Description of Business and Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation — The Condensed Consolidated Financial Statements of the Company have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) and, in the opinion of management, include all adjustments necessary for a fair presentation of the results of operations, other comprehensive income, financial position, and cash flows for each period presented. The adjustments referred to above are of a normal and recurring nature. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) have been condensed or omitted pursuant to SEC rules and regulations for interim reporting. The Condensed Consolidated Balance Sheet as of December 31, 2014 was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. These Condensed Consolidated Financial Statements should be read in conjunction with the Company’s 2014 Annual Report on Form 10-K. Operating results for the three months ended March 31, 2015 are not necessarily indicative of the results expected for the full year or any other interim period. The closing of our wireless operations represents a strategic shift in our business. Therefore, certain wireless assets, liabilities and results of operations will be reported as discontinued operations in our financial statements. Accordingly, the Company has recast its prior period results to be comparable with the current discontinued operations presentation with the exception of the Condensed Consolidated Statements of Cash Flows. See Note 2 for all required disclosures.
Use of Estimates	Use of Estimates — Preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported. Actual results could differ from those estimates. In the normal course of business, the Company is subject to various regulatory and tax proceedings, lawsuits, claims, and other matters. The Company believes adequate provision has been made for all such asserted and unasserted claims in accordance with U.S. GAAP. Such matters are subject to many uncertainties and outcomes that are not predictable with assurance.
Investment in CyrusOne	Equity Method Investments — Effective January 24, 2013, the completion date of CyrusOne's IPO, our ownership in CyrusOne is accounted for as an equity method investment. From that date, we recognize our proportionate share of CyrusOne's net income or loss as non-operating income or expense in our Condensed Consolidated Statement of Operations. For the quarter ended March 31, 2015 and 2014, the Company received cash dividends from CyrusOne totaling $6.0 million and $7.1 million, respectively. Dividends from CyrusOne are recognized as a reduction of our investment. During the second quarter of 2014, we invested a total of $5.5 million in other entities, which are accounted for as equity method investments, and the carrying value has been recorded in "Other noncurrent assets" in the Condensed Consolidated Balance Sheets. The Company's proportionate share of their respective net income is recorded in "Other expense, net" in the Condensed Consolidated Statement of Operations.
Income Taxes	Income Taxes — The Company’s income tax provision for interim periods is determined through the use of an estimated annual effective tax rate applied to year-to-date ordinary income, as well as the tax effects associated with discrete items. The Company expects its effective rate to exceed statutory rates primarily due to non-deductible expenses, including interest on securities originally issued to acquire its broadband business or securities subsequently issued to refinance those securities.
Recently Issued Accounting Standards	Recently Issued Accounting Standards — On January 9, 2015, the FASB issued Accounting Standard Update ("ASU") 2015-01, Income Statement-Extraordinary and Unusual Items. The updated standard will no longer allow for transactions that are unusual in nature and occur infrequently to be presented net-of-tax after income from continuing operations as an extraordinary item in the statements of operations. Under the new guidance, these transactions will be separately presented within income from continuing operations similar to current guidance for transactions that are unusual in nature or occur infrequently. The standard will be effective for us on January 1, 2016. The adoption of this pronouncement is not expected to have a material impact on our financial statements as there are no transactions presented as an extraordinary item. In April 2015, the FASB issued ASU 2015-03, Interest - Imputation of Interest, which changes the presentation of debt issuance costs in the financial statements. The amendments in this update require companies to present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset and to record amortization of the costs as interest expense. The standard will be effective on January 1, 2016 and will be applied retrospectively for prior periods. The Company estimates approximately $10 million of debt issuance costs will be reclassified from "Other non-current assets" to "Long term debt, less current portion" on the Condensed Consolidated Balance Sheets on the date of adoption. The adoption is not expected to impact the Statement of Operations. In April 2015, the FASB issued ASU 2015-05, Intangibles-Goodwill and Other-Internal-Use Software, which amends ASC 350-40 to provide customers with guidance on determining whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software. The standard will be effective on January 1, 2016 and can be adopted retrospectively or prospectively to arrangements entered into, or materially modified, after the effective date. The Company is currently in the process of evaluating the impact of adoption of this ASU on the Company’s consolidated financial statements. In April 2014, the FASB issued ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update increased the threshold for a disposal to qualify as a discontinued operation and require new disclosures of both discontinued operations and certain other disposals that do not meet the definition of a discontinued operation. The standard was effective for us on January 1, 2015 and the amended guidance has been applied to the discontinuation of our wireless operations. For a full discussion of discontinued operations and required disclosures reference Note 2. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This standard also includes expanded disclosure requirements that result in an entity providing users of financial statements with comprehensive information about the nature, amount, timing, and uncertainty of revenue and cash flows arising from the entity’s contracts with customers. This standard will be effective for us in the first quarter of the fiscal year ending December 31, 2017. The Company is currently in the process of evaluating the impact of adoption of this ASU on the Company’s consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern. The amendments provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. The standard will be effective for us on January 1, 2016. The adoption of this pronouncement is not expected to have a material impact on our financial statements
Earnings Per Share	Basic earnings per common share (“EPS”) is based upon the weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that would occur upon issuance of common shares for awards under stock-based compensation plans, exercise of warrants or conversion of preferred stock, but only to the extent that they are considered dilutive.
Fair Value Measurement	The fair value of our investment in CyrusOne was based on the closing market price of CyrusOne's common stock on March 31, 2015 and December 31, 2014. This fair value measurement is considered Level 1 of the fair value hierarchy. The fair value of our long-term debt was based on closing or estimated market prices of the Company’s debt at March 31, 2015 and December 31, 2014, which is considered Level 2 of the fair value hierarchy.

Disclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.

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Disclosure of accounting policy for the equity method of accounting for investments in common stock or other interests including unconsolidated subsidiaries, corporate joint ventures, noncontrolling interests in real estate ventures, limited partnerships, and limited liability companies. The accounting policy may include information such as: (1) initially recording an investment in the stock of an investee at cost; (2) adjusting the carrying amount of the investment to recognize the investor's share of the earnings or losses of the investee after the date of acquisition; and (3) adjustments to reflect the investor's share of changes in the investee's capital (dividends). This disclosure may also include a detailed description of the policy for determining the amount of equity method losses recognized after an investment has been reduced to zero as a result of previous losses, reasons for not using the equity method when the investor company owns 20 percent or more of the voting stock of the investee's company (including identification of the significant investee), reasons for using the equity method when the ownership percentage is less than 20 percent, and discussion of recognition of equity method losses when an investor's total investment in an investee includes, in addition to an investment in common stock, other investments such as preferred stock and loans to the investee. An entity also may describe how such investments are assessed for impairment.

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Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

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