018 represent a weighted average of multiple issuances . Additional information regarding our senior unsecured debt, senior secured debt and subsidiary debt at December 31, 2018 and 2017 is as follows:    December 31, 2018 December 31, 2017  Principal Interest Principal Interest  ($ in millions) Outstanding Rate Outstanding Rate   Secured debt issued by Frontier  Term loan due 10/24/2019 (1) $ - $ 245 5.445% (Variable)  Term loan due 3/31/2021 (2) 1,402 5.280% (Variable) 1,483 4.320% (Variable)  Term loan due 10/12/2021 (3) 239 7.405% (Variable) 276 5.445% (Variable)  Revolver due 2/27/2022 (4) 275 5.280% (Variable) -  Term loan due 6/15/2024 (5) 1,716 6.280% (Variable) 1,492 5.320% (Variable)  Second lien notes due 4/1/2026 1,600 8.500% -  IDRB due 5/1/2030 13 6.200% 13 6.200%  Equipment financings 1 0.000% 2 0.000%  Total secured debt issued by Frontier 5,246 3,511   Unsecured debt issued by Frontier  Senior notes due 10/1/2018 - 491 8.125%  Senior notes due 3/15/2019 348 7.125% 404 7.125%  Senior notes due 4/15/2020 172 8.500% 619 8.500%  Senior notes due 9/15/2020 55 8.875% 303 8.875%  Senior notes due 7/1/2021 89 9.250% 490 9.250%  Senior notes due 9/15/2021 220 6.250% 775 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 11,297 13,495   Secured debt issued by subsidiaries  Debentures due 11/15/2031 100 8.500% 100 8.500%  RUS loan contracts due 1/3/2028 7 6.154% 7 6.152%  Total secured debt issued by subsidiaries 107 107   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   Total debt $ 17,400 8.4% (6) $ 17,863 8.1% (6)  (1) Represents borrowings under the 2014 CoBank Credit Agreement, as defined below. (2) Represents borrowings under the JPM Credit Agreement Term Loan A, as defined below. (3) Represents borrowings under the 2016 CoBank Credit Agreement, as defined below. (4) Represents borrowings under the JPM Credit Agreement Revolver, as defined below. (5) Represents borrowings under the JPM Credit Agreement Term Loan B, as defined below. (6) Interest rate represents a weighted average of the stated interest rates of multiple issuances . Term Loan and Revolving Credit Facilities  JP Morgan Credit Facilities  On February 27, 2017, Frontier entered into a first amended and restated credit agreement with JPMorgan Chase Bank, N.A., as administrative agent, and the lenders party thereto, pursuant to which Frontier combined its revolving credit agreement, dated as of June 2, 2014, and its term loan credit agreement, dated as of August 12, 2015. Under the JPM Credit Agreement (as amended to date, the JPM Credit Agreement), Frontier has a $1,625 million senior secured Term Loan A facility (the Term Loan A) maturing on March 31, 2021 , an $850 million secured revolving credit facility maturing on February 27, 2022 (the Revolver), and a $1,740 million senior secured Term Loan B facility (the Term Loan B) maturing on June 15, 2024 . The maturities of the Term Loan A, the Revolver, and the Term Loan B, in each case if still outstanding, will be accelerated in the following circumstances: (i) if, 91 days before the maturity date of any series of Senior Notes maturing in 2020, 2023 and 2024, more than $500 million in principal amount remains outstanding on such series; or (ii) if, 91 days before the maturity date of the first series of Senior Notes maturing in 2021 or 2022, more than $500 million in principal amount remains outstanding, in the aggregate, on the two series of Senior Notes maturing in such year. . As of December 31, 2018, less than $500 million in principal amount remains outstanding on the senior notes due 2020 and on the two series of senior notes maturing in 2021.  The determination of interest rates for each of the facilities under the JPM Credit Agreement is based on margins over the Base Rate (as defined in the JPM Credit Agreement) or over LIBOR, at the election of Frontier. Interest rate margins on the Term Loan A and Revolver (ranging from 0.75% to 1.75% for Base Rate borrowings and 1.75% to 2.75% for LIBOR borrowings) are subject to adjustment based on Frontier’s Leverage Ratio (as defined in the JPM Credit Agreement). The interest rate on the Term Loan A and the Revolver as of December 31, 2018 was LIBOR plus 2.75% . Interest rate margins on the Term Loan B ( 2.75% for Base Rate borrowings and 3.75% for LIBOR borrowings) are not subject to adjustment. The security package under the JPM Credit Agreement includes pledges of the equity interests in certain Frontier subsidiaries and guarantees by certain Frontier subsidiaries. As of December 31, 2018, less than $500 million in principal amount remains outstanding on the senior notes due 2020 and on the two series of senior notes maturing in 2021.  As of December 31, 2018, Frontier had borrowings of $275 million outstanding under the Revolver (with letters of credit issued under the Revolver totaling $71 million).  On January 25, 2018, Frontier amended the JPM Credit Agreement to, among other things, expand the security package to include the interests of certain subsidiaries previously not pledged and replace the leverage ratio maintenance test with a first lien leverage ratio maintenance test. On July 3, 2018, Frontier further amended the JPM Credit Agreement to, among other things, replace certain operating subsidiary equity pledges with pledges of the equity interest of certain direct subsidiaries of Frontier.  CoBank Credit Facilities  Frontier has a $315 million senior term loan facility drawn in October 2016 (as amended to date, the 2016 CoBank Credit Agreement) with CoBank, ACB, as administrative agent, lead arranger and a lender, and the other lenders. Frontier had a separate $350 million senior term loan facility drawn in 2014 (the 2014 CoBank Credit Agreement) with CoBank which was repaid in full on July 3, 2018, as described below under “New Debt Issuances and Debt Reductions.” We refer to the 2014 CoBank Credit Agreement and the 2016 CoBank Credit Agreement collectively as the CoBank Credit Agreements.  The 2016 CoBank Credit Agreement matures on October 12, 2021. Borrowings under the 2016 CoBank Credit Agreement bear interest based on margins over the Base Rate (as defined in the 2016 CoBank Credit Agreement) or over LIBOR, at the election of Frontier. Interest rate margins under the facility will range from 0.875% to 3.875% for Base Rate borrowings and 1.875% to 4.875% for LIBOR borrowings, subject to adjustment based on our Total Leverage Ratio, as defined in the 2016 CoBank Credit Agreement. The interest rate on the facility as of December 31, 2018 was LIBOR plus 4.875% .  On January 25, 2018, Frontier amended the CoBank Credit Agreements to, among other things, expand the security package to include the interests of certain subsidiaries previously not pledged and replace the leverage ratio maintenance test with a first lien leverage ratio maintenance test. On July 3, 2018, Frontier further amended the CoBank Credit Agreements to, among other things, replace certain operating subsidiary equity pledges with pledges of the equity interests of certain direct subsidiaries of Frontier. As of December 31, 2018, we were in compliance with all of our indenture and credit facility covenants.  New Debt Issuances and Debt Reductions:  On March 19, 2018, Frontier completed a private offering of $1,600 million aggregate principal amount of 8.500% Second Lien Secured Notes due 2026 (the “Second Lien Notes”). The Second Lien Notes are guaranteed by each of the Company’s subsidiaries that guarantees its senior secured credit facilities. The guarantees are unsecured obligations of the guarantors and subordinated in right of payment to all of the guarantor’s obligations under the Company’s senior secured credit facilities and certain other permitted future senior indebtedness but equal in right of payment with all other unsubordinated obligations of the guarantors. The Second Lien Notes indenture provides that (a) the aggregate amount of all guaranteed obligations guaranteed by the guarantors are limited and shall not, at any time, exceed the lesser of (x) the principal amount of the Second Lien Notes then outstanding and (y) the Maximum Guarantee Amount (as defined in the Second Lien Notes indenture), and (b) for the avoidance of doubt, nothing in the Second Lien Notes indenture shall, on any date or from time to time, allow the aggregate amount of all such guaranteed obligations guaranteed by the guarantors to cause or result in the Company or any subsidiary violating any indenture governing the Company’s existing senior notes.  The Second Lien Notes are secured on a second-priority basis by all the assets that secure Frontier’s obligations under its senior secured credit facilities on a first-priority basis. The collateral securing the Second Lien Notes and the Company’s senior secured credit facilities is limited to the equity interests of certain subsidiaries of the Company and substantially all personal property of Frontier Video Services, Inc. The Second Lien Notes bear interest at a rate of 8.500% per annum and mature on April 1, 2026. Interest on the Second Lien Notes is payable semi-annually in arrears on April 1 and October 1 of each year, commencing October 1, 2018. On July 3, 2018, the collateral package for the Second Lien Notes was amended to replace certain operating subsidiary equity pledges with pledges of the equity interests of certain direct subsidiaries of Frontier, consistent with amendments made to Frontier’s credit agreements.  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 maturing in 2024. The Company used the incremental borrowings to repay in full the 2014 CoBank Credit Agreement, repay a portion of the 2016 CoBank Credit Agreement and pay certain fees and expenses related to this incremental borrowing.  On June 15, 2017, the Company entered into Increase Joinder No. 1 to the JPM Credit Agreement, pursuant to which the Company borrowed $1,500 million. The Company used the borrowings to fund the open market purchases of certain unsecured Senior notes during 2017.  Upon completion of the CTF Acquisition on April 1, 2016, we assumed additional debt of $600 million, including $200 million aggregate principal amount of 6.75% Senior Notes due May 15, 2027 , $300 million aggregate principal amount of 6.86% Senior Notes due February 1, 2028 and $100 million aggregate principal amount of 8.50% Senior Notes due November 15, 2031.  On October 1, 2018, Frontier retired $431 million principal amount outstanding of 8.125% senior notes due 2018 at maturity.  During 2018, Frontier retired $828 million principal amount of senior indebtedness and made open market purchases of $117 million of senior unsecured notes consisting of $61 million of 8.125% senior notes due 2018 and $56 million of 7.125% senior notes due 2019. Additionally, Frontier used cash proceeds from the $1,600 million Second Lien Notes offering and cash on hand to retire an aggregate principal amount of $1,651 million senior unsecured notes prior to maturity, consisting of $447 million of 8.500% senior notes due 2020, $249 million 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. Additionally, Frontier used cash proceeds from the $240 million incremental borrowing under Term Loan B to repay in full the 2014 CoBank Credit Agreement and repay a portion of the 2016 CoBank Credit Agreement, as well as pay certain fees and expenses related to this incremental borrowing. During 2018, Frontier recorded a gain on early extinguishment of debt of $32 million driven primarily by discounts received on the retirement of certain notes, slightly offset by premiums paid to retire certain notes and unamortized original issuance costs.  During 2017, Frontier used proceeds from Term Loan B (see definition and note discussion above) and cash on hand to retire $763 million of 8.875% Notes due 2020 , $550 million of 8.500% Notes due 2020 , $92 million of 8.125% Notes due 2018 , $30 million of 7.125% Notes due 2019 , and $10 million of 9.250% Notes due 2021 . Frontier recorded a loss of $88 million driven primarily by premiums on the retirement of the notes. Additionally, Frontier used cash available on hand for the scheduled retirement of $210 million of 8.25% Senior Notes at maturity.  During 2016, we completed non-cash debt exchanges including related accrued interest, of $397 million of our 8.25% Notes due April 2017 for approximately $147 million of our 8.50% Notes due April 2020, $66 million of our 8.875% Notes due September 2020, and $188 million of our 10.50% Notes due September 2022. A pretax loss of approximately $7 million was recognized and included in our consolidated statement of operations for the year ended December 31, 2016.  Our scheduled principal payments are as follows as of December 31, 2018. This does not reflect outstanding borrowings under the Revolver.       Principal  ($ in millions) Payments   2019 $ 539  2020 $ 437  2021 $ 1,604  2022 $ 2,706  2023 $ 868  Thereafter $ 10,971     Other Obligations  During 2018 and 2016, Frontier contributed real estate properties with an aggregate fair value of $37 million and $15 million, respectively, for the purpose of funding a portion of its contribution obligations to its qualified defined benefit pension plan. The pension plan obtained independent appraisals of the property and, based on these appraisals, the pension plan recorded the contributions at aggregate fair value of $37 million and $15 million for 2018 and 2016, respectively. Frontier has entered into a lease for the contributed properties. The properties are managed on behalf of the pension plan by an independent fiduciary, and the terms of the lease were negotiated with the fiduciary on an arm’s-length basis.  For properties contributed in 2018, leases have initial terms of 20 years at a combined average aggregate annual rent of approximately $5 million.  For the property contributed in 2016, the lease has an initial term of 15 years at a combined aggregate annual rent of approximately $2 million.  The contribution and leaseback of the properties were treated as financing transactions and, accordingly, Frontier continues to depreciate the carrying value of the property in its financial statements and no gain or loss was recognized. An obligation of $37 and $15 million, respectively, were recorded in our consolidated balance sheet within “Other liabilities” as of December 31, 2018 and 2016, respectively, and the liability is reduced annually by a portion of the lease payments made to the pension plan.  During 2017 and 2016, Frontier modified certain operating leases for vehicles which resulted in the classification as capital leases. These agreements have lease terms of 1 to 7 years. These capital lease obligations are included in our consolidated balance sheet within “Other liabilities” and “Other current liabilities.”   Future minimum payments for finance lease obligations and capital lease obligations as of December 31, 2018 are as follows:       ($ in millions) Finance Lease Obligations Capital Lease Obligations   Year ending December 31:  2019 $ 13 $ 30  2020 14 19  2021 14 13  2022 14 8  2023 15 10  Thereafter 117 4  Total future payments 187 84  Less: Amounts representing interest (109) (15)  Present value of minimum lease payments $ 78 $ 69  

Restructuring And Other Charges

Restructuring And Other Charges	12 Months Ended
	Dec. 31, 2018
Restructuring And Other Charges [Abstract]
Restructuring And Other Charges	(9) Restructuring and Other Charges: As of December 31, 2018, restructuring related liabilities of $18 million pertaining to employee separation charges and accrued costs related to the Transformation Program are included in “Other current liabilities” in our consolidated balance sheet.  Transformation Program During the second quarter of 2018, Frontier announced a multi-year strategic plan with the objective of improving revenues, profitability, and cash flows by enhancing our operations and customer service and support processes (the “Transformation Program”). During the year ended December 31, 2018, we incurred $23 million in costs directly associated with these activities.  We have retained a consulting firm to assist in executing on various aspects of this plan. The consulting firm will be eligible to receive quarterly fees in the event that we achieve targeted improvements in the Company’s profitability, and bonus payments in the event that we achieve targeted improvements in the Company’s profitability or stock price. In certain circumstances, the consulting firm may become eligible to receive the bonus payments and specified fees upon a change of control or termination of the consulting arrangement. Amounts accrued in connection with the consulting agreement are recognized as operating expense under “Restructuring costs and other charges.”  Restructuring Costs 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.  During 2017, restructuring costs and other charges, primarily consisting of severance and other employee-related costs of $68 million, and pension/OPEB benefit enhancements of $5 million, and the loss recorded on the sale of Frontier’s Secure Strategic Partnerships business of $9 million, totaling $82 million in connection with workforce reductions, are included in “Restructuring costs and other charges” in our consolidated statement of operations for the year ended December 31, 2017.  The following is a summary of the changes in the liabilities established for restructuring programs at December 31, 2018:     Restructuring  ($ in millions) Liability  Balance, January 1, 2017 $ 47  Severance costs 68  Cash payments during the period (90)  Balance, December 31, 2017 25  Severance costs 12  Transformation costs 23  Cash payments during the period (42)  Balance, December 31, 2018 $ 18  

Investment And Other Income, Ne

Investment And Other Income, Net	12 Months Ended
	Dec. 31, 2018
Investment And Other Income, Net [Abstract]
Investment And Other Income, Net	 (10) Investment and Other Income, Net : The components of investment and other income, net for the years ended December 31, 2018, 2017 and 2016 are as follows:     For the year ended December 31,  ( $ in millions ) 2018 2017 2016   Interest and dividend income $ 6 $ 6 $ 13  Pension and OPEB benefit (costs) 10 (2) (23)  Gain on expiration/settlement of customer advances - - 13  All other, net (3) (3) 1  Total investment and other income, net $ 13 $ 1 $ 4   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
	Dec. 31, 2018
Capital Stock [Abstract]
Capital Stock	(11) Capital Stock : As of December 31, 2018, Frontier has 175,000,000 , 106,025,000 , and 105,536,000 shares of common stock authorized, issued, and outstanding, respectively. Additionally, Frontier has 50,000,000 shares of preferred stock authorized with no shares of preferred stock issued and outstanding as of December 31,2018.  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
	Dec. 31, 2018
Stock Plans [Abstract]
Stock Plans	(12) Stock Plans : At December 31, 2018, we have seven stock-based compensation plans under which grants were made and awards remained outstanding. No further awards may be granted under six of the plans: the 1996 Equity Incentive Plan (the 1996 EIP), the Amended and Restated 2000 Equity Incentive Plan (the 2000 EIP), the 2009 Equity Incentive Plan (the 2009 EIP), the 2013 Equity Incentive Plan (the 2013 EIP), the Deferred Fee Plan and the Directors’ Equity Plan. At December 31, 2018, there were approximately 5,667,000 shares authorized for grant and approximately 2,607,000 shares available for grant under the 2017 Equity Incentive Plan (the 2017 EIP and together with the 1996 EIP, the 2000 EIP, the 2009 EIP and the 2013 EIPS, the EIPs). Our general policy is to issue treasury shares upon the grant of restricted shares and the exercise of options.  1996, 2000, 2009, 2013, and 2017 Equity Incentive Plans Since the expiration dates of the 1996 EIP, the 2000 EIP, the 2009 EIP, and the 2013 EIP on May 22, 2006, May 14, 2009, May 8, 2013, and May 10, 2017, respectively, no awards have been or may be granted under the 1996 EIP, the 2000 EIP, the 2009 EIP, and the 2013 EIP. 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 under the 2000 EIP 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 On February 15, 2012, Frontier’s Compensation Committee, in consultation with the other non-management directors of Frontier’s Board of Directors and the Committee’s independent executive compensation consultant, adopted the Frontier Long-Term Incentive Plan (the LTIP). LTIP awards are granted in the form of performance shares. The LTIP is currently offered under Frontier’s 2009 EIP, 2013 EIP and 2017 EIP, and participants consist of senior vice presidents and above. The LTIP awards have performance, market and time-vesting conditions.  Beginning in 2012, during the first 90 days of a three -year performance period (a Measurement Period), a target number of performance shares are awarded to each LTIP participant with respect to the Measurement Period. The performance metrics under the LTIP are (1) annual targets for operating cash flow based on a goal set during the first 90 days of each year in the three-year Measurement Period and (2) an overall performance “modifier” set during the first 90 days of the Measurement Period, 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 three-year Measurement Period. Operating cash flow performance is determined at the end of each year and the annual results will be averaged at the end of the three-year Measurement Period to determine the preliminary number of shares earned under the LTIP award. The TSR performance measure is then applied to decrease or increase payouts based on Frontier’s three-year relative TSR performance. LTIP awards, to the extent earned, will be paid out in the form of common stock shortly following the end of the three-year Measurement Period.  On February 11, 2016, the Compensation Committee granted approximately 111,000 performance shares under the LTIP and set the operating cash flow performance goal for 2016, which applies to the first year in the 2016-2018 measurement period, the second year of the 2015-2017 measurement period and the third year of the 2014-2016 measurement period. On February 16, 2017, the Compensation Committee of our Board of Directors granted approximately 157,400 performance shares under the Frontier Long Term Incentive Plan (the LTIP) and set the operating cash flow performance goal for 2017, which applies to the first year in the 2017-2019 measurement period, the second year of the 2016-2018 measurement period and the third year of the 2015-2017 measurement period. On February 14, 2018, the Compensation Committee of our Board of Directors granted approximately 284,000 performance shares under the Frontier Long Term Incentive Plan (the LTIP) and set the operating cash flow performance goal for 2018, which applies to the first year of the 2018-2020 measurement period, the second year of the 2017-2019 measurement period and the third year of the 2016-2018 measurement period. The number of shares of common stock earned at the end of each three-year Measurement Period may be more or less than the number of target performance shares granted as a result of operating cash flow and TSR performance. An executive must maintain a satisfactory performance rating during the Measurement Period and must be employed by Frontier at the end of the three-year Measurement Period in order for the award to vest. The Compensation Committee will determine the number of shares earned for each three-year Measurement Period in February of the year following the end of the Measurement Period.  The following summary presents information regarding LTIP target performance shares as of December 31, 2018 and changes during the three years then ended with regard to LTIP shares awarded under the 2009 EIP, 2013 EIP, and 2017 EIP:     Number of  Shares  (in thousands)  Balance at December 31, 2015 168  LTIP target performance shares granted 111  LTIP target performance shares earned (59)  LTIP target performance shares forfeited (30)  Balance at December 31, 2016 190  LTIP target performance shares granted 211  LTIP target performance shares earned (41)  LTIP target performance shares forfeited (54)  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   For purposes of determining compensation expense, the fair value of each performance share is measured at the end of each reporting period and, therefore, will fluctuate 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 $5 million, $1 million, and $6 million during 2018, 2017 and 2016, respectively, for the LTIP.  Restricted Stock The following summary presents information regarding unvested restricted stock as of December 31, 2018 and changes during the three years then ended with regard to restricted stock under the 2009 EIP, 2013 EIP, and 2017 EIP:     Weighted  Average  Number of Grant Date Aggregate  Shares Fair Value Fair Value  (in thousands) (per share) (in millions)  Balance at December 31, 2015 462 $ 88.95 $ 33  Restricted stock granted 396 $ 65.40 $ 20  Restricted stock vested (248) $ 78.90 $ 13  Restricted stock forfeited (61) $ 76.65  Balance at December 31, 2016 549 $ 78.00 $ 28  Restricted stock granted 454 $ 47.77 $ 3  Restricted stock vested (240) $ 80.86 $ 2  Restricted stock forfeited (130) $ 60.92  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   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, 2018 was $24 million and the weighted average vesting period over which this cost is expected to be recognized is approximately 1.3 years.  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 $13 million, $18 million and $18 million for the years ended December 31, 2018, 2017 and 2016, respectively, has been recorded in connection with these grants.  Non-Employee Directors’ Compensation Plans As of October 1, 2013, stock units are credited to the director’s account in an amount that is 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 are credited to the director’s account quarterly. Directors must also elect to convert the units to either common stock (convertible on a one -to-one basis) or cash upon retirement or death.  Dividends are paid on stock units held by directors at the same rate and at the same time as we pay dividends on shares of our common stock. Dividends on stock units are paid in the form of additional stock units.  There were 9 directors participating in the Director Plans during all or part of 2018. The total plan units earned were 183,791 , 94,034 , and 29,618 in 2018, 2017 and 2016 , respectively .  Since the directors have the option to receive distributions from their stock units in cash, they are considered liability-based awards. Therefore, compensation expense is based on the market value of our common stock at the end of each period.  In connection with the Director Plans, there were compensation costs associated with the issuance of stock units of $(1) million, $(5) million and $0 million in 2018, 2017 and 2016, respectively. Cash compensation associated with the Director Plans was $1 million in 2018, 2017 and 2016. These costs are recognized in “Selling, general and administrative expenses”.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Taxes [Abstract]
Income Taxes	(13) 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, 2018, 2017 and 2016:     2018 2017 2016   Consolidated tax provision at federal statutory rate 21.0 % 35.0 % 35.0 %  State income tax provisions, net of federal income  tax benefit 1.6 1.7 (0.1)  Tax reserve adjustment 0.1 0.1 0.6  Domestic production activities deduction - - (1.9)  Changes in certain deferred tax balances (3.5) (0.4) 5.8  Goodwill impairment (10.4) (19.1) -  Share-based payments (0.5) - -  Federal research and development credit 0.1 0.1 1.0  Deferred Tax Remeasurement - 2017 Tax Reform 0.6 26.1 -  All other, net (0.2) (0.1) (0.2)  Effective tax rate 8.8 % 43.4 % 40.2 %   On December 22, 2017, the U.S. government enacted comprehensive tax legislation 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.  Frontier considered positive and negative evidence in regard to evaluating certain state net operating loss carryforwards in 2018 and the deferred tax asset for the disallowed interest expense deduction under section 163(j), including the development of recent years of pre-tax book losses. On the basis of the evaluation, a valuation allowance has been recorded on the deferred tax assets related to these state NOL carryforwards and reflected in “Changes in certain deferred tax balances”. In addition, a valuation allowance has been recorded on the state deferred tax asset related to the current year disallowed interest expense deduction under section 163(j). The amount of the deferred tax asset considered realizable, however, could be adjusted if estimates of future taxable income during the carryforward period are reduced or increased or if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as our projections for growth.  Income taxes includes the tax impact of $72 million and $608 million related to the goodwill impairment for the years ended December 31, 2018 and 2017, respectively.  Under ASC 605, income tax benefit would have been $7 million more for the year ended December 31, 2018, as a result of changes in pre-tax income as discussed in Note 3.  Income taxes for 2016 include the impact of $36 million of tax benefits resulting primarily from the adjustment of deferred tax balances due to the CTF Acquisition, the impact of $6 million in benefits from the Federal research and development credits, along with a $12 million reversal of benefits related to the domestic production activities deduction.  As of December 31, 2018, amounts pertaining to expected income refunds of $1.5 million and $1.5 million, are included in “Income taxes and other current assets” and “Other assets” in the consolidated balance sheet, respectively.  In 2018, we paid federal and state income tax totaling $4 million. In 2017, we received federal and state income tax refunds totaling $51 million.  The components of the net deferred income tax liability (asset) at December 31 are as follows:      ( $ in millions ) 2018 2017   Deferred income tax liabilities:  Property, plant and equipment basis differences $ 2,182 $ 2,022  Intangibles 18 140  Deferred revenue/expense 66 8  Other, net - 4  $ 2,266 $ 2,174   Deferred income tax assets:  Pension liability 209 176  Tax operating loss carryforward 1,027 960  Employee benefits 176 192  Interest expense deduction  limitation carryforward 104 -  Accrued expenses 41 23  Lease obligations 33 39  Tax credit 37 43  Allowance for doubtful accounts 26 7  Other, net 1 2  1,654 1,442  Less: Valuation allowance (497) (407)  Net deferred income tax asset 1,157 1,035  Net deferred income tax liability $ 1,109 $ 1,139   Our federal net operating loss carryforward as of December 31, 2018 is estimated at $2.4 billion. The federal loss carryforward will begin to expire after 2036, unless otherwise used.  Our state tax operating loss carryforward as of December 31, 2018 is estimated at $9.4 billion. A portion of our state loss carryforward will continue to expire annually through 2038, unless otherwise used.  Our federal research and development credit as of December 31, 2018 is estimated at $19 million. The federal research and development credit will expire between 2034 and 2038, unless otherwise used.  Our various state credits as of December 31, 2018 are estimated at $35 million. The state credits will expire between 2019 and 2023, unless otherwise used.  As of December 31, 2018, Frontier has tax deductible goodwill of $1,952 million.  As of December 31, 2018, Frontier has a valuation allowance of $497 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 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 ) 2018 2017 2016   Income tax expense (benefit):  Current:  Federal $ (1) $ (4) $ (52)  State 6 5 7  Total Current 5 1 (45)   Deferred:  Federal (77) (1,312) (145)  State 10 (72) (60)  Total Deferred (67) (1,384) (205)  Total income tax benefit (62) (1,383) (250)   Income taxes charged (credited) to equity of Frontier:  Utilization of the benefits arising from restricted stock - (1) (5)  Deferred income taxes (benefits) arising from the recognition  of additional pension/OPEB liability (31) 7 (21)   Total income taxes charged (credited) to equity of Frontier (31) 6 (26)  Total income tax benefit $ (93) $ (1,377) $ (276)   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 $11 million as of December 31, 2018, 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 $0 as of December 31, 2018.  Frontier’s policy regarding the classification of interest and penalties is to include these amounts as a component of income tax expense. This treatment of interest and penalties is consistent with prior periods. We are subject to income tax examinations generally for the years 2014 forward for federal and 2008 forward for state filing jurisdictions. We also maintain uncertain tax positions in various state jurisdictions.  The following table sets forth the changes in Frontier’s balance of unrecognized tax benefits for the years ended December 31, 2018 and 2017     ($ in millions) 2018 2017   Unrecognized tax benefits - beginning of year $ 12 $ 16  Gross increases - prior year tax positions - -  Gross increases - current year tax positions - 3  Gross decreases - FIN 48 liability release - (7)  Gross decreases - expired statute of limitations (1) -  Unrecognized tax benefits - end of year $ 11 $ 12  The amounts above exclude $0 and $1 million of accrued interest as of December 31, 2018 and 2017, respectively, that we have recorded and would be payable should Frontier’s tax positions not be sustained.

Net Loss Per Common Share

Net Loss Per Common Share	12 Months Ended
	Dec. 31, 2018
Net Loss Per Common Share [Abstract]
Net Loss Per Common Share	 (14) Net Loss Per Common Share : The reconciliation of the net loss per common share calculation for the years ended December 31, 2018, 2017 and 2016 is as follows :          ( $ in millions and shares in thousands, except per share amounts ) 2018 2017 2016   Net loss used for basic and diluted earnings (loss)  per share:  Net loss attributable to Frontier common shareholders $ (750) $ (2,018) $ (587)  Less: Dividends paid on unvested restricted stock awards - (2) (3)  Total basic net loss attributable to Frontier  common shareholders $ (750) $ (2,020) $ (590)   Effect of loss related to dilutive stock units - - -  Total diluted net loss attributable to Frontier  common shareholders $ (750) $ (2,020) $ (590)   Basic earnings (loss) per share:  Total weighted average shares and unvested restricted stock  awards outstanding - basic 91,523 78,409 78,142  Less: Weighted average unvested restricted stock awards (1,840) (673) (535)  Total weighted average shares outstanding - basic 89,683 77,736 77,607   Basic net loss per share attributable to Frontier  common shareholders $ (8.37) $ (25.99) $ (7.61)   Diluted earnings (loss) per share:  Total weighted average shares outstanding - basic 89,683 77,736 77,607  Effect of dilutive shares - - -  Total weighted average shares outstanding - diluted 89,683 77,736 77,607   Diluted net loss per share attributable to Frontier  common shareholders $ (8.37) $ (25.99) $ (7.61)     In calculating diluted net loss per common share for the years ended December 31, 2018, 2017, and 2016 the effect of all common stock equivalents is excluded from the computation as the effect would be antidilutive.  Stock Options For the years ended December 31, 2018, 2017 and 2016, options to purchase 1,334 , 1,334 and 2,667 shares, respectively, 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, 2018, 2017 and 2016, we had 348,093 , 203,952 and 125,431 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.  Mandatory Convertible Preferred Stock The impact of the common share equivalents associated with approximately 19,250,000 shares of Series A Preferred stock described above were not included in the calculation of diluted EPS as of December 31, 2017, as their impact was antidilutive.

Comprehensive Loss

Comprehensive Loss	12 Months Ended
	Dec. 31, 2018
Comprehensive Loss [Abstract]
Comprehensive Loss	(15) Comprehensive Loss : Comprehensive income (loss) consists of net income (loss) and other gains and losses affecting shareholders’ investment and pension/postretirement benefit (OPEB) liabilities that, under GAAP, are excluded from net income (loss).  The components of accumulated other comprehensive loss, net of tax at December 31, 2018, 2017 and 2016, and changes for the years then ended, are as follows :     ($ in millions) Pension Costs OPEB Costs Total  Balance at December 31, 2015 (a) $ (363) $ 10 $ (353)  Other comprehensive income (loss) before  reclassifications (65) 11 (54)   Amounts reclassified from accumulated  other comprehensive income (loss) 25 (5) 20   Net current-period other comprehensive income (loss) (40) 6 (34)   Balance at December 31, 2016 (a) (403) 16 (387)   Other comprehensive income (loss) before  reclassifications (12) (31) (43)   Amounts reclassified from accumulated  other comprehensive income (loss) 70 (6) 64   Net current-period other comprehensive income (loss) 58 (37) 21   Balance at December 31, 2017 (a) (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 (a) $ (489) $ 26 $ (463)   (a) Pension and OPEB amounts are net of deferred tax balances of $250 million, $223 million, $231 million and $211 million as of December 31, 2018, 2017, 2016, and 2015, respectively.  As a result of the pension settlement accounting discussed in Note 18, Frontier recorded pension settlement charges totaling $41 million ( $31 million net of tax) and $83 million ( $51 million net of tax), which were reclassified from accumulated Other comprehensive income (loss) during 2018 and 2017, respectively.  As a result of the CTF Acquisition, the Frontier Communications Pension Plan (the Plan) was remeasured. This remeasurement resulted in a decrease in the discount rate from 4.50% at December 31, 2015 to 4.00% at the date of the CTF Acquisition. This change in the discount rate resulted in a remeasurement charge to Other comprehensive income (loss) of $105 million during 2016 .  The significant items reclassified from each component of accumulated other comprehensive loss for the years ended December 31, 2018, 2017 and 2016 are as follows :       Amount Reclassified from  ($ in millions) Accumulated Other Comprehensive Loss (a)   Affected Line Item in the  Details about Accumulated Other Statement where  Comprehensive Loss Components 2018 2017 2016 Net loss is Presented   Amortization of Pension Cost Items (b)  Actuarial gains (losses) $ (24) $ (30) $ (40)  Pension settlement costs (41) (83) -  Reclassifications, pretax (65) (113) (40) Loss before income taxes  Tax Impact 18 43 15 Income tax (expense) benefit  Reclassifications, net of tax $ (47) $ (70) $ (25) Net loss   Amortization of OPEB Cost Items (b)  Prior-service credits (costs) $ 9 $ 9 $ 9  Actuarial gains (losses) (3) - (1)  Reclassifications, pretax 6 9 8 Loss before income taxes  Tax impact (2) (3) (3) Income tax (expense) benefit  Reclassifications, net of tax $ 4 $ 6 $ 5 Net loss      (a) Amounts in parentheses indicate losses. (b) These accumulated other comprehensive loss components are included in the computation of net periodic pension and OPEB costs (see Note 18 - Retirement Plans for additional details ) . 

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Information [Abstract]
Segment Information	(16) 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
	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Quarterly Financial Data	(17) Quarterly Financial Data (Unaudited ) :       2018  First Second Third Fourth Total  ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year   Revenue (3) $ 2,199 $ 2,162 $ 2,126 $ 2,124 $ 8,611   Operating income (loss) (2)(3) 366 367 (33) 127 827   Net loss attributable to Frontier  common shareholders (2)(3) (33) (72) (426) (219) (750)   Basic net loss per share attributable  to Frontier common shareholders (1)(2)(3) $ (0.44) $ (0.92) $ (4.11) $ (2.12) $ (8.37)   Diluted net loss per share attributable  to Frontier common shareholders (1)(2)(3) $ (0.44) $ (0.92) $ (4.11) $ (2.12) $ (8.37)  (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 and our preferred stock conversion during 2018. (2) During the fourth quarter of 2018, we recorded a goodwill impairment charge of $641 million ( $572 million after-tax). Refer to Note 7 for further details. (3) Effective January 1, 2018, we adopted ASU 2014-09, “Revenue from Contracts with Customers,” as modified (ASC 606) using the modified retrospective method. Under this approach, prior period results were not restated to reflect the impact of ASC 606, resulting in limited comparability between 2017 and 2018 operating results.      2017  First Second Third Fourth Total  ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year   Revenue $ 2,356 $ 2,304 $ 2,251 $ 2,217 $ 9,128   Operating income (loss) (3) 317 (375) 322 (1,747) (1,483)   Net loss attributable to Frontier  common shareholders (1) (2) (129) (715) (92) (1,082) (2,018)   Basic net loss per share attributable  to Frontier common shareholders (1) (2) $ (1.67) $ (9.20) $ (1.19) $ (13.91) $ (25.99)   Diluted net loss per share attributable  to Frontier common shareholders (1) (2) $ (1.67) $ (9.21) $ (1.19) $ (13.91) $ (25.99)    (1) During the fourth quarter of 2017, we recorded a goodwill impairment charge of $ 2,078 million ( $ 1,822 million after-tax). Refer to Note 7 for further details. (2) 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. (3) Effective January 1, 2018, Frontier adopted ASU 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The standard requires certain benefit costs to be reclassified from operating expenses to non-operating expenses. This change in policy was applied using a retrospective approach and, accordingly, we have reclassified $2 million of net operating expenses as non-operating expense for the year ended December 31, 2017. Additional pension settlement costs of $83 million for the year ended December 31, 2017 were reclassified from operating expense to non-operating expense.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2018
Retirement Plans [Abstract]
Retirement Plans	(18) 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, 2018, 2017 and 2016, 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 4.30% as of December 31, 2018 for its qualified pension plan, compared to rates of 3.70% and 4.10% in 2017 and 2016, respectively. The discount rate for postretirement plans as of December 31, 2018 was a range of 4.30% to 4.40% compared to a range of 3.70% to 3.80% in 2017 and 4.10% to 4.30% in 2016.  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, 2018, lump sum pension settlement payments to terminated or retired individuals amounted to $254 million, which exceeded the settlement threshold of $216 million, and as a result, Frontier recognized non-cash settlement charges totaling $41 million during 2018. 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.  Our Pension Plan assets decreased from $2,674 million at December 31, 2017 to $2,348 million at December 31, 2018, a decrease of $326 million, or 12% . This decrease was a result of benefit payments of $317 million inclusive of lump sum payments and investment management and administrative fees, partially offset by contributions of $150 million and negative investment returns of $159 million.  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 2018 and 2017. For 2019, we will 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 74% , as of December 31, 2018.  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, 2018 and 2017 and the components of total pension benefit cost for the years ended December 31, 2018, 2017 and 2016:       ( $ in millions ) 2018 2017   Change in projected benefit obligation (PBO)  PBO at beginning of year $ 3,363 $ 3,465  Service cost 90 97  Interest cost 125 127  Actuarial (gain) loss (88) 214  Benefits paid (63) (59)  Settlements (254) (486)  Special termination benefits - 5  PBO at end of year $ 3,173 $ 3,363   Change in plan assets  Fair value of plan assets at beginning of year $ 2,674 $ 2,766  Actual return on plan assets (159) 378  Employer contributions 150 206  Settlements (254) (486)  Differential payment received from Verizon - (131)  Benefits paid (63) (59)  Fair value of plan assets at end of year $ 2,348 $ 2,674   Funded status $ (825) $ (689)   Amounts recognized in the consolidated balance sheet  Pension and other postretirement benefits - current $ - $ -  Pension and other postretirement benefits - noncurrent $ (825) $ (689)  Accumulated other comprehensive loss $ 754 $ 556        ( $ in millions ) 2018 2017 2016   Components of total pension benefit cost  Service cost $ 90 $ 97 $ 88  Interest cost on projected benefit obligation 125 127 122  Expected return on plan assets (192) (186) (168)  Amortization of unrecognized loss 24 30 40  Net periodic pension benefit cost 47 68 82  Pension settlement costs 41 83 -  Special termination benefits - 5 23  Total pension benefit cost $ 88 $ 156 $ 105    The expected amortization of deferred unrecognized loss, included in Other comprehensive loss, in 2019 is $57 million.  We capitalized $26 million, $26 million and $25 million of pension and OPEB expense into the cost of our capital expenditures during the years ended December 31, 2018, 2017 and 2016, respectively, as the costs relate to our engineering and plant construction activities .  The plan’s weighted average asset allocations at December 31, 2018 and 2017 by asset category are as follows :       2018 2017  Asset category:  Equity securities 48 % 50 %  Debt securities 40 % 40 %  Alternative investments 12 % 10 %  Total 100 % 100 %   The plan’s expected benefit payments over the next 10 years are as follows :       ($ in millions) Amount   2019 $ 256  2020 252  2021 251  2022 246  2023 244  2024-2028 1,165  Total $ 2,414   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 6 for further discussion of contributed real estate.  In 2017, required pension plan contributions were approximately $75 million, net of the Differential (as defined below), consisting of all cash payments. As part of the CTF Acquisition, Verizon was required to make a cash payment to Frontier for the difference in assets initially transferred by Verizon into the Pension Plan and the related obligation (the Differential). In 2017, we received the $131 million Differential payment from Verizon, and have remitted an equivalent amount to the Pension Plan as of December 31, 2017. As the Differential was reflected as a receivable of the Pension Plan at December 31, 2016, the cash funding had no impact to plan assets.  In 2016, required pension plan contributions were $28 million, consisting of cash payments of $13 million and the contribution of real property with a fair value of $15 million. See Note 8 for further discussion of contributed real estate.  The accumulated benefit obligation for the plan was $3,106 million and $3,268 million at December 31, 2018 and 2017, respectively.  Assumptions used in the computation of annual pension costs and valuation of the year-end obligations were as follows :      2018 2017 2016  Discount rate - used at year end to value obligation 4.30 % 3.70 % 4.10 %  Discount rate - used at beginning of year to compute annual cost 3.70 % 4.10 % 4.50 %  Expected long-term rate of return on plan assets 7.50 % 7.50 % 7.50 %  Rate of increase in compensation levels 2.00 % 2.50 % 2.50 %   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, 2018 and 2017 and the components of total postretirement benefit cost for the years ended December 31, 2018, 2017 and 2016 .       ( $ in millions) 2018 2017   Change in benefit obligation  Benefit obligation at beginning of year $ 1,016 $ 925  Service cost 21 21  Interest cost 38 40  Plan participants' contributions 7 7  Actuarial (gain) loss (79) 54  Benefits paid (38) (31)  Benefit obligation at end of year $ 965 $ 1,016   Change in plan assets  Fair value of plan assets at beginning of year $ - $ -  Plan participants' contributions 7 7  Employer contribution 31 24  Benefits paid (38) (31)  Fair value of plan assets at end of year $ - $ -   Funded status $ (965) $ (1,016)   Amounts recognized in the consolidated balance sheet  Pension and other postretirement benefits - current $ (39) $ (29)  Pension and other postretirement benefits - noncurrent $ (926) $ (987)  Accumulated other comprehensive (gain) loss $ (41) $ 33        ( $ in millions ) 2018 2017 2016   Components of total postretirement benefit cost  Service cost $ 21 $ 21 $ 19  Interest cost on projected benefit obligation 38 40 37  Amortization of prior service (credit) costs (9) (9) (9)  Amortization of unrecognized loss 3 - 1  Net periodic postretirement benefit cost 53 52 48  Special termination benefits - - 3  Total postretirement benefit cost $ 53 $ 52 $ 51   The expected amortization of prior service credit in 2019 is $9 million and the expected amortization of unrecognized loss in 2019 is $3 million.  Assumptions used in the computation of annual OPEB costs and valuation of the year-end OPEB obligations were as follows :      2018 2017 2016  Discount rate - used at year end to value obligation 4.30% - 4.40% 3.70% - 3.80% 4.10% - 4.30%  Discount rate - used to compute annual cost 3.70% - 3.80% 4.10% - 4.30% 4.50% - 4.70%   The OPEB plan’s expected benefit payments over the next 10 years are as follows :       ($ in millions) Gross Benefit Medicare Part D Subsidy Total   2019 $ 39 $ - $ 39  2020 45 - 45  2021 50 - 50  2022 54 - 54  2023 57 - 57  2024-2028 320 2 322  Total $ 565 $ 2 $ 567   For purposes of measuring year-end benefit obligations, we used, depending on medical plan coverage for different retiree groups, a 6.50% annual rate of increase in the per-capita cost of covered medical benefits, gradually decreasing to 5.00% in the year 2025 and remaining at that level thereafter. The effect of a 1.00% increase in the assumed medical cost trend rates for each future year on the aggregate of the service and interest cost components of the total postretirement benefit cost would be $1 million and the effect on the accumulated postretirement benefit obligation for health benefits would be $19 million. The effect of a 1.00% decrease in the assumed medical cost trend rates for each future year on the aggregate of the service and interest cost components of the total postretirement benefit cost would be $(1) million and the effect on the accumulated postretirement benefit obligation for health benefits would be $(19) million . The amounts in accumulated other comprehensive (gain) loss before tax that have not yet been recognized as components of net periodic benefit cost at December 31, 2018 and 2017 are as follows :       Pension Plan OPEB  ( $ in millions ) 2018 2017 2018 2017  Net actuarial loss $ 754 $ 556 $ (28) $ 54  Prior service cost (credit) - - (13) (21)  Total $ 754 $ 556 $ (41) $ 33   The amounts recognized as a component of accumulated other comprehensive loss for the years ended December 31, 2018 and 2017 are as follows :      Pension Plan OPEB  ( $ in millions ) 2018 2017 2018 2017  Accumulated other comprehensive (gain) loss at  beginning of year $ 556 $ 647 $ 33 $ (29)   Net actuarial loss recognized during year (24) (30) (3) -  Prior service credit recognized during year - - 9 9  Net actuarial (gain) loss occurring during year 263 22 (80) 53  Settlement loss recognized (41) (83) - -  Net amount recognized in comprehensive income  (loss) for the year 198 (91) (74) 62  Accumulated other comprehensive (gain) loss at  end of year $ 754 $ 556 $ (41) $ 33   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 $45 million, $48 million and $48 million for 2018, 2017 and 2016, respectively .

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	12 Months Ended
	Dec. 31, 2018
Fair Value Of Financial Instruments [Abstract]
Fair Value Of Financial Instruments	(19) 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, 2018 and 2017 :       Fair Value Measurements at December 31, 2018  ( $ in millions ) Total Level 1 Level 2 Level 3  Cash and Cash Equivalents $ 36 $ 36 $ - $ -  U.S. Government Obligations 46 - 46 -  Corporate and Other Obligations 425 - 425 -  Common Stock 420 420 - -  Interest in Registered Investment Companies (1) 262 262 - -  Interest in Limited Partnerships and  Limited Liability Companies 155 - - 155  Total investments at fair value $ 1,344 $ 718 $ 471 $ 155  Common/Collective Trusts (1) 1,031  Interest and Dividend Receivable 6  Due from Broker for Securities Sold 20  Receivable Associated with Insurance Contract 7  Due to Broker for Securities Purchased (60)  Total Plan Assets, at Fair Value $ 2,348        Fair Value Measurements at December 31, 2017  ( $ in millions ) Total Level 1 Level 2 Level 3  Cash and Cash Equivalents $ 37 $ 37 $ - $ -  U.S. Government Obligations 30 - 30 -  Corporate and Other Obligations 448 - 448 -  Common Stock 523 523 - -  Interest in Registered Investment Companies (1) 324 324 - -  Interest in Limited Partnerships and  Limited Liability Companies 115 - - 115  Total investments at fair value $ 1,477 $ 884 $ 478 $ 115  Common/Collective Trusts (1) 1,215  Interest and Dividend Receivable 6  Due from Broker for Securities Sold 40  Receivable Associated with Insurance Contract 7  Due to Broker for Securities Purchased (71)  Total Plan Assets, at Fair Value $ 2,674   (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 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 $131 million and $167 million, as of December 31, 2018 and 2017, 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 18 - Retirement Plans. There have been no reclassifications of investments between Levels 1, 2 or 3 assets during the years ended December 31, 2018 or 2017.  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, 2018 and 2017 :      Interest in Limited Partnerships and Limited Liability Companies  ( $ in millions ) 2018 2017  Balance, beginning of year $ 115 $ 118  Realized gains 11 12  Unrealized gains (losses) 3 (2)  Purchases 37 -  Sales and distributions (11) (13)  Balance, end of year $ 155 $ 115   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, 2018 :      Liquidation Capitalization  ( $ in millions ) Fair Value Period Rate  Interest in Limited Partnerships and Limited  Liability Companies (d)   MS IFHF SVP LP Cayman (a) $ 1 4 years N/A  RII World Timberfund, LLC (b) 5 3 years N/A  426 E. Casino Road, LLC (c) 16 N/A 7.00%  100 Comm Drive, LLC (c) 9 N/A 7.75%  100 CTE Drive, LLC (c) 11 N/A 9.50%  6430 Oakbrook Parkway, LLC (c) 26 N/A 7.75%  8001 West Jefferson, LLC (c) 27 N/A 8.75%  1500 MacCorkle Ave SE, LLC (c) 14 N/A 8.50%  400 S. Pike Road West, LLC (c) 1 N/A 8.50%  601 N. US 131, LLC (c) 1 N/A 9.50%  9260 E. Stockton Blvd., LLC (c) 6 N/A 7.25%  120 E. Lime Street, LLC (c) 8 N/A 9.00%  610 N. Morgan Street, LLC (c) 30 N/A 8.50%  Total Interest in Limited Partnerships and Limited  Liability Companies $ 155   (a) 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. (b) 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 three years. (c) 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. (d) 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, 2018 and 2017. For the other financial instruments including cash, accounts receivable, restricted cash, long-term debt due within one year, accounts payable and other current liabilities, the carrying amounts approximate fair value due to the relatively short maturities of those instruments .      2018 2017  Carrying Carrying  ($ in millions) Amount Fair Value Amount Fair Value   Long-term debt $ 16,358 $ 11,942 $ 16,970 $ 13,994   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
	Dec. 31, 2018
Commitments And Contingencies [Abstract]
Commitments And Contingencies	(20) 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 June 2015, Frontier accepted the Federal Communications Commission’s (FCC) offer of support to price cap carriers under the Connect America Fund (CAF) Phase II program, which is intended to provide long-term support for broadband in high cost unserved or underserved areas. This program provides $332 million in annual support, including $49 million in annual support related to the properties acquired in the CTF Acquisition, through 2020 to make available 10 Mbps downstream/1 Mbps upstream broadband service to approximately 774,000 households across certain of the 29 states where we now operate. To the extent we do not enable the required number of households with 10 Mbps downstream/1 Mbps upstream broadband service by the end of the CAF Phase II term, we will be required to return a portion of the funds previously received.  In August 2018, the FCC concluded its Connect America Fund Phase II auction to award $200 million in funding over ten years in areas where its original offer of support in 2015 was not accepted by carriers. The results of the Phase II auction have no impact on Frontier’s current $332 million in CAF Phase II support. Frontier did participate in this auction and the amount it won is immaterial to our results.  In September 2018, Frontier filed applications to be eligible to bid in two upcoming FCC spectrum auctions: Auction 101 (28 GHz) and Auction 102 (24 GHz). Auction 101 ended on January 24, 2019 and offered two 425 MHz licenses in 1,536 counties. Auction 102, which is scheduled to start March 14, 2019, will offer seven 100 MHz licenses in 416 Partial Economic Areas. Both auctions remain under the FCC’s quiet period rules; therefore, Frontier can make no comment on the extent of its participation in Auction 101 or plans to participate in Auction 102 at this time.  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. 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 is 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 asserts, 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, in connection with certain disclosures relating to the CTF Acquisition. The complaint seeks, among other things, damages and equitable and injunctive relief. We dispute the allegations in the complaint described above 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.  We are currently defending an intellectual property lawsuit initiated by Sprint Communications which alleges that the VoIP services that we offer to our customers infringe on certain of the plaintiff’s patents. While we intend to defend this lawsuit vigorously, we cannot at this time predict the outcome of this lawsuit or reasonably estimate a possible range of loss.  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.  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.  Future minimum rental commitments for all long-term noncancelable operating leases as of December 31, 2018 are as follows :    ($ in millions) Operating Leases   Year ending December 31:  2019 $ 73  2020 18  2021 14  2022 13  2023 11  Thereafter 89   Total minimum lease payments $ 218  Total rental expense included in our consolidated statements of operations for the years ended December 31, 2018, 2017 and 2016 was $102 million, $106 million and $137 million, respectively.  We are party to contracts with several unrelated long-distance carriers. The contracts provide fees based on traffic they carry for us subject to minimum monthly fees.  At December 31, 2018, the estimated future payments for obligations under our noncancelable long-distance contracts and service agreements are as follows :       ($ in millions) Amount   Year ending December 31:  2019 $ 44  2020 35  2021 26  2022 2  2023 2  Thereafter 7   Total $ 116  At December 31, 2018, we have outstanding performance letters of credit as follows :       ($ in millions) Amount   CNA Financial Corporation (CNA) $ 49  AIG Insurance 43  Zurich 52  All other 1  Total $ 145   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 a letter of credit in their favor. Zurich could potentially draw against this letter of credit if we failed to reimburse Zurich in accordance with the terms of our agreement. The amount of the letter 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, 2018
Description Of Business And Summary Of Significant Accounting Policies [Abstract]
Description of Business	(a) Description of Business : Frontier Communications Corporation (Frontier) is the fourth largest Incumbent Local Exchange Carrier (ILEC) in the United States, with approximately 4.5 million customers, 3.7 million broadband subscribers and 21,200 employees, operating in 29 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.  Effective April 1, 2016, Frontier’s scope of operations and balance sheet changed materially as a result of the completion of the CTF Acquisition, as described in Note 4 - Acquisitions. Historical financial data presented for Frontier is not indicative of the future financial position or operating results for Frontier, and includes the results of the CTF Operations, as defined in Note 4 – Acquisitions, from the date of acquisition on April 1, 2016.
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, 2018, 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.  On July 10, 2017, we effected a one for fifteen reverse stock split of our common stock. The reverse stock split reduced the number of common shares issued (which includes outstanding shares and treasury shares) from approximately 1,193,000,000 shares to 80,000,000 shares, and reduced shares outstanding from 1,178,000,000 shares to 79,000,000 shares. In addition, and at the same time, the total number of shares of common stock that Frontier is authorized to issue changed from 1,750,000,000 shares to 175,000,000 shares. There was no change in the par value of the common stock, and no fractional shares were issued. All share and per share amounts in the financial statements and footnotes have been retroactively adjusted for all periods presented to give effect to the reverse stock split. As a result of our reverse stock split the conversion rates of our Series A Preferred Stock were proportionately adjusted.
Cash Equivalents	(c) Cash Equivalents : We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents. Restricted cash of $50 million is included within “Other assets” on our consolidated balance sheet as of December 31, 2018 and $14 million is included within “Income taxes and other current assets” on our consolidated balance sheet as of December 31, 2017. These amounts represent funds held as collateral by certain insurance carriers.
Revenue Recognition	(d) Revenue Recognition : Revenue for Voice services, Data & Internet services, Video services, Switched and nonswitched access services will be recognized as the service is provided. 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. 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.  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 $213 million, $216 million, and $217 million for the years ended December 31, 2018, 2017, and 2016, respectively, and video franchise fees of $47 million, $52 million, and $37 million for the years ended December 31, 2018, 2017, and 2016, respectively, that we have recorded on a gross basis in our consolidated statements of operations and included within “Revenue” and “Network related expenses.  In 2015, we accepted the FCC’s Connect America Fund (CAF) Phase II offer of support, which is a successor to and augments the USF frozen high cost support that we had been receiving pursuant to a 2011 FCC order. Upon completion of the 2016 acquisition of properties in California, Texas, and Florida with Verizon (CTF Acquisition), Frontier assumed the CAF Phase II support and related obligations that Verizon had previously accepted with regard to California and Texas. We are recognizing these subsidies into revenue on a straight-line basis.  For additional information about our revenue policies and other required disclosures in accordance with ASC 606, refer to Note 3.
Property, Plant and Equipment	(e) 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. 
Goodwill And Other Intangibles	(f) Goodwill and Other Intangibles : Goodwill represents the excess of purchase price over the fair value of identifiable tangible and intangible net assets acquired. We undertake studies to determine the fair values of assets and liabilities acquired and allocate purchase prices to assets and liabilities, including property, plant and equipment, goodwill and other identifiable intangibles. We examine the carrying value of our goodwill and trade name annually as of December 31, or more frequently, as circumstances warrant, to determine whether there are any impairment losses. We test for goodwill impairment at the “operating segment” level, as that term is defined in GAAP.  We determined that we have one operating segment based on a number of factors that our management uses to evaluate and run our business operations, including similarities of customers, products and technology. We tested goodwill for impairment as of December 31, 2018 as a result of the continued decline in share price of our common stock since September 30, 2018, the date of our last goodwill impairment test. Refer to Note 7 for a discussion of our goodwill impairment testing and results as of December 31, 2018. We adopted ASU No. 2017-04, “Simplifying the Test for Goodwill Impairment” during 2017 in conjunction with our goodwill impairment assessment.  Frontier amortizes finite-lived intangible assets over their estimated useful lives on the accelerated method of sum of the years digits. We review such intangible assets at least annually as of December 31 to assess whether any potential impairment exists and 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	(g) 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 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 tangible and intangible assets to determine whether any changes are required.
Income Taxes And Deferred Income Taxes	(h) 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.
Stock Plans	(i) 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	(j) 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 14 – Net Loss Per Common Share.

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Schedule Of Impact Of Adoption	   For the year ended December 31, 2018  Amounts without  Adjustments Adoption of  ($ in millions) As Reported for ASC 606 ASC 606   Revenue $ 8,611 $ (15) $ 8,596  Operating expenses 7,784 15 7,799  Operating income $ 827 $ (30) $ 797  
Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Schedule Of Impact Of Adoption	   For the year ended December 31,  2017 2016  Impact of Impact of  Adoption of Adoption of  ($ in millions) As Reported ASU 2017-07 As Restated As Reported ASU 2017-07 As Restated  Operating expenses:  Network related expenses $ 1,959 $ (1) $ 1,958 $ 1,887 $ (11) $ 1,876  Selling, general and administrative expenses $ 2,018 $ (1) $ 2,017 $ 2,093 $ (12) $ 2,081  Pension settlement costs $ 83 $ (83) $ - $ - $ - $ -   Non-operating income/expenses:  Investment and other income, net $ 3 $ (2) $ 1 $ 27 $ (23) $ 4  Pension settlement costs $ - $ 83 $ 83 $ - $ - $ -  

ASC 606 Adoption And Revenue _2

ASC 606 Adoption And Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2018
ASC 606 Adoption And Revenue Recognition [Abstract]
Schedule Of Prior Period Impact Of New Accounting Pronouncement	   As Reported ASC 606 Adjusted  ($ in millions) December 31, 2017 Transition Adjustment January 1, 2018  Assets  Accounts receivable, net $ 819 $ (32) $ 787  Contract acquisition costs $ - $ 87 $ 87  Other current assets $ 64 $ 4 $ 68  Property, plant and equipment, net $ 14,377 $ 15 $ 14,392  Other assets $ 97 $ 127 $ 224   Liabilities and Equity  Other current liabilities $ 330 $ 5 $ 335  Other liabilities $ 317 $ (9) $ 308  Deferred income taxes $ 1,139 $ 51 $ 1,190  Accumulated deficit $ (2,263) $ 154 $ (2,109)  
Schedule Of Impact Of New Accounting Pronouncement On Balance Sheet And Income Statement	The following table summarizes the impacts of adopting ASC 606 on Frontier’s consolidated balance sheet as of December 31, 2018.     December 31, 2018  Impact of Amounts Excluding  ($ in millions) As Reported Adoption of ASC 606 Adoption of ASC 606  Assets  Accounts receivable, net $ 723 $ 44 $ 767  Contract acquisition costs $ 107 $ (107) $ -  Prepaid expenses $ 86 $ 3 $ 89  Other current assets $ 60 $ (4) $ 56  Property, plant and equipment, net $ 14,187 $ (56) $ 14,131  Other assets $ 265 $ (117) $ 148   Liabilities and Equity  Other current liabilities $ 303 $ (6) $ 297  Other liabilities $ 281 $ 10 $ 291  Deferred income taxes $ 1,109 $ (57) $ 1,052  Accumulated deficit $ (2,752) $ (184) $ (2,936)   The following tables summarize the impacts of adopting ASC 606 on Frontier’s statement of operations for the year ended December 31, 2018.     For the year ended December 31, 2018  Impact of Amounts Excluding  As Reported Adoption of ASC 606 Adoption of ASC 606  ($ in millions)  Revenue $ 8,611 $ (15) $ 8,596   Operating expenses:  Network access expenses 1,441 (3) 1,438  Network related expenses 1,898 - 1,898  Selling, general and administrative expenses 1,815 19 1,834  Other operating expenses 2,630 (1) 2,629  Total operating expenses 7,784 15 7,799   Operating income (loss) $ 827 $ (30) $ 797  
Disaggregation Of Revenue	   For the year ended December 31,  2018  Amounts  Impact of Excluding  Adoption of Adoption of  ($ in millions) As Reported ASC 606 ASC 606 2017 2016  Data and Internet services $ 3,878 $ (103) $ 3,775 $ 3,862 (1) $ 3,693 (1)  Voice services 2,721 (152) 2,569 2,864 2,886  Video services 1,085 99 1,184 1,304 1,244  Other 544 (193) 351 322 276  Revenue from contracts  with customers 8,228 (349) 7,879 8,352 (1) 8,099 (1)  Subsidy and other regulatory revenue 383 334 717 776 797  Total revenue $ 8,611 $ (15) $ 8,596 $ 9,128 (1) $ 8,896 (1)   For the year ended December 31,  2018  Amounts  Impact of Excluding  Adoption of Adoption of  ($ in millions) As Reported ASC 606 ASC 606 2017 2016  Consumer $ 4,380 $ (116) $ 4,264 $ 4,476 $ 4,383  Commercial 3,848 (233) 3,615 3,876 (1) 3,716 (1)  Revenue from contracts  with customers 8,228 (349) 7,879 8,352 (1) 8,099 (1)  Subsidy and other regulatory revenue 383 334 717 776 797  Total revenue $ 8,611 $ (15) $ 8,596 $ 9,128 (1) $ 8,896 (1)   (1) Includes revenue from Frontier Secure Strategic Partnerships business, which was sold in May of 2017, of $40 million and $84 million for the years ended December 31, 2017 and 2016, respectively.
Changes In Contract Assets And Contract Liabilities	   Contract Contract  ($ in millions) Assets Liabilities   Balance January 1, 2018 $ 77 (1) $ (60) (3)  Revenue recognized included  in opening contract balance (57) 119  Cash received, excluding amounts  recognized as revenue - (135)  Credits granted, excluding amounts  recognized as revenue 49 -  Other - 5  Balance December 31, 2018 $ 69 (2) $ (71) (4)   (1) Includes $40 million in other current assets and $37 million in other assets. (2) Includes $44 million in other current assets and $25 million in other assets. (3) Includes $41 million in other current liabilities and $19 million in other liabilities. (4) Includes $49 million in other current liabilities and $22 million in other liabilities.
Performance Obligations, Revenue	   Revenue from remaining  ($ in millions) performance obligations   2019 $ 2,893  2020 1,209  2021 487  2022 259  2023 141  Thereafter 184  Total $ 5,173  

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Acquisitions [Abstract]
Unaudited Pro Forma Information	   (Unaudited)  For the year ended  ($ in millions, except per share amounts) December 31, 2016   Revenue $ 10,255   Operating income $ 1,433   Net loss attributable to Frontier  common shareholders $ (262)  
Schedule Of Acquisition And Integration Costs	   For the year ended December 31,  ($ in millions) 2018 2017 2016   Acquisition costs:  CTF Acquisition $ - $ - $ 23   Integration costs:  CTF Acquisition - 25 412  Connecticut Acquisition - - 1  - 25 413   Total acquisition and  integration costs $ - $ 25 $ 436  

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2018
Accounts Receivable [Abstract]
Accounts Receivable	   ($ in millions) 2018 2017   Retail and Wholesale $ 745 $ 801  Other 83 87  Less: Allowance for doubtful accounts (105) (69)  Accounts receivable, net $ 723 $ 819  
Schedule Of Allowance For Doubtful Accounts	   Charged  (Credited) to  Switched and  Balance at ASC 606 Charged to Nonswitched Balance at  beginning of Transition Other Revenue and Write-offs, net end of  ( $ in millions ) the Period Adjustment Revenue Other of Recoveries the Period   2016 $ 57 $ - $ 164 $ 15 $ (105) $ 131  2017 $ 131 $ - $ 109 $ (22) $ (149) $ 69  2018 $ 69 $ 32 $ 79 $ 14 $ (89) $ 105  

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant And Equipment [Abstract]
Property, Plant And Equipment, Net	   Estimated  ($ in millions) Useful Lives 2018 2017   Land N/A $ 230 $ 231  Buildings and leasehold improvements 40 years 2,302 2,282  General support 5 to 15 years 1,616 1,570  Central office/electronic circuit equipment 5 to 18 years 8,447 8,137  Poles 30 years 1,211 1,095  Cable, fiber and wire 15 to 25 years 11,743 10,997  Conduit 50 years 1,672 1,646  Construction work in progress 436 538  Property, plant and equipment 27,657 26,496  Less: Accumulated depreciation (13,470) (12,119)  Property, plant and equipment, net $ 14,187 $ 14,377  
Schedule Of Depreciation Expense	   For the year ended December 31,  ($ in millions) 2018 2017 2016   Depreciation expense $ 1,385 $ 1,485 $ 1,388  

Goodwill And Other Intangibles

Goodwill And Other Intangibles (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill And Other Intangibles [Abstract]
Schedule Of Goodwill Activity	   ($ in millions) Goodwill, net   Balance at January 1, 2017 $ 9,674  Goodwill Impairment (2,748)  CTF Acquisition adjustment 98  Balance at December 31, 2017 7,024  Goodwill impairment (641)  Balance at December 31, 2018 $ 6,383  
Components Of Other Intangibles	   2018 2017  Gross Net Gross Net  Carrying Accumulated Carrying Carrying Accumulated Carrying  ($ in millions) Amount Amortization Amount Amount Amortization Amount   Other Intangibles:  Customer base $ 5,188 $ (3,848) $ 1,340 $ 5,188 $ (3,294) $ 1,894  Trade name 122 - 122 122 - 122  Royalty agreement 72 (40) 32 72 (25) 47  Total other intangibles $ 5,382 $ (3,888) $ 1,494 $ 5,382 $ (3,319) $ 2,063  
Schedule Of Amortization Expense	   For the year ended December 31,  ($ in millions) 2018 2017 2016   Amortization expense $ 569 $ 699 $ 643  

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Long-Term Debt [Abstract]
Long-Term Debt	      For the year ended December 31, 2018  ($ in millions) January 1, 2018 Payments and Retirements New Borrowings December 31, 2018 Interest Rate at December 31, 2018*   Secured debt issued by Frontier $ 3,511 $ (630) $ 2,365 $ 5,246 6.76%  Unsecured debt issued by Frontier 13,495 (2,198) - 11,297 9.56%  Secured debt issued by subsidiaries 107 - - 107 8.35%  Unsecured debt issued by subsidiaries 750 - - 750 6.90%  Total debt $ 17,863 $ (2,828) $ 2,365 $ 17,400 8.59%   Less: Debt Issuance Costs (183) (178)  Less: Debt Premium/(Discount) (54) (50)  Less: Current Portion (656) (814)  $ 16,970 $ 16,358    * Interest rate includes amortization of debt issuance costs and debt premiums or discounts. The interest rates at December 31, 2018 represent a weighted average of multiple issuances .
Schedule Of Unsecured Debt	    December 31, 2018 December 31, 2017  Principal Interest Principal Interest  ($ in millions) Outstanding Rate Outstanding Rate   Secured debt issued by Frontier  Term loan due 10/24/2019 (1) $ - $ 245 5.445% (Variable)  Term loan due 3/31/2021 (2) 1,402 5.280% (Variable) 1,483 4.320% (Variable)  Term loan due 10/12/2021 (3) 239 7.405% (Variable) 276 5.445% (Variable)  Revolver due 2/27/2022 (4) 275 5.280% (Variable) -  Term loan due 6/15/2024 (5) 1,716 6.280% (Variable) 1,492 5.320% (Variable)  Second lien notes due 4/1/2026 1,600 8.500% -  IDRB due 5/1/2030 13 6.200% 13 6.200%  Equipment financings 1 0.000% 2 0.000%  Total secured debt issued by Frontier 5,246 3,511   Unsecured debt issued by Frontier  Senior notes due 10/1/2018 - 491 8.125%  Senior notes due 3/15/2019 348 7.125% 404 7.125%  Senior notes due 4/15/2020 172 8.500% 619 8.500%  Senior notes due 9/15/2020 55 8.875% 303 8.875%  Senior notes due 7/1/2021 89 9.250% 490 9.250%  Senior notes due 9/15/2021 220 6.250% 775 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 11,297 13,495   Secured debt issued by subsidiaries  Debentures due 11/15/2031 100 8.500% 100 8.500%  RUS loan contracts due 1/3/2028 7 6.154% 7 6.152%  Total secured debt issued by subsidiaries 107 107   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   Total debt $ 17,400 8.4% (6) $ 17,863 8.1% (6)  (1) Represents borrowings under the 2014 CoBank Credit Agreement, as defined below. (2) Represents borrowings under the JPM Credit Agreement Term Loan A, as defined below. (3) Represents borrowings under the 2016 CoBank Credit Agreement, as defined below. (4) Represents borrowings under the JPM Credit Agreement Revolver, as defined below. (5) Represents borrowings under the JPM Credit Agreement Term Loan B, as defined below. (6) Interest rate represents a weighted average of the stated interest rates of multiple issuances .
Debt Maturities By Year	   Principal  ($ in millions) Payments   2019 $ 539  2020 $ 437  2021 $ 1,604  2022 $ 2,706  2023 $ 868  Thereafter $ 10,971  
Schedule Of Future Minimum Lease Obligations	   ($ in millions) Finance Lease Obligations Capital Lease Obligations   Year ending December 31:  2019 $ 13 $ 30  2020 14 19  2021 14 13  2022 14 8  2023 15 10  Thereafter 117 4  Total future payments 187 84  Less: Amounts representing interest (109) (15)  Present value of minimum lease payments $ 78 $ 69  

Restructuring And Other Charg_2

Restructuring And Other Charges (Tables)	12 Months Ended
	Dec. 31, 2018
Restructuring And Other Charges [Abstract]
Changes In Restructuring Reserve	   Restructuring  ($ in millions) Liability  Balance, January 1, 2017 $ 47  Severance costs 68  Cash payments during the period (90)  Balance, December 31, 2017 25  Severance costs 12  Transformation costs 23  Cash payments during the period (42)  Balance, December 31, 2018 $ 18  

Investment And Other Income, _2

Investment And Other Income, Net (Tables)	12 Months Ended
	Dec. 31, 2018
Investment And Other Income, Net [Abstract]
Components Of Investment And Other Income, Net	   For the year ended December 31,  ( $ in millions ) 2018 2017 2016   Interest and dividend income $ 6 $ 6 $ 13  Pension and OPEB benefit (costs) 10 (2) (23)  Gain on expiration/settlement of customer advances - - 13  All other, net (3) (3) 1  Total investment and other income, net $ 13 $ 1 $ 4  

Stock Plans (Tables)

Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Stock Plans [Abstract]
LTIP Target Performance Shares	   Number of  Shares  (in thousands)  Balance at December 31, 2015 168  LTIP target performance shares granted 111  LTIP target performance shares earned (59)  LTIP target performance shares forfeited (30)  Balance at December 31, 2016 190  LTIP target performance shares granted 211  LTIP target performance shares earned (41)  LTIP target performance shares forfeited (54)  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  
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, 2015 462 $ 88.95 $ 33  Restricted stock granted 396 $ 65.40 $ 20  Restricted stock vested (248) $ 78.90 $ 13  Restricted stock forfeited (61) $ 76.65  Balance at December 31, 2016 549 $ 78.00 $ 28  Restricted stock granted 454 $ 47.77 $ 3  Restricted stock vested (240) $ 80.86 $ 2  Restricted stock forfeited (130) $ 60.92  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  

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Taxes [Abstract]
Reconciliation Of Provision For Income Taxes	   2018 2017 2016   Consolidated tax provision at federal statutory rate 21.0 % 35.0 % 35.0 %  State income tax provisions, net of federal income  tax benefit 1.6 1.7 (0.1)  Tax reserve adjustment 0.1 0.1 0.6  Domestic production activities deduction - - (1.9)  Changes in certain deferred tax balances (3.5) (0.4) 5.8  Goodwill impairment (10.4) (19.1) -  Share-based payments (0.5) - -  Federal research and development credit 0.1 0.1 1.0  Deferred Tax Remeasurement - 2017 Tax Reform 0.6 26.1 -  All other, net (0.2) (0.1) (0.2)  Effective tax rate 8.8 % 43.4 % 40.2 %  
Components Of Net Deferred Income Tax Liability (Asset)	   ( $ in millions ) 2018 2017   Deferred income tax liabilities:  Property, plant and equipment basis differences $ 2,182 $ 2,022  Intangibles 18 140  Deferred revenue/expense 66 8  Other, net - 4  $ 2,266 $ 2,174   Deferred income tax assets:  Pension liability 209 176  Tax operating loss carryforward 1,027 960  Employee benefits 176 192  Interest expense deduction  limitation carryforward 104 -  Accrued expenses 41 23  Lease obligations 33 39  Tax credit 37 43  Allowance for doubtful accounts 26 7  Other, net 1 2  1,654 1,442  Less: Valuation allowance (497) (407)  Net deferred income tax asset 1,157 1,035  Net deferred income tax liability $ 1,109 $ 1,139  
Schedule of Components Of Income Tax Expense (Benefit)	   ( $ in millions ) 2018 2017 2016   Income tax expense (benefit):  Current:  Federal $ (1) $ (4) $ (52)  State 6 5 7  Total Current 5 1 (45)   Deferred:  Federal (77) (1,312) (145)  State 10 (72) (60)  Total Deferred (67) (1,384) (205)  Total income tax benefit (62) (1,383) (250)   Income taxes charged (credited) to equity of Frontier:  Utilization of the benefits arising from restricted stock - (1) (5)  Deferred income taxes (benefits) arising from the recognition  of additional pension/OPEB liability (31) 7 (21)   Total income taxes charged (credited) to equity of Frontier (31) 6 (26)  Total income tax benefit $ (93) $ (1,377) $ (276)  
Changes In The Balance Of Unrecognized Tax Benefits	   ($ in millions) 2018 2017   Unrecognized tax benefits - beginning of year $ 12 $ 16  Gross increases - prior year tax positions - -  Gross increases - current year tax positions - 3  Gross decreases - FIN 48 liability release - (7)  Gross decreases - expired statute of limitations (1) -  Unrecognized tax benefits - end of year $ 11 $ 12  

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2018
Net Loss Per Common Share [Abstract]
Calculation Of Net Loss Per Common Share	   ( $ in millions and shares in thousands, except per share amounts ) 2018 2017 2016   Net loss used for basic and diluted earnings (loss)  per share:  Net loss attributable to Frontier common shareholders $ (750) $ (2,018) $ (587)  Less: Dividends paid on unvested restricted stock awards - (2) (3)  Total basic net loss attributable to Frontier  common shareholders $ (750) $ (2,020) $ (590)   Effect of loss related to dilutive stock units - - -  Total diluted net loss attributable to Frontier  common shareholders $ (750) $ (2,020) $ (590)   Basic earnings (loss) per share:  Total weighted average shares and unvested restricted stock  awards outstanding - basic 91,523 78,409 78,142  Less: Weighted average unvested restricted stock awards (1,840) (673) (535)  Total weighted average shares outstanding - basic 89,683 77,736 77,607   Basic net loss per share attributable to Frontier  common shareholders $ (8.37) $ (25.99) $ (7.61)   Diluted earnings (loss) per share:  Total weighted average shares outstanding - basic 89,683 77,736 77,607  Effect of dilutive shares - - -  Total weighted average shares outstanding - diluted 89,683 77,736 77,607   Diluted net loss per share attributable to Frontier  common shareholders $ (8.37) $ (25.99) $ (7.61)  

Comprehensive Loss (Tables)

Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2018
Comprehensive Loss [Abstract]
Accumulated Other Comprehensive Loss, Net Of Tax	   ($ in millions) Pension Costs OPEB Costs Total  Balance at December 31, 2015 (a) $ (363) $ 10 $ (353)  Other comprehensive income (loss) before  reclassifications (65) 11 (54)   Amounts reclassified from accumulated  other comprehensive income (loss) 25 (5) 20   Net current-period other comprehensive income (loss) (40) 6 (34)   Balance at December 31, 2016 (a) (403) 16 (387)   Other comprehensive income (loss) before  reclassifications (12) (31) (43)   Amounts reclassified from accumulated  other comprehensive income (loss) 70 (6) 64   Net current-period other comprehensive income (loss) 58 (37) 21   Balance at December 31, 2017 (a) (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 (a) $ (489) $ 26 $ (463)   (a) Pension and OPEB amounts are net of deferred tax balances of $250 million, $223 million, $231 million and $211 million as of December 31, 2018, 2017, 2016, and 2015, respectively.
Reclassification Out Of AOCI	     Amount Reclassified from  ($ in millions) Accumulated Other Comprehensive Loss (a)   Affected Line Item in the  Details about Accumulated Other Statement where  Comprehensive Loss Components 2018 2017 2016 Net loss is Presented   Amortization of Pension Cost Items (b)  Actuarial gains (losses) $ (24) $ (30) $ (40)  Pension settlement costs (41) (83) -  Reclassifications, pretax (65) (113) (40) Loss before income taxes  Tax Impact 18 43 15 Income tax (expense) benefit  Reclassifications, net of tax $ (47) $ (70) $ (25) Net loss   Amortization of OPEB Cost Items (b)  Prior-service credits (costs) $ 9 $ 9 $ 9  Actuarial gains (losses) (3) - (1)  Reclassifications, pretax 6 9 8 Loss before income taxes  Tax impact (2) (3) (3) Income tax (expense) benefit  Reclassifications, net of tax $ 4 $ 6 $ 5 Net loss      (a) Amounts in parentheses indicate losses. (b) These accumulated other comprehensive loss components are included in the computation of net periodic pension and OPEB costs (see Note 18 - Retirement Plans for additional details )

Quarterly Financial Data (Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Quarterly Financial Information	   2018  First Second Third Fourth Total  ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year   Revenue (3) $ 2,199 $ 2,162 $ 2,126 $ 2,124 $ 8,611   Operating income (loss) (2)(3) 366 367 (33) 127 827   Net loss attributable to Frontier  common shareholders (2)(3) (33) (72) (426) (219) (750)   Basic net loss per share attributable  to Frontier common shareholders (1)(2)(3) $ (0.44) $ (0.92) $ (4.11) $ (2.12) $ (8.37)   Diluted net loss per share attributable  to Frontier common shareholders (1)(2)(3) $ (0.44) $ (0.92) $ (4.11) $ (2.12) $ (8.37)  (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 and our preferred stock conversion during 2018. (2) During the fourth quarter of 2018, we recorded a goodwill impairment charge of $641 million ( $572 million after-tax). Refer to Note 7 for further details. (3) Effective January 1, 2018, we adopted ASU 2014-09, “Revenue from Contracts with Customers,” as modified (ASC 606) using the modified retrospective method. Under this approach, prior period results were not restated to reflect the impact of ASC 606, resulting in limited comparability between 2017 and 2018 operating results.      2017  First Second Third Fourth Total  ($ in millions, except per share amounts) Quarter Quarter Quarter Quarter Year   Revenue $ 2,356 $ 2,304 $ 2,251 $ 2,217 $ 9,128   Operating income (loss) (3) 317 (375) 322 (1,747) (1,483)   Net loss attributable to Frontier  common shareholders (1) (2) (129) (715) (92) (1,082) (2,018)   Basic net loss per share attributable  to Frontier common shareholders (1) (2) $ (1.67) $ (9.20) $ (1.19) $ (13.91) $ (25.99)   Diluted net loss per share attributable  to Frontier common shareholders (1) (2) $ (1.67) $ (9.21) $ (1.19) $ (13.91) $ (25.99)    (1) During the fourth quarter of 2017, we recorded a goodwill impairment charge of $ 2,078 million ( $ 1,822 million after-tax). Refer to Note 7 for further details. (2) 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. (3) Effective January 1, 2018, Frontier adopted ASU 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The standard requires certain benefit costs to be reclassified from operating expenses to non-operating expenses. This change in policy was applied using a retrospective approach and, accordingly, we have reclassified $2 million of net operating expenses as non-operating expense for the year ended December 31, 2017. Additional pension settlement costs of $83 million for the year ended December 31, 2017 were reclassified from operating expense to non-operating expense.

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Plans [Abstract]
Projected Benefit Obligations, Fair Values Of Plan Assets And Amounts Recognized In The Balance Sheet	   ( $ in millions ) 2018 2017   Change in projected benefit obligation (PBO)  PBO at beginning of year $ 3,363 $ 3,465  Service cost 90 97  Interest cost 125 127  Actuarial (gain) loss (88) 214  Benefits paid (63) (59)  Settlements (254) (486)  Special termination benefits - 5  PBO at end of year $ 3,173 $ 3,363   Change in plan assets  Fair value of plan assets at beginning of year $ 2,674 $ 2,766  Actual return on plan assets (159) 378  Employer contributions 150 206  Settlements (254) (486)  Differential payment received from Verizon - (131)  Benefits paid (63) (59)  Fair value of plan assets at end of year $ 2,348 $ 2,674   Funded status $ (825) $ (689)   Amounts recognized in the consolidated balance sheet  Pension and other postretirement benefits - current $ - $ -  Pension and other postretirement benefits - noncurrent $ (825) $ (689)  Accumulated other comprehensive loss $ 754 $ 556  
Net Periodic Benefit Cost	   ( $ in millions ) 2018 2017 2016   Components of total pension benefit cost  Service cost $ 90 $ 97 $ 88  Interest cost on projected benefit obligation 125 127 122  Expected return on plan assets (192) (186) (168)  Amortization of unrecognized loss 24 30 40  Net periodic pension benefit cost 47 68 82  Pension settlement costs 41 83 -  Special termination benefits - 5 23  Total pension benefit cost $ 88 $ 156 $ 105  
Weighted Average Asset Allocations, By Asset Category	   2018 2017  Asset category:  Equity securities 48 % 50 %  Debt securities 40 % 40 %  Alternative investments 12 % 10 %  Total 100 % 100 %  
Expected Benefit Payments Over The Next Ten Years	   ($ in millions) Amount   2019 $ 256  2020 252  2021 251  2022 246  2023 244  2024-2028 1,165  Total $ 2,414  
Schedule Of Assumptions Used	   2018 2017 2016  Discount rate - used at year end to value obligation 4.30 % 3.70 % 4.10 %  Discount rate - used at beginning of year to compute annual cost 3.70 % 4.10 % 4.50 %  Expected long-term rate of return on plan assets 7.50 % 7.50 % 7.50 %  Rate of increase in compensation levels 2.00 % 2.50 % 2.50 %  
Schedule Of Changes In Projected benefit Obligations For OPEB	   ( $ in millions) 2018 2017   Change in benefit obligation  Benefit obligation at beginning of year $ 1,016 $ 925  Service cost 21 21  Interest cost 38 40  Plan participants' contributions 7 7  Actuarial (gain) loss (79) 54  Benefits paid (38) (31)  Benefit obligation at end of year $ 965 $ 1,016   Change in plan assets  Fair value of plan assets at beginning of year $ - $ -  Plan participants' contributions 7 7  Employer contribution 31 24  Benefits paid (38) (31)  Fair value of plan assets at end of year $ - $ -   Funded status $ (965) $ (1,016)   Amounts recognized in the consolidated balance sheet  Pension and other postretirement benefits - current $ (39) $ (29)  Pension and other postretirement benefits - noncurrent $ (926) $ (987)  Accumulated other comprehensive (gain) loss $ (41) $ 33  
Schedule Of Net Benefit Costs For OPEB	   ( $ in millions ) 2018 2017 2016   Components of total postretirement benefit cost  Service cost $ 21 $ 21 $ 19  Interest cost on projected benefit obligation 38 40 37  Amortization of prior service (credit) costs (9) (9) (9)  Amortization of unrecognized loss 3 - 1  Net periodic postretirement benefit cost 53 52 48  Special termination benefits - - 3  Total postretirement benefit cost $ 53 $ 52 $ 51  
Schedule Of Assumptions Used For OPEB	   2018 2017 2016  Discount rate - used at year end to value obligation 4.30% - 4.40% 3.70% - 3.80% 4.10% - 4.30%  Discount rate - used to compute annual cost 3.70% - 3.80% 4.10% - 4.30% 4.50% - 4.70%  
Schedule Of Expected Benefit Payments For OPEB	   ($ in millions) Gross Benefit Medicare Part D Subsidy Total   2019 $ 39 $ - $ 39  2020 45 - 45  2021 50 - 50  2022 54 - 54  2023 57 - 57  2024-2028 320 2 322  Total $ 565 $ 2 $ 567  
Net Periodic Benefit Cost Not Yet Recognized	   Pension Plan OPEB  ( $ in millions ) 2018 2017 2018 2017  Net actuarial loss $ 754 $ 556 $ (28) $ 54  Prior service cost (credit) - - (13) (21)  Total $ 754 $ 556 $ (41) $ 33  
Amounts Recognized As A Componenet Of AOCI	   Pension Plan OPEB  ( $ in millions ) 2018 2017 2018 2017  Accumulated other comprehensive (gain) loss at  beginning of year $ 556 $ 647 $ 33 $ (29)   Net actuarial loss recognized during year (24) (30) (3) -  Prior service credit recognized during year - - 9 9  Net actuarial (gain) loss occurring during year 263 22 (80) 53  Settlement loss recognized (41) (83) - -  Net amount recognized in comprehensive income  (loss) for the year 198 (91) (74) 62  Accumulated other comprehensive (gain) loss at  end of year $ 754 $ 556 $ (41) $ 33  

Fair Value Of Financial Instr_2

Fair Value Of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Of Financial Instruments [Abstract]
Pension Plan Assets Measured At Fair Value on Recurring Basis	      Fair Value Measurements at December 31, 2018  ( $ in millions ) Total Level 1 Level 2 Level 3  Cash and Cash Equivalents $ 36 $ 36 $ - $ -  U.S. Government Obligations 46 - 46 -  Corporate and Other Obligations 425 - 425 -  Common Stock 420 420 - -  Interest in Registered Investment Companies (1) 262 262 - -  Interest in Limited Partnerships and  Limited Liability Companies 155 - - 155  Total investments at fair value $ 1,344 $ 718 $ 471 $ 155  Common/Collective Trusts (1) 1,031  Interest and Dividend Receivable 6  Due from Broker for Securities Sold 20  Receivable Associated with Insurance Contract 7  Due to Broker for Securities Purchased (60)  Total Plan Assets, at Fair Value $ 2,348        Fair Value Measurements at December 31, 2017  ( $ in millions ) Total Level 1 Level 2 Level 3  Cash and Cash Equivalents $ 37 $ 37 $ - $ -  U.S. Government Obligations 30 - 30 -  Corporate and Other Obligations 448 - 448 -  Common Stock 523 523 - -  Interest in Registered Investment Companies (1) 324 324 - -  Interest in Limited Partnerships and  Limited Liability Companies 115 - - 115  Total investments at fair value $ 1,477 $ 884 $ 478 $ 115  Common/Collective Trusts (1) 1,215  Interest and Dividend Receivable 6  Due from Broker for Securities Sold 40  Receivable Associated with Insurance Contract 7  Due to Broker for Securities Purchased (71)  Total Plan Assets, at Fair Value $ 2,674   (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 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 $131 million and $167 million, as of December 31, 2018 and 2017, 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 18 - Retirement Plans.
Changes In Fair Value of Plan's Level 3 Assets	   Interest in Limited Partnerships and Limited Liability Companies  ( $ in millions ) 2018 2017  Balance, beginning of year $ 115 $ 118  Realized gains 11 12  Unrealized gains (losses) 3 (2)  Purchases 37 -  Sales and distributions (11) (13)  Balance, end of year $ 155 $ 115  
Redemption Of The Plan's Level 3 Investments	   Liquidation Capitalization  ( $ in millions ) Fair Value Period Rate  Interest in Limited Partnerships and Limited  Liability Companies (d)   MS IFHF SVP LP Cayman (a) $ 1 4 years N/A  RII World Timberfund, LLC (b) 5 3 years N/A  426 E. Casino Road, LLC (c) 16 N/A 7.00%  100 Comm Drive, LLC (c) 9 N/A 7.75%  100 CTE Drive, LLC (c) 11 N/A 9.50%  6430 Oakbrook Parkway, LLC (c) 26 N/A 7.75%  8001 West Jefferson, LLC (c) 27 N/A 8.75%  1500 MacCorkle Ave SE, LLC (c) 14 N/A 8.50%  400 S. Pike Road West, LLC (c) 1 N/A 8.50%  601 N. US 131, LLC (c) 1 N/A 9.50%  9260 E. Stockton Blvd., LLC (c) 6 N/A 7.25%  120 E. Lime Street, LLC (c) 8 N/A 9.00%  610 N. Morgan Street, LLC (c) 30 N/A 8.50%  Total Interest in Limited Partnerships and Limited  Liability Companies $ 155   (a) 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. (b) 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 three years. (c) 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. (d) 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	   2018 2017  Carrying Carrying  ($ in millions) Amount Fair Value Amount Fair Value   Long-term debt $ 16,358 $ 11,942 $ 16,970 $ 13,994  

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies [Abstract]
Future Minimum Rental Commitments for All Long-Term Noncancelable Operating Leases	   ($ in millions) Operating Leases   Year ending December 31:  2019 $ 73  2020 18  2021 14  2022 13  2023 11  Thereafter 89   Total minimum lease payments $ 218  
Future Payments for Obligations under Noncancelable Long Distance Contracts and Service Agreements	   ($ in millions) Amount   Year ending December 31:  2019 $ 44  2020 35  2021 26  2022 2  2023 2  Thereafter 7   Total $ 116  
Outstanding Performance Letters of Credit	   ($ in millions) Amount   CNA Financial Corporation (CNA) $ 49  AIG Insurance 43  Zurich 52  All other 1  Total $ 145  

Description Of Business And S_3

Description Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) customer in Millions	Jul. 10, 2017shares	Dec. 31, 2018USD ($)statesegmentcustomershares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)	Jul. 09, 2017shares
Number of customers | customer		4.5
Number of subscribers | customer		3.7
Number of employees | $		21,200
Number of states of operation | state		29
Reverse stock split, conversion ratio	0.0667
Common stock, shares issued (in shares)	80,000,000	106,025,000	79,352,000
Common stock, shares outstanding (in shares)	79,000,000	105,536,000	78,441,000
Common Stock, Shares Authorized	175,000,000	175,000,000	175,000,000
Reverse Stock Split, Fractional Shares Issued	0
Restricted Cash | $			$ 14,000,000
Restricted cash | $		$ 50,000,000
Customer surcharges | $		213,000,000	216,000,000	$ 217,000,000
Video franchise fees | $		$ 47,000,000	$ 52,000,000	$ 37,000,000
Number of operating regions | segment		1
Previously Reported [Member]
Common stock, shares issued (in shares)					1,193,000,000
Common stock, shares outstanding (in shares)					1,178,000,000
Common Stock, Shares Authorized					1,750,000,000

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sale leasebacks, gains			$ 9	$ 66
Scenario, Forecast [Member] | Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification adjustment	$ 80
Subsequent Event [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sale leasebacks, gains		$ 16

Recent Accounting Pronounceme_4

Recent Accounting Pronouncements (Schedule Of Impact Of Adoption Of ASU 2014-09) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 2,124	$ 2,126	$ 2,162	$ 2,199	$ 2,217	$ 2,251	$ 2,304	$ 2,356	$ 8,611	$ 9,128	$ 8,896
Operating expenses									7,784
Operating income (loss)	$ 127	$ (33)	$ 367	$ 366	$ (1,747)	$ 322	$ (375)	$ 317	827	$ (1,483)	$ 911
Amounts Excluding Adoption of ASC 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue									8,596
Operating expenses									7,799
Operating income (loss)									797
Accounting Standards Update 2014-09 [Member] | Impact Of Adoption Of ACS 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue									(15)
Operating expenses									15
Operating income (loss)									$ (30)

Recent Accounting Pronounceme_5

Recent Accounting Pronouncements (Schedule Of Impact Of Adoption Of ASU 2017-07) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Network related expenses	$ 1,898	$ 1,958	$ 1,876
Selling, general and administrative expenses	1,815	2,017	2,081
Investment and other income, net	13	1	4
Pension settlement costs	$ 41	83
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Network related expenses		1,959	1,887
Selling, general and administrative expenses		2,018	2,093
Pension settlement costs		83
Investment and other income, net		3	27
Restatement Adjustment [Member] | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Network related expenses		(1)	(11)
Selling, general and administrative expenses		(1)	(12)
Pension settlement costs		(83)
Investment and other income, net		(2)	$ (23)
Pension settlement costs		$ 83

ASC 606 Adoption And Revenue _3

ASC 606 Adoption And Revenue Recognition (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Short-term contract assets	$ 44	$ 40
Long-term contract assets	25	37
Short-term contract liabilities	49	41
Long-term contract liabilities	$ 22	19
Expected customer life	3 years 9 months 18 days
Short-term contract acquisition costs	$ 107	87
Long-term contract acquisition costs	127	117
Revenue recognized for satisfaction of performance obligations	119
Revenue from contracts with customers, performance obligation	5,173
Allowance for doubtful accounts	105		$ 69
Short-term Contract with Customer [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Short-term contract assets	44
Short-term contract liabilities	12
Long-term Contract with Customer [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term contract assets	25
Long-term contract liabilities	9
Contributions In Aid Of Construction [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue recognized for satisfaction of performance obligations	41
Impact Of Adoption Of ACS 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for doubtful accounts	12
Impact Of Adoption Of ACS 606 [Member] | Short-term Contract with Customer [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Short-term contract assets		40
Short-term contract liabilities		12
Impact Of Adoption Of ACS 606 [Member] | Long-term Contract with Customer [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term contract assets		37
Long-term contract liabilities		9
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized contract cost incurred during the period	138
Amortized deferred costs	108
Accounting Standards Update 2014-09 [Member] | Impact Of Adoption Of ACS 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Short-term contract acquisition costs	$ (107)		$ 87
Allowance for doubtful accounts		$ 32

ASC 606 Adoption And Revenue _4

ASC 606 Adoption And Revenue Recognition (Schedule Of Prior Period Impact Of New Accounting Pronouncement) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 723	$ 787	$ 819
Contract acquisition costs	107	87
Other current assets	60	68	64
Property, plant and equipment, net	14,187	14,392	14,377
Other assets	265	224	97
Other current liabilities	303	335	330
Other liabilities	281	308	317
Deferred income taxes	1,109	1,190	1,139
Accumulated deficit	(2,752)	$ (2,109)	(2,263)
Impact Of Adoption Of ACS 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	44		(32)
Contract acquisition costs	(107)		87
Other current assets	(4)		4
Property, plant and equipment, net	(56)		15
Other assets	(117)		127
Other current liabilities	(6)		5
Other liabilities	10		(9)
Deferred income taxes	(57)		51
Accumulated deficit	(184)		$ 154
Amounts Excluding Adoption of ASC 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	767
Other current assets	56
Property, plant and equipment, net	14,131
Other assets	148
Other current liabilities	297
Other liabilities	291
Deferred income taxes	1,052
Accumulated deficit	$ (2,936)

ASC 606 Adoption And Revenue _5

ASC 606 Adoption And Revenue Recognition (Schedule Of Impact Of New Accounting Pronouncement On Balance Sheet And Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 723				$ 819				$ 723	$ 819		$ 787
Contract acquisition costs	107								107			87
Prepaid expenses	86				78				86	78
Other current assets	60				64				60	64		68
Property, plant and equipment, net	14,187				14,377				14,187	14,377		14,392
Other assets	265				97				265	97		224
Other current liabilities	303				330				303	330		335
Other liabilities	281				317				281	317		308
Deferred income taxes	1,109				1,139				1,109	1,139		1,190
Accumulated deficit	(2,752)				(2,263)				(2,752)	(2,263)		$ (2,109)
Revenue	2,124	$ 2,126	$ 2,162	$ 2,199	2,217	$ 2,251	$ 2,304	$ 2,356	8,611	9,128	$ 8,896
Network access expenses									1,441	1,597	1,470
Network related expenses									1,898	1,958	1,876
Selling, general and administrative expenses									1,815	2,017	2,081
Other operating expenses									2,630
Total operating expenses									7,784
Operating income (loss)	127	$ (33)	$ 367	$ 366	(1,747)	$ 322	$ (375)	$ 317	827	(1,483)	$ 911
Impact Of Adoption Of ACS 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	44				(32)				44	(32)
Contract acquisition costs	(107)				87				(107)	87
Prepaid expenses	3								3
Other current assets	(4)				4				(4)	4
Property, plant and equipment, net	(56)				15				(56)	15
Other assets	(117)				127				(117)	127
Other current liabilities	(6)				5				(6)	5
Other liabilities	10				(9)				10	(9)
Deferred income taxes	(57)				51				(57)	51
Accumulated deficit	(184)				$ 154				(184)	$ 154
Revenue									(15)
Total operating expenses									15
Operating income (loss)									(30)
Impact Of Adoption Of ACS 606 [Member] | Accounting Standards Update 2014-09 [Member] | Restatement Adjustment [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue									(15)
Network access expenses									(3)
Selling, general and administrative expenses									19
Other operating expenses									(1)
Total operating expenses									15
Operating income (loss)									(30)
Amounts Excluding Adoption of ASC 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	767								767
Prepaid expenses	89								89
Other current assets	56								56
Property, plant and equipment, net	14,131								14,131
Other assets	148								148
Other current liabilities	297								297
Other liabilities	291								291
Deferred income taxes	1,052								1,052
Accumulated deficit	$ (2,936)								(2,936)
Revenue									8,596
Network access expenses									1,438
Network related expenses									1,898
Selling, general and administrative expenses									1,834
Other operating expenses									2,629
Total operating expenses									7,799
Operating income (loss)									$ 797

ASC 606 Adoption And Revenue _6

ASC 606 Adoption And Revenue Recognition (Disaggregation Of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 8,228	$ 8,352	$ 8,099
Subsidy and other regulatory revenue									383	776	797
Total revenue	$ 2,124	$ 2,126	$ 2,162	$ 2,199	$ 2,217	$ 2,251	$ 2,304	$ 2,356	8,611	9,128	8,896
Frontier Secure Strategic Partnerships [Member]
Disaggregation of Revenue [Line Items]
Total revenue										40	84
Data And Internet Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,878	3,862	3,693
Voice Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2,721	2,864	2,886
Video Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1,085	1,304	1,244
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									544	322	276
Consumer [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									4,380	4,476	4,383
Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,848	$ 3,876	$ 3,716
Impact Of Adoption Of ACS 606 [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(349)
Subsidy and other regulatory revenue									334
Total revenue									(15)
Impact Of Adoption Of ACS 606 [Member] | Data And Internet Services [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(103)
Impact Of Adoption Of ACS 606 [Member] | Voice Services [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(152)
Impact Of Adoption Of ACS 606 [Member] | Video Services [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									99
Impact Of Adoption Of ACS 606 [Member] | Other [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(193)
Impact Of Adoption Of ACS 606 [Member] | Consumer [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(116)
Impact Of Adoption Of ACS 606 [Member] | Commercial [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(233)
Amounts Excluding Adoption of ASC 606 [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									7,879
Subsidy and other regulatory revenue									717
Total revenue									8,596
Amounts Excluding Adoption of ASC 606 [Member] | Data And Internet Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,775
Amounts Excluding Adoption of ASC 606 [Member] | Voice Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2,569
Amounts Excluding Adoption of ASC 606 [Member] | Video Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1,184
Amounts Excluding Adoption of ASC 606 [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									351
Amounts Excluding Adoption of ASC 606 [Member] | Consumer [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									4,264
Amounts Excluding Adoption of ASC 606 [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 3,615

ASC 606 Adoption And Revenue _7

ASC 606 Adoption And Revenue Recognition (Changes In Contract Assets And Contract Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018
ASC 606 Adoption And Revenue Recognition [Abstract]
Contract assets, Beginning balance	$ 77
Revenue recognized included in opening contract balance	(57)
Credits granted, excluding amounts recognized as revenue	49
Contract assets, Ending balance	69
Contract liabilities, Beginning balance	(60)
Revenue recognized included in opening contract balance	119
Cash received, excluding amounts recognized as revenue	(135)
Other	5
Contract liabilities, Ending balance	(71)
Short-term contract assets	44	$ 40
Long-term contract assets	25	37
Short-term contract liabilities	49	41
Long-term contract liabilities	$ 22	$ 19

ASC 606 Adoption And Revenue _8

ASC 606 Adoption And Revenue Recognition (Performance Obligations, Revenue) (Details) $ in Millions	Dec. 31, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 5,173
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 2,893
Performance obligation satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue from remaining performance obligations	$ 1,209
Performance obligation satisfaction period	1 year
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	$ 487
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	$ 259
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	$ 141
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	$ 184
Performance obligation satisfaction period

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) item in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2016USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2014USD ($)	Apr. 01, 2016USD ($)item
Business Acquisition, Date of Acquisition [Abstract]
Cash paid for acquisition				$ 9,871
Capital Expenditures Integration Activities			$ 34	142
CTF Acquisition [Member]
Business Acquisition, Date of Acquisition [Abstract]
Acquisition purchase price						$ 10,540
Working Capital And Net Debt Settlement Payments Received	$ 15
Number of video connections acquired | item						1.2
Number of broadband connections acquired | item						2.1
Number of voice connections acquired | item						2.5
Capital Expenditures Integration Activities		$ 0	$ 34	$ 142
Connecticut Acquisition [Member]
Business Acquisition, Date of Acquisition [Abstract]
Cash paid for acquisition					$ 2,018

Acquisitions (Unaudited Pro For

Acquisitions (Unaudited Pro Forma Information) (Details) - CTF Acquisition [Member] $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Revenue	$ 10,255
Operating income	1,433
Net loss attributable to Frontier common shareholders	$ (262)

Acquisitions (Schedule Of Acqus

Acquisitions (Schedule Of Acqusition And Integration Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Integration costs	$ 25	$ 413
Total acquisition and integration costs	25	436
CTF Acquisition [Member]
Business Acquisition [Line Items]
Acquisition costs		23
Integration costs	$ 25	412
Connecticut Acquisition [Member]
Business Acquisition [Line Items]
Integration costs		$ 1

Accounts Receivable (Narrative)

Accounts Receivable (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Provision for uncollectible amounts	$ 93	$ 87	$ 179
Recoveries	9	39
Allowance for doubtful accounts	105	$ 69
Impact Of Adoption Of ACS 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for doubtful accounts	$ 12
Accounting Standards Update 2014-09 [Member] | Impact Of Adoption Of ACS 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for doubtful accounts				$ 32

Accounts Receivable (Accounts R

Accounts Receivable (Accounts Receivable) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Accounts Receivable [Abstract]
Retail and Wholesale	$ 745		$ 801
Other	83		87
Less: Allowance for doubtful accounts	(105)		(69)
Accounts receivable, net	$ 723	$ 787	$ 819

Accounts Receivable (Schedule O

Accounts Receivable (Schedule Of Allowance For Doubtful Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, Beginning of the Period	$ 69
Allowance for Doubtful Accounts, End of the Period	105	$ 69
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, Beginning of the Period	69	131	$ 57
Charged to Other Revenue	79	109	164
Charged (Credited) to Switched and Nonswitched Revenue and Other	14	(22)	15
Write-offs, net of Recoveries	(89)	(149)	(105)
Allowance for Doubtful Accounts, End of the Period	105	$ 69	$ 131
Impact Of Adoption Of ACS 606 [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, End of the Period	12
Restatement Adjustment [Member] | Impact Of Adoption Of ACS 606 [Member] | Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts, End of the Period	$ 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, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Capital Leased Assets, Gross		$ 152	$ 171
Proceeds from sale of property		11	102
Property subject to leasebacks		9	97
Sale leasebacks, gains		$ 9	66
Sale leaseback, deferred gain amortization period		2 years
Sale leaseback, gain recognized		$ 36	23
Sale leaseback, gain remaining		$ 16	$ 43
Subsequent Event [Member] | Towers [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sale of property	$ 76
Aggregate carrying value of the towers	$ 1

Property, Plant, And Equipment

Property, Plant, And Equipment (Property, Plant And Equipment, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 27,657		$ 26,496
Construction work in progress	436		538
Less: Accumulated depreciation	(13,470)		(12,119)
Property, plant and equipment, net	14,187	$ 14,392	14,377
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	230		231
Buildings and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 2,302		2,282
Estimated useful lives	40 years
General Support [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,616		1,570
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	$ 8,447		8,137
Central Office Electronic Circuit Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	18 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	$ 1,211		1,095
Estimated useful lives	30 years
Cable, Fiber and Wire [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 11,743		10,997
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	$ 1,672		$ 1,646
Estimated useful lives	50 years

Property, Plant, And Equipmen_2

Property, Plant, And Equipment (Schedule Of Depreciation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Depreciation [Abstract]
Depreciation expense	$ 1,385	$ 1,485	$ 1,388

Goodwill And Other Intangible_2

Goodwill And Other Intangibles (Narrative) (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
Accumulated goodwill impairment charges	$ 3,429,000,000	$ 2,788,000,000	$ 3,429,000,000	$ 2,788,000,000
Estimated future amortization expense, year 1	454,000,000		454,000,000
Estimated future amortization expense, year 2	354,000,000		354,000,000
Estimated future amortization expense, year 3	260,000,000		260,000,000
Estimated future amortization expense, year 4	173,000,000		173,000,000
Estimated future amortization expense, year 5	95,000,000		95,000,000
Goodwill impairment	$ 641,000,000	$ 2,078,000,000	641,000,000	$ 2,748,000,000
Infinite-lived intangible impairment			$ 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]
Goodwill, input	5.3	5.5	5.3	5.5	5.5	5.5	5.5	5.8
Measurement Input, EBITDA Multiple [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill, input	4.4		4.4
Measurement Input, EBITDA Multiple [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill, input	6.5		6.5
Customer Base [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension			5 years 3 months 15 days
Royalty Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Weighted-Average Period before Renewal or Extension			2 years 3 months

Goodwill And Other Intangible_3

Goodwill And Other Intangibles (Schedule Of Goodwill Activity) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Goodwill And Other Intangibles [Abstract]
Goodwill, Beginning Balance			$ 7,024	$ 9,674
Goodwill impairment	$ (641)	$ (2,078)	(641)	(2,748)
CTF Acquistion adjustment				98
Goodwill, Ending Balance	$ 6,383	$ 7,024	$ 6,383	$ 7,024

Goodwill And Other Intangible_4

Goodwill And Other Intangibles (Components Of Other Intangibles) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Intangible Assets [Line Items]
Gross Carrying Amount, Total	$ 5,382	$ 5,382
Accumulated Amortization	(3,888)	(3,319)
Net Carrying Amount	1,494	2,063
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	5,188	5,188
Accumulated Amortization	(3,848)	(3,294)
Net Carrying Amount	1,340	1,894
Royalty Agreement [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite	72	72
Accumulated Amortization	(40)	(25)
Net Carrying Amount	$ 32	$ 47

Goodwill And Other Intangible_5

Goodwill And Other Intangibles (Schedule Of Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Other Intangibles [Abstract]
Amortization expense	$ 569	$ 699	$ 643

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)	Oct. 01, 2018	Jul. 03, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jul. 03, 2018	Mar. 19, 2018	Jun. 15, 2017
Debt Instrument [Line Items]
Payment to retire debt instruments			$ 2,828,000,000
Loss on early extinguishment of debt			32,000,000	$ (88,000,000)	$ (7,000,000)
Gain on extinguishment of debt			32,000,000
Financing obligation for contributions of real property to pension plan			37,000,000		15,000,000
Pension Building Contribution Aggregate Annual Rent			$ 5,000,000		$ 2,000,000
Lease term of contributed property			20 years		15 years
Gain (loss) on contribution of property to defined benefit					$ 0
Capital Lease Term, minimum years			1 year
Capital Lease Term, maximum years			7 years
Proceeds from long-term debt borrowings			$ 1,840,000,000	1,500,000,000	1,940,000,000
Remaining outstanding principal			17,400,000,000	$ 17,863,000,000
Sale leaseback transaction			37,000,000		15,000,000
2016 Pension Real Estate Contributions [Member]
Debt Instrument [Line Items]
Financing obligation for contributions of real property to pension plan					15,000,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, current borrowings			71,000,000
Senior Note Due 11/1/2025 [Member] | Exchangeable Debt [Member]
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Amount					$ 188,000,000
Interest Rate					10.50%
Senior Note Due 4/15/2020 [Member] | Exchangeable Debt [Member]
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Amount					$ 147,000,000
Interest Rate					8.50%
Senior Note Due 9/15/2020 [Member] | Exchangeable Debt [Member]
Debt Instrument [Line Items]
Debt Conversion, Converted Instrument, Amount					$ 66,000,000
Interest Rate					8.875%
Term Loan Due 06/15/2024 [Member]
Debt Instrument [Line Items]
Proceeds from long-term debt borrowings		$ 240,000,000	240,000,000
Senior Note Due 4/15/2017 [Member] | Exchangeable Debt [Member]
Debt Instrument [Line Items]
Debt Conversion, Original Debt, Amount					$ 397,000,000
Interest Rate					8.25%
CTF Acquisition [Member]
Debt Instrument [Line Items]
Long Term Debt Assumed					$ 600,000,000
CTF Acquisition [Member] | Subsidiary Senior Note Due 11/15/2031 [Member]
Debt Instrument [Line Items]
Interest Rate					8.50%
Long Term Debt Assumed					$ 100,000,000
CTF Acquisition [Member] | Subsidiary Senior Note Due 05/15/2027 [Member]
Debt Instrument [Line Items]
Interest Rate					6.75%
Long Term Debt Assumed					$ 200,000,000
CTF Acquisition [Member] | Subsidiary Senior Note Due 2/1/2028 [Member]
Debt Instrument [Line Items]
Interest Rate					6.86%
Long Term Debt Assumed					$ 300,000,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Payments to retire debt			117,000,000
Remaining outstanding principal			$ 500,000,000
Senior 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
Payments to retire debt				$ 10,000,000
Senior Unsecured Debt [Member] | Senior Note Due 10/1/2018 [Member]
Debt Instrument [Line Items]
Interest Rate				8.125%
Debt instrument, maturity date			Oct. 1, 2018
Payments to retire debt				$ 92,000,000
Senior 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
Payments to retire debt				$ 550,000,000
Senior 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
Payments to retire debt				$ 763,000,000
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, 2019
Payments to retire debt				$ 30,000,000
Senior Unsecured Debt [Member] | Senior Note Due 4/15/2017 [Member]
Debt Instrument [Line Items]
Interest Rate				8.25%
Payments to retire debt				$ 210,000,000
Secured Debt [Member]
Debt Instrument [Line Items]
Payment to retire debt instruments			$ 828,000,000
Remaining outstanding principal			5,246,000,000	$ 3,511,000,000
Secured Debt [Member] | Second Lien Notes Due 4/1/2026 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 1,600,000,000				$ 1,600,000,000
Interest Rate			8.50%				8.50%
Debt instrument, maturity date			Apr. 1, 2026
Remaining outstanding principal			$ 1,600,000,000
Secured Debt [Member] | Term Loan Due 06/15/2024 [Member]
Debt Instrument [Line Items]
Interest Rate			6.28%	5.32%
Debt instrument, maturity date			Jun. 15, 2024
Remaining outstanding principal			$ 1,716,000,000	$ 1,492,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Remaining outstanding principal			$ 11,297,000,000	$ 13,495,000,000
Unsecured Debt [Member] | Senior Note Due 7/1/2021 [Member]
Debt Instrument [Line Items]
Interest Rate			9.25%	9.25%
Debt instrument, maturity date			Jul. 1, 2021
Payment to retire debt instruments			$ 400,000,000
Remaining outstanding principal			$ 89,000,000	$ 490,000,000
Unsecured Debt [Member] | Senior Note Due 9/15/2021 [Member]
Debt Instrument [Line Items]
Interest Rate			6.25%	6.25%
Debt instrument, maturity date			Sep. 15, 2021
Payment to retire debt instruments			$ 555,000,000
Remaining outstanding principal			$ 220,000,000	$ 775,000,000
Unsecured Debt [Member] | Senior Note Due 4/15/2022 [Member]
Debt Instrument [Line Items]
Interest Rate			8.75%	8.75%
Debt instrument, maturity date			Apr. 15, 2022
Remaining outstanding principal			$ 500,000,000	$ 500,000,000
Unsecured Debt [Member] | Senior Note Due 9/15/2022 [Member]
Debt Instrument [Line Items]
Interest Rate			10.50%	10.50%
Debt instrument, maturity date			Sep. 15, 2022
Remaining outstanding principal			$ 2,188,000,000	$ 2,188,000,000
Unsecured Debt [Member] | Senior Note Due 1/15/2023 [Member]
Debt Instrument [Line Items]
Interest Rate			7.125%	7.125%
Debt instrument, maturity date			Jan. 15, 2023
Remaining outstanding principal			$ 850,000,000	$ 850,000,000
Unsecured Debt [Member] | Senior Note Due 4/15/2024 [Member]
Debt Instrument [Line Items]
Interest Rate			7.625%	7.625%
Debt instrument, maturity date			Apr. 15, 2024
Remaining outstanding principal			$ 750,000,000	$ 750,000,000
Unsecured Debt [Member] | Senior Note Due 1/15/2025 [Member]
Debt Instrument [Line Items]
Interest Rate			6.875%	6.875%
Debt instrument, maturity date			Jan. 15, 2025
Remaining outstanding principal			$ 775,000,000	$ 775,000,000
Unsecured Debt [Member] | Senior Note Due 11/1/2025 [Member]
Debt Instrument [Line Items]
Interest Rate			7.00%	7.00%
Debt instrument, maturity date			Nov. 1, 2025
Remaining outstanding principal			$ 138,000,000	$ 138,000,000
Unsecured Debt [Member] | Senior Note Due 8/15/2031 [Member]
Debt Instrument [Line Items]
Interest Rate			9.00%	9.00%
Debt instrument, maturity date			Aug. 15, 2031
Remaining outstanding principal			$ 945,000,000	$ 945,000,000
Unsecured Debt [Member] | Debentures Due 10/1/2034 [Member]
Debt Instrument [Line Items]
Interest Rate			7.68%	7.68%
Debt instrument, maturity date			Oct. 1, 2034
Remaining outstanding principal			$ 1,000,000	$ 1,000,000
Unsecured Debt [Member] | Senior Notes Due 10/1/2018 [Member]
Debt Instrument [Line Items]
Interest Rate			8.125%	8.125%
Debt instrument, maturity date			Oct. 1, 2018
Payments to retire debt			$ 61,000,000
Payment to retire debt instruments	$ 431,000,000
Remaining outstanding principal				$ 491,000,000
Unsecured Debt [Member] | Senior Note Due 4/15/2020 [Member]
Debt Instrument [Line Items]
Interest Rate			8.50%	8.50%
Debt instrument, maturity date			Apr. 15, 2020
Repurchase of senior notes			$ 447,000,000
Remaining outstanding principal			$ 172,000,000	$ 619,000,000
Unsecured Debt [Member] | Senior Note Due 9/15/2020 [Member]
Debt Instrument [Line Items]
Interest Rate			8.875%	8.875%
Debt instrument, maturity date			Sep. 15, 2020
Payment to retire debt instruments			$ 249,000,000
Remaining outstanding principal			$ 55,000,000	$ 303,000,000
Unsecured Debt [Member] | Senior Note Due 3/15/2019 [Member]
Debt Instrument [Line Items]
Interest Rate			7.125%	7.125%
Debt instrument, maturity date			Mar. 15, 2019
Payments to retire debt			$ 56,000,000
Remaining outstanding principal			348,000,000	$ 404,000,000
Unsecured Debt Excluding Open Market Purchases [Member]
Debt Instrument [Line Items]
Payment to retire debt instruments			1,651,000,000
JP Morgan Term Loan A [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 1,625,000,000
Debt instrument, maturity date			Mar. 31, 2021
JP Morgan Term Loan A [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Effective basis spread			2.75%
JP Morgan Term Loan B [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 1,740,000,000					$ 1,500,000,000
Debt instrument, maturity date			Jun. 15, 2024
JP Morgan Term Loan B [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest Rate Margin			2.75%
JP Morgan Term Loan B [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest Rate Margin			3.75%
JP Morgan Revolving Credit Facility 2015 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date			Feb. 27, 2022
Line of credit facility maximum borrowing capacity			$ 850,000,000
Line of credit facility, current borrowings			$ 275,000,000
JP Morgan Combined Credit Facility [Member]
Debt Instrument [Line Items]
Days Prior To Maturity To Meet Threshold To Not Accelerate Debt			91 days
Maximum Debt Threshold To Not Accelerate Debt			$ 500,000,000
Debt Instrument, Acceleration Cause			The maturities of the Term Loan A, the Revolver, and the Term Loan B, in each case if still outstanding, will be accelerated in the following circumstances: (i) if, 91 days before the maturity date of any series of Senior Notes maturing in 2020, 2023 and 2024, more than $500 million in principal amount remains outstanding on such series; or (ii) if, 91 days before the maturity date of the first series of Senior Notes maturing in 2021 or 2022, more than $500 million in principal amount remains outstanding, in the aggregate, on the two series of Senior Notes maturing in such year. . As of December 31, 2018, less than $500 million in principal amount remains outstanding on the senior notes due 2020 and on the two series of senior notes maturing in 2021.
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
COBANK Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest Rate Margin			4.875%
Minimum [Member] | JP Morgan Term Loan A And Revolver [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest Rate Margin			0.75%
Minimum [Member] | JP Morgan Term Loan A And Revolver [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest Rate Margin			1.75%
Minimum [Member] | COBANK Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest Rate Margin			0.875%
Minimum [Member] | COBANK Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest Rate Margin			1.875%
Maximum [Member] | JP Morgan Term Loan A And Revolver [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest Rate Margin			1.75%
Maximum [Member] | JP Morgan Term Loan A And Revolver [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest Rate Margin			2.75%
Maximum [Member] | COBANK Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest Rate Margin			3.875%
Maximum [Member] | COBANK Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest Rate Margin			4.875%

Long-Term Debt (Long-Term Debt)

Long-Term Debt (Long-Term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 17,863
Payments and Retirements	(2,828)
New Borrowings	2,365
Long-term debt, ending balance	17,863	$ 17,400	$ 17,863
Less: Debt Issuance Costs		(178)	(183)
Less: Debt Premium/(Discount)		50	54
Less: Current Portion		(814)	(656)
Total Long-Term Debt		$ 16,358	16,970
Interest Rate		8.59%
Secured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	3,511
Payments and Retirements	(828)
Long-term debt, ending balance	3,511	$ 5,246	3,511
Secured Debt [Member] | Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	3,511
Payments and Retirements	(630)
New Borrowings	2,365
Long-term debt, ending balance	3,511	$ 5,246	3,511
Interest Rate		6.76%
Secured Debt [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	107
Long-term debt, ending balance	107	$ 107	107
Interest Rate		8.35%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	13,495
Long-term debt, ending balance	13,495	$ 11,297	13,495
Unsecured Debt [Member] | Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	13,495
Payments and Retirements	(2,198)
Long-term debt, ending balance	13,495	$ 11,297	13,495
Interest Rate		9.56%
Unsecured Debt [Member] | Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term debt, beginning balance	750
Long-term debt, ending balance	$ 750	$ 750	$ 750
Interest Rate		6.90%

Long-Term Debt (Schedule Of Uns

Long-Term Debt (Schedule Of Unsecured Debt) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Mar. 19, 2018
Debt Instrument [Line Items]
Principal Outstanding	$ 17,400	$ 17,863
Secured Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 5,246	3,511
Secured Debt [Member] | Term Loan Due 10/24/2019 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Oct. 24, 2019
Principal Outstanding		$ 245
Interest Rate		5.445%
Secured Debt [Member] | Term Loan Due 3/31/20121 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Mar. 31, 2021
Principal Outstanding	$ 1,402	$ 1,483
Interest Rate	5.28%	4.32%
Secured Debt [Member] | Term Loan Due 10/12/20121 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Oct. 12, 2021
Principal Outstanding	$ 239	$ 276
Interest Rate	7.405%	5.445%
Secured Debt [Member] | Revolver Due 2/27/2022 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Feb. 27, 2022
Principal Outstanding	$ 275
Interest Rate	5.28%
Secured Debt [Member] | Term Loan Due 06/15/2024 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jun. 15, 2024
Principal Outstanding	$ 1,716	$ 1,492
Interest Rate	6.28%	5.32%
Secured Debt [Member] | Second Lien Notes Due 4/1/2026 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Apr. 1, 2026
Principal Outstanding	$ 1,600
Interest Rate	8.50%		8.50%
Secured Debt [Member] | IDRB due 5/1/2030 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	May 1, 2030
Principal Outstanding	$ 13	$ 13
Interest Rate	6.20%	6.20%
Secured Debt [Member] | Equipment Financings [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 1	$ 2
Interest Rate	0.00%	0.00%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 11,297	$ 13,495
Unsecured Debt [Member] | Senior Notes Due 10/1/2018 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Oct. 1, 2018
Principal Outstanding		$ 491
Interest Rate	8.125%	8.125%
Unsecured Debt [Member] | Senior Note Due 3/15/2019 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Mar. 15, 2019
Principal Outstanding	$ 348	$ 404
Interest Rate	7.125%	7.125%
Unsecured Debt [Member] | Senior Note Due 4/15/2020 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Apr. 15, 2020
Principal Outstanding	$ 172	$ 619
Interest Rate	8.50%	8.50%
Unsecured Debt [Member] | Senior Note Due 9/15/2020 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Sep. 15, 2020
Principal Outstanding	$ 55	$ 303
Interest Rate	8.875%	8.875%
Unsecured Debt [Member] | Senior Note Due 7/1/2021 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jul. 1, 2021
Principal Outstanding	$ 89	$ 490
Interest Rate	9.25%	9.25%
Unsecured Debt [Member] | Senior Note Due 9/15/2021 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Sep. 15, 2021
Principal Outstanding	$ 220	$ 775
Interest Rate	6.25%	6.25%
Unsecured Debt [Member] | Senior Note Due 4/15/2022 [Member]
Debt Instrument [Line Items]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, maturity date	Sep. 15, 2025
Principal Outstanding	$ 3,600	$ 3,600
Interest Rate	11.00%	11.00%
Unsecured Debt [Member] | Senior Note Due 11/1/2025 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Nov. 1, 2025
Principal Outstanding	$ 138	$ 138
Interest Rate	7.00%	7.00%
Unsecured Debt [Member] | Senior Note Due 8/15/2026 [Member]
Debt Instrument [Line Items]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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	$ 107	$ 107
Secured Subsidiary Debt [Member] | Debentures Due 11/15/2031 [Member]
Debt Instrument [Line Items]
Debt instrument, 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]
Debt instrument, maturity date	Jan. 3, 2028
Principal Outstanding	$ 7	$ 7
Interest Rate	6.154%	6.152%
Unsecured Subsidiary Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 750	$ 750
Unsecured Subsidiary Debt [Member] | Senior Secured Debt Due 3/31/2021
Debt Instrument [Line Items]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, 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]
Debt instrument, maturity date	Oct. 15, 2029
Principal Outstanding	$ 50	$ 50
Interest Rate	8.40%	8.40%
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 500
Senior Unsecured Debt [Member] | Senior Note Due 3/15/2019 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date		Mar. 15, 2019
Interest Rate		7.125%
Senior Unsecured Debt [Member] | Senior Note Due 4/15/2020 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date		Apr. 15, 2020
Interest Rate		8.50%
Senior Unsecured Debt [Member] | Senior Note Due 9/15/2020 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date		Sep. 15, 2020
Interest Rate		8.875%
Senior Unsecured Debt [Member] | Senior Note Due 7/1/2021 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date		Jul. 1, 2021
Interest Rate		9.25%
Senior Secured Debt, Senior Unsecured Debt And Subsidiary Debentures [Member]
Debt Instrument [Line Items]
Principal Outstanding	$ 17,400	$ 17,863
JP Morgan Term Loan A [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Mar. 31, 2021
JP Morgan Term Loan B [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jun. 15, 2024

Long-Term Debt (Debt Maturities

Long-Term Debt (Debt Maturities By Year) (Details) $ in Millions	Dec. 31, 2018USD ($)
Long-Term Debt [Abstract]
Principal Payments 2019	$ 539
Principal Payments 2020	437
Principal Payments 2021	1,604
Principal Payments 2022	2,706
Principal Payments 2023	868
Principal Payments Thereafter	$ 10,971

Long-Term Debt (Schedule Of Fut

Long-Term Debt (Schedule Of Future Minimum Lease Obligations) (Details) $ in Millions	Dec. 31, 2018USD ($)
Finance Lease Obligations, Future Minimum Payments [Abstract]
2,019	$ 13
2,020	14
2,021	14
2,022	14
2,023	15
Thereafter	117
Total future payments	187
Less: Amounts representing interest	(109)
Present value of minimum lease payments	78
Capital Lease Obligations, Future Minimum Payments [Abstract]
2,019	30
2,020	19
2,021	13
2,022	8
2,023	10
Thereafter	4
Total future payments	84
Less: Amounts representing interest	(15)
Present value of minimum lease payments	$ 69

Restructuring And Other Charg_3

Restructuring And Other Charges (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring And Other Charges [Abstract]
Restructuring Reserve	$ 18	$ 25	$ 47
Severance Costs	12	68
Defined Benefit Plan, Special termination Benefits cost		5	26
Loss on sale of business		9
Restructuring Charges	35	$ 82	$ 91
Transformation costs	$ 23

Restructuring And Other Charg_4

Restructuring And Other Charges (Changes In Restructuring Reserve) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring And Other Charges [Abstract]
Restructuring Reserve, Beginning Balance	$ 25	$ 47
Severance costs	12	68
Transformation costs	23
Cash payments during the period	(42)	(90)
Restructuring Reserve, Ending Balance	$ 18	$ 25

Investment And Other Income, _3

Investment And Other Income, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investment And Other Income, Net [Abstract]
Interest and dividend income	$ 6	$ 6	$ 13
Pension and OPEB benefit (Costs)	10	(2)	(23)
Gain on expiration/settlement of customer advances			13
All other, net	(3)	(3)	1
Total investment and other income, net	$ 13	$ 1	$ 4

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, 2017	Dec. 31, 2016	Jul. 10, 2017	Dec. 31, 2015	Jun. 30, 2015
Class of Stock [Line Items]
Common stock, Shares authorized				175,000,000	175,000,000		175,000,000
Common stock, Shares issued				106,025,000	79,352,000		80,000,000
Common stock, Shares outstanding				105,536,000	78,441,000		79,000,000
Common stock, par value (in dollars per share)				$ 0.25	$ 0.25
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 1,866
Preferred dividends	$ 54			$ 107	$ 214	$ 214
Class of stock conversion, rate		1.3333
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, Shares authorized				50,000,000	50,000,000				19,250,000
Preferred stock, Shares issued				0	19,250,000
Preferred stock, Shares outstanding				0	19,250,000
Shares Issued, Price Per Share									$ 100
Preferred Stock, Dividend Rate, Percentage				11.125%	11.125%
Preferred Stock, Par or Stated Value Per Share				$ 0.01	$ 0.01
Common Stock [Member]
Class of Stock [Line Items]
Common stock, Shares outstanding				106,025,000	79,532,000	79,532,000		79,532,000
Shares issued in stock conversion		25,529,000		25,529,000

Stock Plans (Narrative) (Detail

Stock Plans (Narrative) (Details) $ in Millions	Feb. 14, 2018shares	Feb. 16, 2017shares	Feb. 11, 2016shares	Dec. 31, 2018USD ($)ShareBasedCompensationPlanentityshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plan under which grants were made | ShareBasedCompensationPlan				7
Number of stock-based compensation plan under which grants were not made | ShareBasedCompensationPlan				6
2017 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Plan authorization period				10 years
EIP Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for grant under the plans (in shares) | shares				5,667,000
Shares available for grant under the plan (in shares) | shares				2,607,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized during the period | $				$ 5	$ 1	$ 6
Shares granted (in shares) | shares	284,000	157,400	111,000	284,000	211,000	111,000
Performance Shares
Initial period over which target number of performance shares are awarded				90 days
Measurement period				3 years
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized during the period | $				$ 13	$ 18	$ 18
Shares granted (in shares) | shares				2,023,000	454,000	396,000
Restricted Stock
Remaining unrecognized compensation cost associated with unvested restricted stock awards | $				$ 24
Weighted average period over which unvested restricted stock awards unrecognized compensation cost is expected to be recognized (in years)				1 year 3 months 18 days
Stock Options [Member] | 2017 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Non-Employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized during the period | $				$ (1)	$ (5)	$ 0
Non Employee Directors Compensation Plans
Plan units earned during the period (in shares) | shares				183,791	94,034	29,618
Number of directors participating in the plan during the period | entity				9
Cash compensation | $				$ 1	$ 1	$ 1

Stock Plans (LTIP Target Perfor

Stock Plans (LTIP Target Performance Shares) (Details) - Performance Shares [Member] - shares	Feb. 14, 2018	Feb. 16, 2017	Feb. 11, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of period (in shares)				306,000	190,000	168,000
LTIP target performance shares granted	284,000	157,400	111,000	284,000	211,000	111,000
LTIP target performance shares earned				(18,000)	(41,000)	(59,000)
LTIP target performance shares forfeited				(75,000)	(54,000)	(30,000)
Balance at end of period (in shares)				497,000	306,000	190,000

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of period (in shares)	633	549	462
Shares granted (in shares)	2,023	454	396
Shares earned (in shares)	(221)	(240)	(248)
Shares forfeited (in shares)	(577)	(130)	(61)
Balance at end of period (in shares)	1,858	633	549
Balance at beginning of period (in dollars per shares)	$ 58.63	$ 78	$ 88.95
Restricted stock granted (in dollars per shares)	8.26	47.77	65.40
Restricted stock vested (in dollars per shares)	66.82	80.86	78.90
Restricted stock forfeited (in dollars per shares)	16.47	60.92	76.65
Balance at end of period (in dollars per shares)	$ 16.02	$ 58.63	$ 78
Balance at beginning of period	$ 4	$ 28	$ 33
Restricted stock granted	5	3	20
Restricted stock vested	1	2	13
Balance at end of period	$ 4	$ 4	$ 28

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount	$ 72	$ 608
Federal rate	21.00%	35.00%	35.00%
Adjustment of deferred tax balances			$ 36
Domestic production activities deduction			12
Federal research and development credits			6
Deferred Tax Assets, Valuation Allowance	$ 497	$ 407
Effect of expiration of statute of limitations during next twelve months	0
Gross tax liability for tax positions that may not be sustained under a more likely than not threshold	11
Accrued interest on tax liability	0	1
Deferred Tax Assets, Net, Current	1.5
Noncurrent deferred tax assets, net		1.5
Proceeds from Income Tax Refunds		51
Income tax benefit	5	$ 1	$ (45)
Income taxes paid	4
Tax deductible goodwill	1,952
Research Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	19
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Amount	35
Operating loss carryforward	9,400
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	2,400
Impact Of Adoption Of ACS 606 [Member] | Accounting Standards Update 2014-09 [Member]
Income Tax Contingency [Line Items]
Income tax benefit	$ 7

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Provision For Income Taxes) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Consolidated tax provision at federal statutory rate	21.00%	35.00%	35.00%
State income tax provisions, net of federal income tax benefit	1.60%	1.70%	(0.10%)
Tax reserve adjustment	0.10%	0.10%	0.60%
Domestic production activities deduction			(1.90%)
Changes in certain deferred tax balances	(3.50%)	(0.40%)	5.80%
Goodwill impairment	(10.40%)	(19.10%)
Share-based payments	0.50%
Federal research and development credit	0.10%	0.10%	1.00%
Deferred Tax Remeasurement - 2017 Tax Reform	0.60%	26.10%
All other, net	(0.20%)	(0.10%)	(0.20%)
Effective tax rate	8.80%	43.40%	40.20%

Income Taxes (Components Of Net

Income Taxes (Components Of Net Deferred Income Tax Liability (Asset) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax liabilities [Abstract]
Property, plant and equipment basis differences	$ 2,182	$ 2,022
Intangibles	18	140
Deferred revenue/expense	66	8
Other, net		4
Gross deferred income tax liability	2,266	2,174
Deferred income tax assets [Abstract]
Pension liability	209	176
Tax operating loss carryforward	1,027	960
Employee benefits	176	192
Interest expense deduction limitation carryforward	104
Accrued expenses	41	23
Lease obligations	33	39
Tax credits	37	43
Allowance for doubtful accounts	26	7
Other, net	1	2
Gross deferred income tax asset	1,654	1,442
Less: Valuation allowance	(497)	(407)
Net deferred income tax asset	1,157	1,035
Net deferred income tax liability	$ 1,109	$ 1,139

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current [Abstract]
Federal	$ (1)	$ (4)	$ (52)
State	6	5	7
Total Current	5	1	(45)
Deferred [Abstract]
Federal	(77)	(1,312)	(145)
State	10	(72)	(60)
Total Deferred	(67)	(1,384)	(205)
Total income tax benefit	(62)	(1,383)	(250)
Income taxes charged (credited) to equity of Frontier [Abstract]
Utilization of the benefits arising from restricted stock		(1)	(5)
Deferred income taxes (benefits) arising from the recognition of additional pension/OPEB liability	(31)	7	(21)
Total income taxes charged (credited) to equity of Frontier	(31)	6	(26)
Total income tax beneift	$ (93)	$ (1,377)	$ (276)

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, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Unrecognized tax benefits - beginning of year	$ 12	$ 16
Gross increases - current year tax positions		3
Gross decreases - FIN 48 liability release		(7)
Gross decreases - expired statute of limitations	(1)
Unrecognized tax benefits - end of year	$ 11	$ 12

Net Loss Per Common Share (Narr

Net Loss Per Common Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
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)	1,334	1,334	2,667
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)	348,093	203,952	125,431
Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)		19,250,000

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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Loss Per Common Share [Abstract]
Net loss attributable to Frontier common shareholders	$ (219)	$ (426)	$ (72)	$ (33)	$ (1,082)	$ (92)	$ (715)	$ (129)	$ (750)	$ (2,018)	$ (587)
Less: Dividends paid on unvested restricted stock awards										(2)	(3)
Total basic net loss attributable to Frontier common shareholders									(750)	(2,020)	(590)
Effect of loss related to dilutive stock units
Total diluted net loss attributable to Frontier common shareholders									$ (750)	$ (2,020)	$ (590)
Total weighted average shares and unvested restricted stock awards outstanding - basic (in shares)									91,523	78,409	78,142
Less: Weighted average unvested restricted stock awards									(1,840)	(673)	(535)
Total weighted average shares outstanding - basic									89,683	77,736	77,607
Basic net loss per share attributable to Frontier common shareholders	$ (2.12)	$ (4.11)	$ (0.92)	$ (0.44)	$ (13.91)	$ (1.19)	$ (9.20)	$ (1.67)	$ (8.37)	$ (25.99)	$ (7.61)
Total weighted average shares outstanding - diluted									89,683	77,736	77,607
Diluted net loss per share attributable to Frontier common shareholders	$ (2.12)	$ (4.11)	$ (0.92)	$ (0.44)	$ (13.91)	$ (1.19)	$ (9.21)	$ (1.67)	$ (8.37)	$ (25.99)	$ (7.61)

Comprehensive Loss (Narrative)

Comprehensive Loss (Narrative) (Details) - Pension Benefits [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 01, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Discount rate - used at year end to value obligation (in hundredths)	4.30%	3.70%	4.10%	4.00%	4.50%
Other comprehensive income (loss) before reclassifications			$ 105
Pension Settlement Cost [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassifications, pretax	$ (41)	$ (83)
Reclassifications, net of tax	$ (31)	$ 51

Comprehensive Loss (Accumulated

Comprehensive Loss (Accumulated Other Comprehensive Loss, Net Of Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	$ 2,274	$ 4,519	$ 5,614
Net current-period other comprehensive income (loss)	(97)	21	(34)
Balance, ending	1,600	2,274	4,519
Deferred Taxes On Pension And OPEB Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Deferred tax items	250	223	231	$ 211
Defined Benefit Plans [Member] | Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(345)	(403)	(363)
Other comprehensive income (loss) before reclassifications	(191)	(12)	(65)
Amounts reclassified from accumulated other comprehensive income (loss)	47	70	25
Net current-period other comprehensive income (loss)	(144)	58	(40)
Balance, ending	(489)	(345)	(403)
Defined Benefit Plans [Member] | Postretirement Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(21)	16	10
Other comprehensive income (loss) before reclassifications	51	(31)	11
Amounts reclassified from accumulated other comprehensive income (loss)	(4)	(6)	(5)
Net current-period other comprehensive income (loss)	47	(37)	6
Balance, ending	26	(21)	16
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning	(366)	(387)	(353)
Other comprehensive income (loss) before reclassifications	(140)	(43)	(54)
Amounts reclassified from accumulated other comprehensive income (loss)	43	64	20
Net current-period other comprehensive income (loss)	(97)	21	(34)
Balance, ending	$ (463)	$ (366)	$ (387)

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member] | Amortization Of Defined Benefit Cost Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	$ (65)	$ (113)	$ (40)
Tax impact	18	43	15
Reclassifications, net of tax	(47)	(70)	(25)
Pension Benefits [Member] | Actuarial Gains (Losses) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	(24)	(30)	(40)
Pension Benefits [Member] | Pension Settlement Cost [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	(41)	(83)
Reclassifications, net of tax	(31)	51
Postretirement Costs [Member] | Amortization Of Defined Benefit Cost Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	6	9	8
Tax impact	(2)	(3)	(3)
Reclassifications, net of tax	4	6	5
Postretirement Costs [Member] | Prior-Service Credits (Costs) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	9	$ 9	9
Postretirement Costs [Member] | Actuarial Gains (Losses) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, pretax	$ (3)		$ (1)

Segment Information (Details)

Segment Information (Details)	12 Months Ended
	Dec. 31, 2018segment
Segment Information [Abstract]
Number of operating regions	1
Number of reportable segments	1

Quarterly Financial Data (Narra

Quarterly Financial Data (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Line Items]
Goodwill, Impairment Loss	$ 641	$ 2,078	$ 641	$ 2,748
Goodwill, Impairment Loss, Net of Tax	$ 572	$ 1,822
Investment and other income, net			13	1	$ 4
Pension settlement costs			$ 41	83
Restatement Adjustment [Member] | Accounting Standards Update 2017-07 [Member]
Quarterly Financial Data [Line Items]
Investment and other income, net				(2)	$ (23)
Pension settlement costs				$ 83

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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Revenue	$ 2,124	$ 2,126	$ 2,162	$ 2,199	$ 2,217	$ 2,251	$ 2,304	$ 2,356	$ 8,611	$ 9,128	$ 8,896
Operating income (loss)	127	(33)	367	366	(1,747)	322	(375)	317	827	(1,483)	911
Net loss attributable to Frontier common shareholders	$ (219)	$ (426)	$ (72)	$ (33)	$ (1,082)	$ (92)	$ (715)	$ (129)	$ (750)	$ (2,018)	$ (587)
Basic net loss per share attributable to Frontier common shareholders	$ (2.12)	$ (4.11)	$ (0.92)	$ (0.44)	$ (13.91)	$ (1.19)	$ (9.20)	$ (1.67)	$ (8.37)	$ (25.99)	$ (7.61)
Diluted net loss per share attributable to Frontier common shareholders	$ (2.12)	$ (4.11)	$ (0.92)	$ (0.44)	$ (13.91)	$ (1.19)	$ (9.21)	$ (1.67)	$ (8.37)	$ (25.99)	$ (7.61)

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 01, 2016	Dec. 31, 2015
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	$ 26	$ 26	$ 25
Contribution of Property	$ 37		$ 15
Defined Benefit Plan, Lease term of contributed property	20 years		15 years
Decrease in pension assets	$ 326
Percentage of decrease in pension plan	12.00%
Accumulated benefit obligation	$ 3,106	3,268
401(k) savings plan employer contributions	45	48	$ 48
Plan assets	2,348	$ 2,674
Benefit payments	317
Investment returns	$ 159
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)	4.30%	3.70%	4.10%	4.00%	4.50%
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 Hundreths	7.50%
Expected amortization of unrecognized loss	$ 57
Defined Benefit Plan, Settlements, Benefit Obligation	254	$ 486
Defined Benefit Plan, Settlements Benefit obligation threshold	216
Pension settlement costs	41	83
Contribution of Property	37
Contributions to plans	150	206	$ 28
Contributions to plan, net of differential		75
Employer cash contributions	$ 113		13
Defined Benefit Plan, Funded Percentage	74.00%
Differential Payment Received		131
Plan contributions required, 2018	150
Plan assets	2,348	2,674	2,766
Benefit payments	63	59
Investment returns	159	(378)
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected amortization of prior service credit	9
Expected amortization of unrecognized loss	3
Contributions to plans	$ 31	24
Annual rate of increase in the per-capita cost of covered medical benefits (in hundredths)	6.50%
Annual rate of increase in the per-capita cost of covered medical benefits in 2024 (in hundredths)	5.00%
Effect on total of service and interest cost components, 1 percentage point increase	$ 1
Effect on postretirement benefit obligation, 1 percentage point increase	19
Effect on total of service and interest cost components, 1 percentage point decrease	(1)
Effect on postretirement benefit obligation, 1 percentage point decrease	(19)
Plan assets
Benefit payments	$ 38	$ 31
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)	4.30%	3.70%	4.10%
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)	4.40%	3.80%	4.30%
2016 Pension Real Estate Contributions [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution of Property			$ 15
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation	40.00%
Equity Securties [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation	60.00%

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	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in projected benefit obligation (PBO) [Roll Forward]
Benefits paid	$ (317)
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	2,674
Actual return on plan assets	(159)
Fair value of plan assets at end of year	2,348	$ 2,674
Amounts recognized in the consolidated balance sheet [Abstract]
Pension and other postretirement benefits - current	(39)	(29)
Pension and other postretirement benefits - noncurrent	(1,750)	(1,676)
Pension Benefits [Member]
Change in projected benefit obligation (PBO) [Roll Forward]
PBO at beginning of year	3,363	3,465
Service cost	90	97	$ 88
Interest cost	125	127	122
Actuarial (gain) loss	(88)	214
Benefits paid	(63)	(59)
Settlements	(254)	(486)
Special termination benefits		5
PBO at end of year	3,173	3,363	3,465
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	2,674	2,766
Actual return on plan assets	(159)	378
Employer contributions	150	206	28
Settlements	(254)	(486)
Differential payment received from Verizon		(131)
Benefits paid	(63)	(59)
Fair value of plan assets at end of year	2,348	2,674	2,766
Funded status	(825)	(689)
Amounts recognized in the consolidated balance sheet [Abstract]
Pension and other postretirement benefits - noncurrent	(825)	(689)
Accumulated other comprehensive (gain) loss	754	556	647
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Change in projected benefit obligation (PBO) [Roll Forward]
PBO at beginning of year	1,016	925
Service cost	21	21	19
Interest cost	38	40	37
Plan participants' contributions	7	7
Actuarial (gain) loss	(79)	54
Benefits paid	(38)	(31)
PBO at end of year	965	1,016	925
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year
Plan participants' contributions	7	7
Employer contributions	31	24
Benefits paid	(38)	(31)
Fair value of plan assets at end of year
Funded status	(965)	(1,016)
Amounts recognized in the consolidated balance sheet [Abstract]
Pension and other postretirement benefits - current	(39)	(29)
Pension and other postretirement benefits - noncurrent	(926)	(987)
Accumulated other comprehensive (gain) loss	$ (41)	$ 33	$ (29)

Retirement Plans (Net Periodic

Retirement Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Special termination benefits		$ 5	$ 26
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 90	97	88
Interest cost on projected benefit obligation	125	127	122
Expected return on plan assets	(192)	(186)	(168)
Amortization of unrecognized loss	24	30	40
Net periodic benefit cost	47	68	82
Pension settlement costs	41	83
Special termination benefits		5	23
Total Disclosed Benefit Cost	88	156	105
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	21	21	19
Interest cost on projected benefit obligation	38	40	37
Amortization of prior service (credit) costs	(9)	(9)	(9)
Amortization of unrecognized loss	3		1
Net periodic benefit cost	53	52	48
Special termination benefits			3
Total Disclosed Benefit Cost	$ 53	$ 52	$ 51

Retirement Plans (Weighted Aver

Retirement Plans (Weighted Average Asset Allocations, By Asset Category) (Details)	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundreths)	100.00%	100.00%
Equity Securties [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundreths)	48.00%	50.00%
Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundreths)	40.00%	40.00%
Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocation (in hundreths)	12.00%	10.00%

Retirement Plans (Expected Bene

Retirement Plans (Expected Benefit Payments Over The Next Ten Years) (Details) - Pension Benefits [Member] $ in Millions	Dec. 31, 2018USD ($)
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,019	$ 256
2,020	252
2,021	251
2,022	246
2,023	244
2024 - 2028	1,165
Total	$ 2,414

Retirement Plans (Schedule Of A

Retirement Plans (Schedule Of Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 01, 2016	Dec. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at year end to value obligation (in hundredths)	4.30%	3.70%	4.10%	4.00%	4.50%
Discount rate - used at beginning of year to compute annual cost (in hundredths)	3.70%	4.10%	4.50%
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%	2.50%	2.50%
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)	4.40%	3.80%	4.30%
Discount rate - used at beginning of year to compute annual cost (in hundredths)	3.80%	4.30%	4.70%
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)	4.30%	3.70%	4.10%
Discount rate - used at beginning of year to compute annual cost (in hundredths)	3.70%	4.10%	4.50%

Retirement Plans (Schedule Of E

Retirement Plans (Schedule Of Expected Benefit Payments For OPEB) (Details) $ in Millions	Dec. 31, 2018USD ($)
OPEB, Gross Benefits [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,019	$ 39
2,020	45
2,021	50
2,022	54
2,023	57
2024 - 2028	320
Total	565
Medicare Part D Subsidy [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2024 - 2028	2
Total	2
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2,019	39
2,020	45
2,021	50
2,022	54
2,023	57
2024 - 2028	322
Total	$ 567

Retirement Plans (Net Periodi_2

Retirement Plans (Net Periodic Benefit Cost Not Yet Recognized) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan [Abstract]
Net actuarial loss	$ 754	$ 556
Total	754	556	$ 647
Postretirement Benefits Other Than Pensions (OPEB) [Member]
Defined Benefit Plan [Abstract]
Net actuarial loss	(28)	54
Prior service cost (credit)	(13)	(21)
Total	$ (41)	$ 33	$ (29)

Retirement Plans (Amounts Recog

Retirement Plans (Amounts Recognized As A Component Of AOCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
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	$ 556	$ 647
Net actuarial loss recognized during year	(24)	(30)
Prior service credit recognized during year
Net actuarial (gain) loss occurring during year	263	22
Settlement loss recognized	(41)	(83)
Net amount recognized in comprehensive (loss) for the year	198	(91)
Accumulated other comprehensive (gain) loss at end of year	754	556
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	33	(29)
Net actuarial loss recognized during year	(3)
Prior service credit recognized during year	9	9
Net actuarial (gain) loss occurring during year	(80)	53
Settlement loss recognized
Net amount recognized in comprehensive (loss) for the year	(74)	62
Accumulated other comprehensive (gain) loss at end of year	$ (41)	$ 33

Fair Value Of Financial Instr_3

Fair Value Of Financial Instruments (Narrative) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Fair Value Of Financial Instruments [Abstract]
Reclassifications of investments between Level 1, 2, or 3	$ 0	$ 0

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, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	$ 1,344	$ 1,477
Common/Collective Trusts measured at net asset value	1,031	1,215
Interest and Dividend Receivable	6	6
Due from Broker for Securities Sold	20	40
Receivable Associated with Insurance Contract	7	7
Due to Broker for Securities Purchased	(60)	(71)
Total Plan Assets, at Fair Value	2,348	2,674
Cash and Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	36	37
U.S. Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	46	30
Corporate and Other Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	425	448
Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	420	523
Interest in Registered Investment Companies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	262	324
Interest in Limited Partnerships and Limited Liability Corporations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	155	115
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	718	884
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	36	37
Fair Value, Inputs, Level 1 [Member] | Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	420	523
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]
Investments at fair value	262	324
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	471	478
Fair Value, Inputs, Level 2 [Member] | U.S. Government Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	46	30
Fair Value, Inputs, Level 2 [Member] | Corporate and Other Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	425	448
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	155	115
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]
Investments at fair value	155	115
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]
Investments at fair value	$ 131	$ 167

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, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance, beginning of year	$ 115	$ 118
Realized gains	11	12
Unrealized gains (losses)	3	(2)
Purchases	37
Sales and distributions	(11)	(13)
Balance, end of year	$ 155	$ 115

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] - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 155,000,000	$ 115,000,000	$ 118,000,000
MS IFHF SVP LP Cayman [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1,000,000
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	$ 5,000,000
Liquidation Period (in years)	3 years
E. Casino Road, LLC (member)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 16,000,000
E. Casino Road, LLC (member) | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	7
Comm Drive, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 9,000,000
Comm Drive, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	7.75
CTE Drive, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 11,000,000
CTE Drive, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	9.50
Oakbrook Parkway LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 26,000,000
Oakbrook Parkway LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	7.75
West Jefferson, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 27,000,000
West Jefferson, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	8.75
MacCorkle Ave SE, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 14,000,000
MacCorkle Ave SE, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	8.50
S. Pike Road West, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1,000,000
S. Pike Road West, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	8.50
N. US 131, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1,000,000
N. US 131, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	9.50
E. Stockton Blvd, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 6,000,000
E. Stockton Blvd, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	7.25
E. Lime Street, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 8,000,000
E. Lime Street, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	9
N. Morgan Street, LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 30,000,000
N. Morgan Street, LLC [Member] | Measurement Input, Cap Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Leased properties, input	8.50

Fair Value Of Financial Instr_7

Fair Value Of Financial Instruments (Fair Value Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Carrying Amount [Member]
Long-term debt [Abstract]
Long-term debt	$ 16,358	$ 16,970
Fair Value [Member]
Long-term debt [Abstract]
Long-term debt	$ 11,942	$ 13,994

Commitments And Contingencies_2

Commitments And Contingencies (Narrative) (Details) $ in Millions	1 Months Ended		12 Months Ended
	Sep. 30, 2018propertycountyitem	Aug. 31, 2018USD ($)	Dec. 31, 2018USD ($)stateproperty	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Regulatory Commitments [Abstract]
Number of states of operation | state			29
Number of auctions | item	2
Operating Leases [Abstract]
Term Of Lease Arrangements Lower Range			1 year
Term Of Lease Arrangements Upper Range			99 years
Rental expense			$ 102	$ 106	$ 137
FCC Inquiry [Member]
Regulatory Commitments [Abstract]
Award in funding		$ 200
CAF Phase II [Member]
Regulatory Commitments [Abstract]
Annual support offered by the Federal Communications Commission			$ 332
Number of households to be serviced under regulatory funded programs | property			774,000
Auction 101 [Member]
Regulatory Commitments [Abstract]
Number of licenses | item	2
Number of counties | county	1,536
Auction 102 [Member]
Regulatory Commitments [Abstract]
Number of licenses | item	7
Number of economic areas | property	416
CTF Acquisition [Member] | CAF Phase II [Member]
Regulatory Commitments [Abstract]
Annual support offered by the Federal Communications Commission			$ 49

Commitments and Contingencies_3

Commitments and Contingencies (Future Minimum Rental Commitments For All Long-Term Noncancelable Operating Leases) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments And Contingencies [Abstract]
2,019	$ 73
2,020	18
2,021	14
2,022	13
2,023	11
Thereafter	89
Total minimum lease payments	$ 218

Commitments and Contingencies_4

Commitments and Contingencies (Future Payments For Obligations Under Noncancelable Long Distance Contracts And Service Agreements) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments And Contingencies [Abstract]
2,019	$ 44
2,020	35
2,021	26
2,022	2
2,023	2
Thereafter	7
Total	$ 116

Commitments and Contingencies_5

Commitments and Contingencies (Outstanding Performance Letters Of Credit) (Details) - Letter of Credit [Member] $ in Millions	Dec. 31, 2018USD ($)
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	$ 145
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	43
Zurich [Member]
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	52
All Other [Member]
Line of Credit Facility [Line Items]
Line of credit, amount outstanding	$ 1