Subsequent Events Subsequent Events	6 Months Ended
Jun. 30, 2017
Subsequent Event [Line Items]
Subsequent Events [Text Block]	Subsequent Events Proposed Lightower Acquisition On July 18, 2017, the Company announced that it has entered into a definitive agreement ("Merger Agreement") to acquire LTS Group Holdings LLC ("Lightower") from Berkshire Partners, Pamlico Capital and other investors for approximately $7.1 billion in cash (subject to certain limited adjustments) ("Proposed Lightower Acquisition"). Lightower owns or has rights to approximately 32,000 route miles of fiber located primarily in top metro markets in the Northeast, including Boston, New York and Philadelphia. The Company expects to finance the Proposed Lightower Acquisition, including related fees and expenses, utilizing proceeds from (1) the July 2017 Common Stock Offering (as defined below), (2) the Mandatory Convertible Preferred Stock Offering (as defined below), and (3) the August 2017 Senior Notes Offering (as defined below). The Company expects the Proposed Lightower Acquisition to close by the end of 2017. Completion of the Proposed Lightower Acquisition is subject to customary closing conditions and does not require the approval of the Company's stockholders. July 2017 Equity Financings On July 26, 2017, the Company completed an offering of 40.15 million shares of common stock, including certain additional shares sold pursuant to the underwriters' option, which generated net proceeds of approximately $3.8 billion ("July 2017 Common Stock Offering"). The Company intends to use the net proceeds of the July 2017 Common Stock Offering to partially fund the Proposed Lightower Acquisition and pay related fees and expenses. On July 26, 2017, the Company completed an offering of 1.65 million shares of the Company's 6.875% Mandatory Convertible Preferred Stock, Series A, par value $0.01 per share, at $1,000 per share ("Mandatory Convertible Preferred Stock"), including certain additional shares sold pursuant to the underwriters' option, which generated net proceeds of approximately $1.6 billion ("Mandatory Convertible Preferred Stock Offering"). The Company intends to use the net proceeds from the Mandatory Convertible Preferred Stock Offering to partially fund the Proposed Lightower Acquisition and pay related fees and expenses. The holders of the Mandatory Convertible Preferred Stock are entitled to receive cumulative dividends, when and if declared by the Company's board of directors, at the rate of 6.875% on the liquidation preference of $1,000 per share. The dividends may be paid in cash or, subject to certain limitations, in shares of the Company's common stock or any combination of cash and shares of common stock on February 1, May 1, August 1 and November 1 of each year, commencing on November 1, 2017 and to, and including, August 1, 2020. The terms of the Mandatory Convertible Preferred Stock provide that, unless accumulated dividends have been paid or set aside for payment on all outstanding shares of Mandatory Convertible Preferred Stock for all past dividend periods, no dividends may be declared or paid on common stock. Unless converted earlier, each outstanding share of the Mandatory Convertible Preferred Stock will automatically convert on August 1, 2020 into between 8.6806 and 10.4167 shares of the Company's common stock, depending on the applicable market value of the common stock and subject to certain anti-dilution adjustments. At any time prior to August 1, 2020, holders of the Mandatory Convertible Preferred Stock may elect to convert all or a portion of their shares into common stock at the minimum conversion rate of 8.6806, subject to certain anti-dilution adjustments. The July 2017 Common Stock Offering and Mandatory Convertible Preferred Stock Offering are collectively referred to herein as "July 2017 Equity Financings." August 2017 Senior Notes Offering On August 1, 2017, the Company issued $750 million aggregate principal amount of 3.200% senior unsecured notes due 2024 ("3.2% Senior Notes") and $1.0 billion aggregate principal amount of 3.650% senior unsecured notes due 2027 ("3.65% Senior Notes") (collectively, "August 2017 Senior Notes Offering"). The Company intends to use the net proceeds of the August 2017 Senior Notes Offering to partially fund the Proposed Lightower Acquisition and pay related fees and expenses. Common Stock Dividend On August 3, 2017, the Company's board of directors declared a quarterly common stock cash dividend of $0.95 per share. The common stock dividend will be paid on September 29, 2017 to common stockholders of record as of September 15, 2017.

Subsequent Events

Proposed Lightower Acquisition

On July 18, 2017, the Company announced that it has entered into a definitive agreement ("Merger Agreement") to acquire LTS Group Holdings LLC ("Lightower") from Berkshire Partners, Pamlico Capital and other investors for approximately $7.1 billion in cash (subject to certain limited adjustments) ("Proposed Lightower Acquisition"). Lightower owns or has rights to approximately 32,000 route miles of fiber located primarily in top metro markets in the Northeast, including Boston, New York and Philadelphia. The Company expects to finance the Proposed Lightower Acquisition, including related fees and expenses, utilizing proceeds from (1) the July 2017 Common Stock Offering (as defined below), (2) the Mandatory Convertible Preferred Stock Offering (as defined below), and (3) the August 2017 Senior Notes Offering (as defined below). The Company expects the Proposed Lightower Acquisition to close by the end of 2017. Completion of the Proposed Lightower Acquisition is subject to customary closing conditions and does not require the approval of the Company's stockholders.

July 2017 Equity Financings

On July 26, 2017, the Company completed an offering of 40.15 million shares of common stock, including certain additional shares sold pursuant to the underwriters' option, which generated net proceeds of approximately $3.8 billion ("July 2017 Common Stock Offering"). The Company intends to use the net proceeds of the July 2017 Common Stock Offering to partially fund the Proposed Lightower Acquisition and pay related fees and expenses.

On July 26, 2017, the Company completed an offering of 1.65 million shares of the Company's 6.875% Mandatory Convertible Preferred Stock, Series A, par value $0.01 per share, at $1,000 per share ("Mandatory Convertible Preferred Stock"), including certain additional shares sold pursuant to the underwriters' option, which generated net proceeds of approximately $1.6 billion ("Mandatory Convertible Preferred Stock Offering"). The Company intends to use the net proceeds from the Mandatory Convertible Preferred Stock Offering to partially fund the Proposed Lightower Acquisition and pay related fees and expenses.

The holders of the Mandatory Convertible Preferred Stock are entitled to receive cumulative dividends, when and if declared by the Company's board of directors, at the rate of 6.875% on the liquidation preference of $1,000 per share. The dividends may be paid in cash or, subject to certain limitations, in shares of the Company's common stock or any combination of cash and shares of common stock on February 1, May 1, August 1 and November 1 of each year, commencing on November 1, 2017 and to, and including, August 1, 2020. The terms of the Mandatory Convertible Preferred Stock provide that, unless accumulated dividends have been paid or set aside for payment on all outstanding shares of Mandatory Convertible Preferred Stock for all past dividend periods, no dividends may be declared or paid on common stock.

Unless converted earlier, each outstanding share of the Mandatory Convertible Preferred Stock will automatically convert on August 1, 2020 into between 8.6806 and 10.4167 shares of the Company's common stock, depending on the applicable market value of the common stock and subject to certain anti-dilution adjustments. At any time prior to August 1, 2020, holders of the Mandatory Convertible Preferred Stock may elect to convert all or a portion of their shares into common stock at the minimum conversion rate of 8.6806, subject to certain anti-dilution adjustments.

The July 2017 Common Stock Offering and Mandatory Convertible Preferred Stock Offering are collectively referred to herein as "July 2017 Equity Financings."

August 2017 Senior Notes Offering

On August 1, 2017, the Company issued $750 million aggregate principal amount of 3.200% senior unsecured notes due 2024 ("3.2% Senior Notes") and $1.0 billion aggregate principal amount of 3.650% senior unsecured notes due 2027 ("3.65% Senior Notes") (collectively, "August 2017 Senior Notes Offering"). The Company intends to use the net proceeds of the August 2017 Senior Notes Offering to partially fund the Proposed Lightower Acquisition and pay related fees and expenses.

Common Stock Dividend

On August 3, 2017, the Company's board of directors declared a quarterly common stock cash dividend of $0.95 per share. The common stock dividend will be paid on September 29, 2017 to common stockholders of record as of September 15, 2017.