Description of Business and Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Policy [Policy Text Block]	Equity Method Investments - We completed the IPO of CyrusOne on January 24, 2013, and as of that date, we have significant influence over CyrusOne but do not control its operations. As a result, effective January 24, 2013, 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 consolidated statement of operations. For the period January 1, 2013 through January 23, 2013, we consolidated CyrusOne's operating results. For the three and nine months ended September 30, 2014, the Company received cash dividends from CyrusOne totaling $6.0 million and $22.4 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 two limited liability companies. These investments are accounted for under the equity method and the carrying value has been recorded within “Other noncurrent assets” in the condensed consolidated balance sheet as of September 30, 2014. During the third quarter we recognized our proportionate share of the investments’ net loss as non-operating expense in our consolidated statement of operations, which had a minimal impact on our consolidated statement of operations.
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, 2013 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 2013 Annual Report on Form 10-K. Operating results for the three and nine months ended September 30, 2014 are not necessarily indicative of the results expected for the full year or any other interim period.
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.
Property, Plant and Equipment	Property, Plant and Equipment — Property, plant and equipment is stated at original cost and presented net of accumulated depreciation and impairment losses. Depreciation expense is generally calculated using either the group depreciation method or the straight-line method. In the first quarter of 2013, and in connection with our review of the estimated remaining useful lives of property, plant and equipment, we shortened the estimated useful lives assigned to the wireless network software to three years. This change resulted from smartphone-driven technology upgrades, enhancements and projected retirements. For the three months ended March 31, 2013, the increase in depreciation expense associated with this change was $8.5 million and increased basic and diluted loss per share by approximately $0.03 per share. In conjunction with our long-lived asset impairment analysis conducted in the fourth quarter of 2013, we reassessed the useful lives of all our Wireless property, plant and equipment. The remaining useful life for all Wireless property, plant, and equipment assets was reduced to 30 months as of December 31, 2013. In the second quarter of 2014, following the agreement to sell our wireless spectrum licenses and certain other assets, we further reduced the remaining useful life of those assets not included in the sale to be fully depreciated as of March 31, 2015. As a result of these changes in estimate, depreciation expense increased by approximately $50 million for the nine months ended September 30, 2014 and reduced basic and diluted earnings per share by approximately $0.14 per share. In addition, adjusting the useful life of our Wireless property, plant and equipment also required that we reduce the amortization period of the deferred gain associated with the 2009 tower sale in a similar manner. Amortization of the deferred gain associated with the tower sale totaled $16.5 million and $1.7 million in the nine months ended September 30, 2014 and 2013, respectively. In conjunction with the close of the sale of our wireless spectrum licenses and certain other assets on September 30, 2014, an asset impairment charge of $7.5 million was recorded in the three months ended September 30, 2014 for the write-off of certain construction-in-progress projects that will no longer be completed due to the wind down of wireless 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 tax rate to exceed statutory rates primarily due to non-deductible expenses, including interest on securities originally issued to acquire its broadband business or securities that the Company subsequently issued to refinance those securities. The Company believes the full year 2014 effective tax rate will approximate the actual September 2014 year-to-date effective tax rate.
Recently Issued Accounting Standards	Recently Issued Accounting Standards — In July 2013, the FASB issued new guidance under Accounting Standards Update ("ASU") 2013-11 regarding the presentation of unrecognized tax benefits in financial statements. This new standard requires the netting in the balance sheet of unrecognized tax benefits against a deferred tax asset for a same-jurisdiction loss or other carryforward that would apply in settlement of the uncertain tax positions. To the extent a net operating loss ("NOL") or tax credit carryforward is not available under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position, the unrecognized tax benefit would be presented in the balance sheet as a liability. This standard went into effect for annual and interim periods beginning after December 15, 2013. We adopted this new guidance beginning with our interim financial statements for the three months ended March 31, 2014. The adoption of this standard did not have a material impact on our financial statements for the nine months ending September 30, 2014. 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 will be effective for us on January 1, 2015. The adoption of this pronouncement may affect our presentation and disclosure of any future dispositions. 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 or conversion of preferred stock, but only to the extent that they are considered dilutive.
Fair Value Measurements	The fair value of our investment in CyrusOne was based on the closing market price of CyrusOne's common stock on September 30, 2014 and December 31, 2013. This fair value measurement is considered Level 1 of the fair value hierarchy. The fair value of our long-term debt was based on the closing or estimated market prices of the Company’s debt at September 30, 2014 and December 31, 2013, 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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Disclosure of accounting policy for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, basis of assets, depreciation and depletion methods used, including composite deprecation, estimated useful lives, capitalization policy, accounting treatment for costs incurred for repairs and maintenance, capitalized interest and the method it is calculated, disposals and impairments.

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