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Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Property, Plant and Equipment [Abstract] Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Statement, Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Shares of Common Stock (no par value) Common Stock [Member] Additional Paid in Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (in shares) Common Stock, Shares, Outstanding Beginning balance Stockholders' Equity Attributable to Parent Change in Accounting Principle - Adoption of ASU 2014-09 Cumulative Effect of New Accounting Principle in Period of Adoption Net income Net Income (Loss) Attributable to Parent Other comprehensive gain (loss), net of tax Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Stock based compensation (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Stock based compensation Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Stock options exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Common stock issued Stock Issued During Period, Value, New Issues Shares retired for settlement of employee taxes upon issuance of vested equity awards (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Shares retired for settlement of employee taxes upon issuance of vested equity awards Adjustments Related to Tax Withholding for Share-based Compensation Common stock issued to acquire non-controlling interests of nTelos (in shares) Business Acquisition Noncontrolling Interest Issued Or Issuable Shares Assigned Number of shares (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity attributable to noncontrolling interests. Ending balance (in shares) Ending balance Leases [Abstract] Schedule of New Accounting Pronouncements and Changes in Accounting Principles Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Lease Income and Costs and Lease Terms and Discount Rates Lease, Cost [Table Text Block] Expected Maturity of Lease Liabilities, Operating Lessee, Operating Lease, Liability, Maturity [Table Text Block] Expected Maturity of Lease Liabilities, Financing Finance Lease, Liability, Maturity [Table Text Block] Minimum Rental Receipts Under Lease Agreement, Lessor, Operating Leases Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block] Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Investments [Abstract] Investments Fair Value Disclosures [Text Block] Other Liabilities Disclosure [Abstract] Other Assets and Accrued Liabilities Other Liabilities Disclosure [Text Block] Debt Disclosure [Abstract] Leverage ratio, actual Leverage Ratio, Actual Represents actual leverage ratio. Covenant requirement, total leverage ratio Ratio of Indebtedness to EBITDA Ratio of indebtedness to earnings before interest, taxes, depreciation and amortization. Debt service coverage ratio, actual Debt Service Coverage Ratio, Actual Represents actual debt service coverage ratio. Minimum debt service coverage ratio Minimum Debt Service Coverage Ratio Ratio of EBITDA divided by sum of all scheduled principal payments on Term Loans and regularly scheduled principal payments on other indebtedness plus cash interest. Covenant, liquidity balance, actual Debt Instrument, Covenant, Liquidity Balance, Actual Debt Instrument, Covenant, Liquidity Balance, Actual Debt instrument covenants minimum liquidity amount Debt Instrument Covenants Minimum Liquidity Amount Represents the minimum liquidity balance, defined as availability under the revolver facility plus unrestricted cash and cash equivalents on deposit in a deposit account for which a control agreement has been delivered to the administrative agent. Schedule of other investments which do not have readily determinable fair values Schedule Of Other Investments Which Do Not Have Readily Determinable Fair Values [Table Text Block] Tabular disclosure of other investments which do not have readily determinable fair values. Schedule of long term debt Schedule of Long-term Debt Instruments [Table Text Block] Financial covenants in credit agreements Financial Covenants In Credit Agreements [Table Text Block] Tabular disclosure of financial covenants in credit agreements. Revenue from Contract with Customer [Abstract] Remaining performance obligations Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Remaining performance obligations, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Derivative Instruments and Hedging Activities Disclosure [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Gains (Losses) on Cash Flow Hedges Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Attributable to Parent [Abstract] AOCI Attributable to Parent [Abstract] Accumulated Gains (Losses) on Cash Flow Hedges AOCI Attributable to Parent, Before Tax [Roll Forward] AOCI Attributable to Parent, Before Tax [Roll Forward] Balance as of December 31, 2018 AOCI before Tax, Attributable to Parent Net change in unrealized gain (loss) Other Comprehensive Income (Loss), before Reclassifications, before Tax Amounts reclassified from accumulated other comprehensive income to interest expense Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Net current period accumulated other comprehensive income (loss) Other Comprehensive Income (Loss), before Tax Balance as of September 30, 2019 Income Tax (Expense) Benefit AOCI Attributable to Parent, Tax [Roll Forward] AOCI Attributable to Parent, Tax [Roll Forward] Balance as of December 31, 2018 AOCI Tax, Attributable to Parent Net change in unrealized gain (loss) Other Comprehensive Income (Loss) before Reclassifications, Tax Amounts reclassified from accumulated other comprehensive income to interest expense Reclassification from AOCI, Current Period, Tax Net current period accumulated other comprehensive income (loss) Other Comprehensive Income (Loss), Tax Balance as of September 30, 2019 Accumulated Other Comprehensive Income (Loss), net of taxes AOCI Attributable to Parent, Net of Tax [Roll Forward] Balance as of December 31, 2018 Accumulated Other Comprehensive Income (Loss), Net of Tax Net change in unrealized gain (loss) Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive income to interest expense Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Net current period accumulated other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Balance as of September 30, 2019 Prepaid rent Prepaid Rent Prepaid maintenance expenses Prepaid Maintenance Expense, Current Prepaid Maintenance Expense, Current Interest rate swaps Derivative Asset, Current Wireless contract asset Wireless Contract Asset, Current Wireless Contract Asset, Current Contract acquisition and fulfillment costs Capitalized Contract Cost, Net, Current Other Other Assets, Current Prepaid expenses and other Prepaid Expense and Other Assets, Current New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Cable Cable [Member] The Cable segment provides video, internet and voice services in Virginia, West Virginia and Maryland. It includes the operations acquired from Jet Broadband, LLC, since July 30, 2010, and the operations acquired from Sudden link since November 30, 2010. Wireline Wireline [Member] The Wireline segment provides regulated and unregulated voice services, dial-up and DSL internet access, and long distance access services throughout Shenandoah County and portions of northwestern Augusta County, Virginia, and leases fiber optic facilities throughout the northern Shenandoah Valley of Virginia, northern Virginia and adjacent areas along the Interstate 81 corridor, including portions of West Virginia and Maryland. New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Management fee, percentage Management Fee, Percent Fee Postpaid wireless service fee as a deduction from gross revenues. Service fee retained by Sprint Net Service Fee, Percent Fee Post paid service fee percentage retained by Sprint. Management fee on prepaid wireless revenues and costs Management Fee Retained, Percent Fee Prepaid wireless service fee percentage retained by Sprint. Revenue Monthly Revenue From Contract With Customer Monthly Revenue From Contract With Customer Reimbursement payment, cost of equipment and commissions, benefit period for recognition Reimbursement Payment, Cost Of Equipment And Commissions, Benefit Period For Recognition Reimbursement Payment, Cost Of Equipment And Commissions, Benefit Period For Recognition Installation revenue, recognition period Revenue Recognition, Period Revenue Recognition, Period Commissions and other costs, recognition period (in months) Revenue, Commissions and Other Costs, Recognition Period Revenue, Commissions and Other Costs, Recognition Period Capitalized contract costs, average customer life (in months) Capitalized Contract Cost, Amortization Period Income Statement [Abstract] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Service revenue and other Service Revenue and Other [Member] Service Revenue and Other [Member] Equipment revenue Equipment Revenue [Member] Equipment Revenue [Member] Cost of services Service [Member] Cost of goods sold Product [Member] Statement [Line Items] Operating revenue: Revenues [Abstract] Operating revenues Revenue from Contract with Customer, Excluding Assessed Tax Operating expenses: Operating Expenses [Abstract] Cost of services Cost of Goods and Services Sold Selling, general and administrative Selling, General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Total operating expenses Operating Expenses Operating income Operating Income (Loss) Other income (expense): Other Income and Expenses [Abstract] Interest expense Interest Expense Other Other Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net income Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized gain (loss) on interest rate hedge, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Unrealized gain (loss) on interest rate hedge, net of tax Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Net income per share, basic and diluted: Earnings Per Share, Basic and Diluted [Abstract] Basic net income per share (in dollars per share) Earnings Per Share, Basic Diluted net income per share (in dollars per share) Earnings Per Share, Diluted Weighted average shares outstanding, basic (in shares) Weighted Average Number of Shares Outstanding, Basic Weighted average shares outstanding, diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Megahertz spectrum used Megahertz spectrum range used Radio frequencies used by the company. Initial term of contract Term of Contract Initial term of the contract. Number of contract renewals Number of Contract Renewals The number of times that a contract can be extended beyond its initial term. Length of renewals Length of Renewals Length of renewals after the initial term of a contract. Right or obligation to sell business, percentage of EBV Right or obligation to sell business The percentage of the Entire Business value the company has a right or obligation to sell business upon non-renewal, under the agreement. Operating Leases Operating Lease Liabilities, Payments Due [Abstract] 2019 Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five 2024 and thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total lease payments Lessee, Operating Lease, Liability, Payments, Due Less: Interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of lease liabilities Operating Lease, Liability Finance Leases Finance Lease Liabilities, Payments, Due [Abstract] 2019 Finance Lease, Liability, Payments, Remainder of Fiscal Year 2020 Finance Lease, Liability, Payments, Due Year Two 2021 Finance Lease, Liability, Payments, Due Year Three 2022 Finance Lease, Liability, Payments, Due Year Four 2023 Finance Lease, Liability, Payments, Due Year Five 2024 and thereafter Finance Lease, Liability, Payments, Due after Year Five Total lease payments Finance Lease, Liability, Payments, Due Less: Interest Finance Lease, Liability, Undiscounted Excess Amount Present value of lease liabilities Finance Lease, Liability Total Lease Liabilities, Payments, Due [Abstract] Lease Liabilities, Payments, Due [Abstract] 2019 Lessee, Lease Liability, Payments, Remainder of Fiscal Year Lessee, Lease Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Lease Liability, Payments, Due Year Two Lessee, Lease Liability, Payments, Due Year Two 2021 Lessee, Lease Liability, Payments, Due Year Three Lessee, Lease Liability, Payments, Due Year Three 2022 Lessee, Lease Liability, Payments, Due Year Four Lessee, Lease Liability, Payments, Due Year Four 2023 Lessee, Lease Liability, Payments, Due Year Five Lessee, Lease Liability, Payments, Due Year Five 2024 and thereafter Lessee, Lease Liability, Payments, Due After Year Five Lessee, Lease Liability, Payments, Due After Year Five Total lease payments Lessee, Lease Liability, Payments, Due Lessee, Lease Liability, Payments, Due Less: Interest Lessee, Lease Liability, Undiscounted Excess Amount Lessee, Lease Liability, Undiscounted Excess Amount Total lease liabilities Lease, Liability Lease, Liability Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Buildings and structures Building and Building Improvements [Member] Cable and fiber Other Machinery and Equipment [Member] Equipment and software Equipment and Software [Member] Purchased software applications and internally developed software for sale, licensing or long-term internal use and related equipment. Plant in service Other Plant in Service [Member] Plant under construction Asset under Construction [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Useful life (in years) Property, Plant and Equipment, Useful Life Property, plant and equipment [Abstract] Property, Plant and Equipment, Net, by Type [Abstract] Total property, plant and equipment Property, Plant and Equipment, Gross Less accumulated amortization and depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant and equipment, net Property, Plant and Equipment, Net Depreciation expense Accumulated Depreciation, Depletion and Amortization, Property, Plant and Equipment, Period Increase (Decrease) Statement of Cash Flows [Abstract] Cash Flows From Operating Activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation Depreciation Amortization Amortization Reflected as Operating Expense The aggregate amount of recurring noncash operating expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives. Accretion of asset retirement obligations Asset Retirement Obligation, Accretion Expense Bad debt expense Provision for Doubtful Accounts Stock based compensation expense, net of amount capitalized Share-based Compensation Deferred income taxes Deferred Income Taxes and Tax Credits Net gain from patronage and investments Income (Loss) from Equity Method Investments Amortization of long-term debt issuance costs Amortization of Debt Issuance Costs Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Inventory, net Increase (Decrease) in Inventories Current income taxes Current Income Tax Expense (Benefit) Waived management fee Management Fee, Amount Waived Management Fee, Amount Waived Other assets Increase (Decrease) in Other Noncurrent Assets Operating lease right-of-use assets Increase (Decrease) In Operating Lease, Right-Of Use Asset Increase (Decrease) In Operating Lease, Right-Of Use Asset Lease liabilities Increase (Decrease) In Lease Liability Increase (Decrease) In Lease Liability Accounts payable Increase (Decrease) in Accounts Payable Deferred lease Increase (Decrease) in Deferred Liabilities Other deferrals and accruals Increase (Decrease) in Other Accrued Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Cash disbursed for acquisitions Payments to Acquire Businesses, Gross Cash disbursed for FCC spectrum licenses Payments to Acquire Intangible Assets Proceeds from sale of assets and other Proceeds from Sale of Machinery and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Principal payments on long-term debt Repayments of Long-term Debt Proceeds from revolving credit facility borrowings Proceeds from Long-term Lines of Credit Principal payments on revolving credit facility Repayments of Long-term Lines of Credit Proceeds from exercises of stock options Proceeds from Stock Options Exercised Taxes paid for equity award issuances Payments Related to Tax Withholding for Share-based Compensation Other Proceeds from (Payments for) Other Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents, beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents, end of period Subsequent Event [Table] Subsequent Event [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Stock Repurchase Program Stock Repurchase Program [Member] Stock Repurchase Program [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Common stock dividend approved (in usd per share) Common Stock, Dividends, Per Share, Declared Amount of common stock repurchased Stock Repurchase Program, Authorized Amount Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swap Interest Rate Swap [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Derivatives designated as hedging instruments Designated as Hedging Instrument [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Prepaid expenses and other Prepaid Expenses and Other Current Assets [Member] Deferred charges and other assets, net Deferred Charges and Other Assets, Net [Member] Line item in the statement of financial position in which the fair value amounts of the derivative instruments are included. Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract] Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract] Derivative assets Derivative Asset Total derivatives designated as hedging instruments Derivative Assets (Liabilities), at Fair Value, Net Contract Asset Balances and Activity Contract with Customer, Asset and Liability [Table Text Block] Revenue, Remaining Performance Obligation Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Amortized and Capitalized Contract Costs Capitalized Contract Cost [Table Text Block] Leases Lessor, Operating Leases [Text Block] Leases Lessee, Operating Leases [Text Block] Leases Lessor, Sales-type Leases [Text Block] Leases Lessee, Finance Leases [Text Block] Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Non-current portion of deferred revenues Contract with Customer, Liability, Noncurrent FCC spectrum licenses FCC Spectrum Licenses Leases, Non-current FCC Spectrum Licenses Leases, Non-current Noncurrent portion of financing leases Finance Lease, Liability, Noncurrent Other Other Accrued Liabilities, Noncurrent Other liabilities Other Liabilities, Noncurrent Adoption of New Accounting Principles Policy New Accounting Pronouncements, Policy [Policy Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Service revenue Services Revenue [Member] Services Revenue [Member] Equipment revenue Tower revenue Tower Revenue [Member] Tower Revenue [Member] Other revenue Other Revenue [Member] Other Revenue [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Intersegment Eliminations Intersegment Eliminations [Member] Operating Segments Operating Segments [Member] Wireless Wireless [Member] The Wireless segment provides digital wireless service to a portion of a four-state area covering the region from Harrisburg, York and Altoona, Pennsylvania, to Harrisonburg, Virginia, as a Sprint PCS Affiliate of Sprint Nextel. This segment also owns cell site towers built on leased land, and leases space on these towers to both affiliates and non-affiliated service providers. Other Other Segments [Member] Eliminations Eliminations [Member] Eliminations [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract] External revenue External revenues [Abstract] Depreciation and amortization Revenue from Contracts with Customers Revenue from Contract with Customer [Text Block] Investment [Table] Investment [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Domestic equity funds Domestic equity funds [Member] Equity securities issued by domestic or foreign corporate business, banks and other entities with a promise of repayment. International equity funds Foreign Corporate Equity Securities [Member] Foreign Corporate Equity Securities [Member] Investment Type [Axis] Investment Type [Axis] Investment [Domain] Investments [Domain] CoBank CoBank [Member] Equity securities investments. Other Other Equity Investments [Member] Equity securities investments. Investment [Line Items] Investment [Line Items] Total investments carried at fair value Equity Securities, FV-NI Total investments carried at cost Equity Securities, FV-NI, Cost Total equity method investments Equity Method Investment, Aggregate Cost Total investments Other Long-term Investments Customer Concentration Collaborative Arrangement Disclosure [Text Block] Derivative [Table] Derivative [Table] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedge Cash Flow Hedging [Member] Derivative [Line Items] Derivative [Line Items] Notional amount of cash flow hedges Derivative Asset, Notional Amount Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Business Combinations [Abstract] Acquisition Business Combination Disclosure [Text Block] Commitments under leases under ASU 840, 2019 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year Commitments under leases under ASU 840, 2020 Operating Leases, Future Minimum Payments, Due in Two Years Commitments under leases under ASU 840, 2021 Operating Leases, Future Minimum Payments, Due in Three Years Commitments under leases under ASU 840, 2022 Operating Leases, Future Minimum Payments, Due in Four Years Commitments under leases under ASU 840, 2023 Operating Leases, Future Minimum Payments, Due in Five Years Commitments under leases under ASU 840, thereafter Operating Leases, Future Minimum Payments, Due Thereafter Selected Financial Data for Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Effect of the Adoption of ASC Topic 842 (Leases) Accounting Standards Update 2016-02 [Member] Assets Assets [Abstract] Prepaid expenses and other Property, plant and equipment, net Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Liabilities Liabilities [Abstract] Current operating lease liabilities Operating Lease, Liability, Current Accrued liabilities and other Accrued Liabilities, Current Deferred Lease Deferred Rent Credit Noncurrent operating lease liabilities Operating Lease, Liability, Noncurrent Other liabilities Lease income from operating leases - fixed Sublease Income Operating lease expense Operating Lease, Cost Amortization of lease assets Finance Lease, Right-of-Use Asset, Amortization Interest on finance lease liabilities Finance Lease, Interest Expense Subtotal finance lease cost Finance Lease, Cost Finance Lease, Cost Total lease expense Lease, Cost Sales and property taxes payable Sales And Property Taxes Payable, Current Sales And Property Taxes Payable, Current Asset retirement obligations Asset Retirement Obligation, Current Accrued programming costs Accrued Programming Costs, Current Accrued Programming Costs, Current Financing leases Finance Lease, Liability, Current FCC spectrum licenses FCC Spectrum Licenses Leases, Current FCC Spectrum Licenses Leases, Current Other current liabilities Other Accrued Liabilities, Current Accrued liabilities and other 2019 Lessor, Operating Lease, Payments to be Received, Remainder of Fiscal Year 2020 Lessor, Operating Lease, Payments to be Received, Two Years 2021 Lessor, Operating Lease, Payments to be Received, Three Years 2022 Lessor, Operating Lease, Payments to be Received, Four Years 2023 Lessor, Operating Lease, Payments to be Received, Five Years 2024 and thereafter Lessor, Operating Lease, Payments to be Received, Thereafter Total lease income Lessor, Operating Lease, Payments to be Received Schedule of Goodwill [Table] Schedule of Goodwill [Table] Wireless Goodwill [Line Items] Goodwill [Line Items] Goodwill Goodwill Capitalized Contract Cost [Roll Forward] Capitalized Contract Cost [Roll Forward] Capitalized Contract Cost [Roll Forward] Beginning Balance Capitalized Contract Cost, Net Contract payments Capitalized Contract Cost, Payments Capitalized Contract Cost, Payments Contract amortization Capitalized Contract Cost, Amortization Ending Balance Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Cable franchise rights Franchise Rights [Member] FCC spectrum licenses FCC Spectrum Licenses [Member] FCC Spectrum Licenses [Member] Railroad crossing rights Railroad Crossing Rights [Member] Railroad Crossing Rights [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Sprint affiliate contract expansion - Wireless Affiliate Contract Expansion - Wireless [Member] Affiliate Contract Expansion - Wireless [Member] FCC spectrum licenses FCC Spectrum License Leases [Member] FCC Spectrum License Leases [Member] Favorable leases - Wireless Favorable Leases Wireless [Member] Refers to favorable leases wireless. Acquired subscribers - Cable Acquired Subscribers Cable [Member] Refers to acquired subscribers cable. Other intangibles Other Intangible Assets [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Total non-amortizing intangibles Indefinite-lived Intangible Assets (Excluding Goodwill) Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization and Other Finite-Lived Intangible Assets, Accumulated Amortization Net Finite-Lived Intangible Assets, Net Total intangible assets, gross Intangible Assets, Gross (Excluding Goodwill) Total intangible assets, net Waived management fees under affiliate agreement Waived Management Fees Under Affiliate Agreement Waived Management Fees Under Affiliate Agreement Waived management fees under affiliate agreement, expected to be collected Waived Management Fees Under Affiliate Agreement, Amount Expected To Collect Waived Management Fees Under Affiliate Agreement, Amount Expected To Collect Waived management fees under affiliate agreement amount expected to collect monthly Waived Management Fees Under Affiliate Agreement Amount Expected To Collect Monthly Waived Management Fees Under Affiliate Agreement Amount Expected To Collect Monthly Indefinite-lived intangible assets acquired Indefinite-lived Intangible Assets Acquired Finite-lived intangible assets acquired Finite-lived Intangible Assets Acquired Remaining lease term (in years) Asset Acquisition, Remaining Lease Term Asset Acquisition, Remaining Lease Term Derivatives and Hedging Derivative Instruments and Hedging Activities Disclosure [Text Block] Awards excluded from the computation of diluted net income per share because their inclusion would have been anti-dilutive (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Term loan A-1 Term loan A-1 [Member] Loan from a bank/financial institution for a specific amount that has a specified repayment schedule and a fixed/floating interest rate. Term loan A-2 Term loan A-2 [Member] Loan from a bank/financial institution for a specific amount that has a specified repayment schedule and a fixed/floating interest rate. Debt Instrument [Line Items] Debt Instrument [Line Items] Long-term debt Long-term Debt Less: unamortized loan fees Unamortized Loan Fees, Net Represents the net unamortized loan fees. Total debt, net of unamortized loan fees Total debt, net of unamortized loan fees Amount after unamortized loan fees of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Current maturities of long-term debt, net of current unamortized loan fees Current maturities, net of unamortized loan fees Amount, after unamortized loan fees classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Long-term debt, less current maturities, net of unamortized loan fees Long-term debt, net of unamortized loan fees Amount after unamortized loan fees of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Subscriber Relationships Customer Relationships [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Big Sandy Acquisition Big Sandy Acquisition [Member] Big Sandy Acquisition [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Cash purchase price Business Combination, Consideration Transferred Property, plant and equipment acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Subscriber relationships acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Goodwill acquired Estimated useful life, acquired property, plant and equipment Estimated useful life, acquired intangible asset Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Long-Term Debt Debt Disclosure [Text Block] Statement of Financial Position [Abstract] Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Inventory reserve Inventory Valuation Reserves Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Schedule of Derivative Financial Instrument as Well as its Classification on the Consolidated Balance Sheet Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Calculation of net income per share: Earnings Per Share, Basic [Abstract] Basic weighted average shares outstanding (in shares) Basic income per share (in dollars per share) Effect of stock options outstanding: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Effect from dilutive shares and options outstanding (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted weighted average shares (in shares) Diluted income per share (in dollars per share) Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) [Member] Total debt, net of unamortized loan fees Unamortized loan fees Effective rate Debt Instrument, Interest Rate, Effective Percentage Leverage ratio threshold Debt Instrument, Leverage Ratio Threshold Debt Instrument, Leverage Ratio Threshold Variable interest rate Debt Instrument, Basis Spread on Variable Rate Periodic payment of principal Debt Instrument, Periodic Payment, Principal Periodic payment principal, period two Debt Instrument, Periodic Payment Principal, Period Two Amount of the required periodic payments applied to principal period two. Periodic payment principal, period three Debt Instrument, Periodic Payment Principal, Period Three Debt Instrument, Periodic Payment Principal, Period Three Additional payment to required quarterly payments Debt Instrument, Additional Payment To Required Quarterly Payments Debt Instrument, Additional Payment To Required Quarterly Payments Cash paid for interest, net of amounts capitalized Interest Paid, Excluding Capitalized Interest, Operating Activities Effective tax rate Effective Income Tax Rate Reconciliation, Percent Cash income taxes paid Income Taxes Paid Cash income tax refunds Proceeds from Income Tax Refunds Changes in Carrying Amount of Goodwill Schedule of Goodwill [Table Text Block] Schedule of Intangible Assets Schedule of Intangible Assets and Goodwill [Table Text Block] Operating cash flows used by leases Operating Lease, Payments Leased assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Contract Asset Balance [Roll Forward] Contract Asset Balance [Roll Forward] Contract Asset Balance [Roll Forward] Beginning balance Contract with Customer, Asset, Net Contract payments Contract with Customer, Assets, Payments Contract with Customer, Assets, Payments Contract amortization Contract with Customer, Reduction in Revenue, Amortization Contract with Customer, Reduction in Revenue, Amortization Ending balance Interest rate swaps Wireless contract asset Wireless Contract Asset, Noncurrent Wireless Contract Asset, Noncurrent Contract acquisition and fulfillment costs Capitalized Contract Cost, Net, Noncurrent Other Other Assets, Noncurrent Deferred charges and other assets Deferred Costs, Noncurrent Schedule of Other Current Assets Schedule of Other Current Assets [Table Text Block] Schedule of Other Assets, Noncurrent Schedule of Other Assets, Noncurrent [Table Text Block] Summary of Accrued Liabilities and Other Other Current Liabilities [Table Text Block] Summary of Other Liabilities Other Noncurrent Liabilities [Table Text Block] Earnings Per Share (EPS) Earnings Per Share [Text Block] ASSETS Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable, net of allowance for doubtful accounts of $563 and $534, respectively Accounts Receivable, Net, Current Income taxes receivable Income Taxes Receivable, Current Inventory, net of allowances of $196 and $113, respectively Inventory, Net Total current assets Assets, Current Investments Long-term Investments Deferred charges and other assets Total assets Assets LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Current maturities of long-term debt, net of unamortized loan fees Long-term Debt, Current Maturities Accounts payable Accounts Payable, Current Advanced billings and customer deposits Contract with Customer, Liability, Current Accrued compensation Accrued Salaries, Current Total current liabilities Liabilities, Current Long-term debt, less current maturities, net of unamortized loan fees Long-term Debt, Excluding Current Maturities Other long-term liabilities: Other Liabilities, Noncurrent [Abstract] Deferred income taxes Deferred Income Tax Liabilities, Net Deferred lease Asset retirement obligations Asset Retirement Obligations, Noncurrent Retirement plan obligations Liability, Defined Benefit Plan, Noncurrent Total other long-term liabilities Liabilities, Other than Long-term Debt, Noncurrent Shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock, no par value, authorized 96,000; 49,857 and 49,630 issued and outstanding at September 30, 2019 and December 31, 2018, respectively Common Stock, Value, Issued Additional paid in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss), net of taxes Total shareholders’ equity Total liabilities and shareholders’ equity Liabilities and Equity Weighted-average remaining lease term (years) Weighted-Average Remaining Lease Term [Abstract] Weighted-Average Remaining Lease Term [Abstract] Operating leases Operating Lease, Weighted Average Remaining Lease Term Finance leases Finance Lease, Weighted Average Remaining Lease Term Weighted-average discount rate Weighted-Average Discount Rate [Abstract] Weighted-Average Discount Rate [Abstract] Operating leases Operating Lease, Weighted Average Discount Rate, Percent Finance leases Finance Lease, Weighted Average Discount Rate, Percent Segment Reporting Segment Reporting Disclosure [Text Block]