Events Associated with the CenturyLink Merger	9 Months Ended
Sep. 30, 2017
Business Combinations [Abstract]
Events Associated with the CenturyLink Merger	(2) Events Associated with the CenturyLink Merger On November 1, 2017, pursuant to the terms and conditions of the previously-announced Merger Agreement, dated as of October 31, 2016, among Level 3, CenturyLink, Merger Sub I and Merger Sub 2, Merger Sub 1 merged with and into Level 3 (the “Initial Merger”) and immediately thereafter Level 3 merged with and into Merger Sub 2 (the “Subsequent Merger”), with Merger Sub 2 surviving such merger as an indirect wholly owned subsidiary of CenturyLink under the name of Level 3 Parent, LLC. In connection with the Initial Merger, each outstanding share of Level 3 Communications, Inc. common stock, par value $0.01 per share (the “LVLT Common Stock”), other than shares held by holders who have properly exercised appraisal rights and shares owned by CenturyLink, Level 3 or their respective subsidiaries, was converted into the right to receive $26.50 in cash, without interest, and 1.4286 shares of CenturyLink common stock, par value $1.00 per share (“CTL Common Stock”), with cash paid in lieu of fractional shares. In addition, as a result of the Initial Merger, (i) each outstanding Level 3 restricted stock unit award granted prior to April 1, 2014 or granted to an outside director of Level 3 was converted into the right to receive $26.50 in cash and 1.4286 shares of CTL Common Stock (and cash in lieu of fractional shares) with respect to each Level 3 share covered by such award, less applicable tax withholdings, and (ii) each outstanding Level 3 restricted stock unit award granted on or after April 1, 2014 (other than those granted to outside directors of Level 3) was converted into a restricted stock unit award relating to such number of shares of CTL Common Stock determined in accordance with a formula set forth in the Merger Agreement (the “Continuing RSU Awards”). The Continuing RSU Awards will remain subject to the same terms and conditions applicable to the original Level 3 awards immediately prior to their conversion, subject to certain exceptions. As a result of the Initial Merger, CenturyLink delivered to our stockholders an aggregate of approximately $9.6 billion in cash and approximately 517.3 million shares of CTL Common Stock valued at approximately $9.8 billion (excluding shares of CTL Common Stock subject to future issuance under the Continuing RSU Awards and amounts to be paid to holders of dissenting shares), based on the number of shares of LVLT Common Stock and Converted RSU Awards outstanding at the close of business on October 31, 2017 and the per share closing price of CTL Common Stock on the New York Stock Exchange on October 31, 2017. The above-described issuance of shares of CTL Common Stock in connection with the Initial Merger was registered under the Securities Act of 1933, as amended, pursuant to a registration statement on Form S-4 (File No. 333-215121) filed by us with the U.S. Securities and Exchange Commission (the “Commission”) and declared effective on February 13, 2017. The joint proxy statement/prospectus of CenturyLink and Level 3 included in the registration statement (the “Joint Proxy Statement/Prospectus”), including the various reports incorporated by reference therein, contains additional information about the above-described transactions. In connection with the closing of the Merger Agreement, we invested $1.825 billion in CenturyLink in exchange for an unsecured demand note that bears interest at 3.5% per annum. The principal amount of such note is payable upon demand by Level 3 Parent but no later than November 1, 2020, and is prepayable by CenturyLink at any time. The U.S. Department of Justice approved the acquisition subject to conditions of a consent decree on October 2, 2017, which requires the combined company to divest certain Level 3 metro network assets in the markets located in Albuquerque, New Mexico; Boise, Idaho; and Tucson, Arizona and the combined company will divest 24 strands of dark fiber connecting 30 specified city-pairs across the United States in the form of an Indefeasible Right of Use agreement. The carrying value of the metro network and dark fiber assets is not material to Level 3. Our results of operations will be included in the consolidated results of operations of CenturyLink beginning November 1, 2017. CenturyLink will account for its acquisition of us under the acquisition method of accounting, which will result in the allocation of the purchase price to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition, with the excess purchase price being recognized as goodwill. None of the goodwill associated with this transaction is deductible for income tax purposes. The allocation of the purchase price to the assets acquired and liabilities assumed (and the related estimated lives of depreciable tangible and identifiable intangible assets) will require a significant amount of judgment. Such allocation of the purchase price (including the assignment of goodwill to reporting units) will be determined based upon an analysis currently being performed, which is expected to be complete no later than the fourth quarter of 2018. The recognition of assets and liabilities at fair value will be reflected in our financial statements and therefore will result in a new basis of accounting for the “successor period” beginning on November 1, 2017. This new basis of accounting means that our financial statements for the successor periods will not be comparable to our previously reported financial statements, including the financial statements in this report. We recognized $31 million and $74 million of expenses associated with our activities surrounding the CenturyLink Merger for the three and nine months ended September 30, 2017, respectively.

(2) Events Associated with the CenturyLink Merger

On November 1, 2017, pursuant to the terms and conditions of the previously-announced Merger Agreement, dated as of October 31, 2016, among Level 3, CenturyLink, Merger Sub I and Merger Sub 2, Merger Sub 1 merged with and into Level 3 (the “Initial Merger”) and immediately thereafter Level 3 merged with and into Merger Sub 2 (the “Subsequent Merger”), with Merger Sub 2 surviving such merger as an indirect wholly owned subsidiary of CenturyLink under the name of Level 3 Parent, LLC.

In connection with the Initial Merger, each outstanding share of Level 3 Communications, Inc. common stock, par value $0.01 per share (the “LVLT Common Stock”), other than shares held by holders who have properly exercised appraisal rights and shares owned by CenturyLink, Level 3 or their respective subsidiaries, was converted into the right to receive $26.50 in cash, without interest, and 1.4286 shares of CenturyLink common stock, par value $1.00 per share (“CTL Common Stock”), with cash paid in lieu of fractional shares.

In addition, as a result of the Initial Merger, (i) each outstanding Level 3 restricted stock unit award granted prior to April 1, 2014 or granted to an outside director of Level 3 was converted into the right to receive $26.50 in cash and 1.4286 shares of CTL Common Stock (and cash in lieu of fractional shares) with respect to each Level 3 share covered by such award, less applicable tax withholdings, and (ii) each outstanding Level 3 restricted stock unit award granted on or after April 1, 2014 (other than those granted to outside directors of Level 3) was converted into a restricted stock unit award relating to such number of shares of CTL Common Stock determined in accordance with a formula set forth in the Merger Agreement (the “Continuing RSU Awards”). The Continuing RSU Awards will remain subject to the same terms and conditions applicable to the original Level 3 awards immediately prior to their conversion, subject to certain exceptions.

As a result of the Initial Merger, CenturyLink delivered to our stockholders an aggregate of approximately $9.6 billion in cash and approximately 517.3 million shares of CTL Common Stock valued at approximately $9.8 billion (excluding shares of CTL Common Stock subject to future issuance under the Continuing RSU Awards and amounts to be paid to holders of dissenting shares), based on the number of shares of LVLT Common Stock and Converted RSU Awards outstanding at the close of business on October 31, 2017 and the per share closing price of CTL Common Stock on the New York Stock Exchange on October 31, 2017.

The above-described issuance of shares of CTL Common Stock in connection with the Initial Merger was registered under the Securities Act of 1933, as amended, pursuant to a registration statement on Form S-4 (File No. 333-215121) filed by us with the U.S. Securities and Exchange Commission (the “Commission”) and declared effective on February 13, 2017. The joint proxy statement/prospectus of CenturyLink and Level 3 included in the registration statement (the “Joint Proxy Statement/Prospectus”), including the various reports incorporated by reference therein, contains additional information about the above-described transactions.

In connection with the closing of the Merger Agreement, we invested $1.825 billion in CenturyLink in exchange for an unsecured demand note that bears interest at 3.5% per annum. The principal amount of such note is payable upon demand by Level 3 Parent but no later than November 1, 2020, and is prepayable by CenturyLink at any time.

The U.S. Department of Justice approved the acquisition subject to conditions of a consent decree on October 2, 2017, which requires the combined company to divest certain Level 3 metro network assets in the markets located in Albuquerque, New Mexico; Boise, Idaho; and Tucson, Arizona and the combined company will divest 24 strands of dark fiber connecting 30 specified city-pairs across the United States in the form of an Indefeasible Right of Use agreement. The carrying value of the metro network and dark fiber assets is not material to Level 3.

Our results of operations will be included in the consolidated results of operations of CenturyLink beginning November 1, 2017. CenturyLink will account for its acquisition of us under the acquisition method of accounting, which will result in the allocation of the purchase price to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition, with the excess purchase price being recognized as goodwill. None of the goodwill associated with this transaction is deductible for income tax purposes. The allocation of the purchase price to the assets acquired and liabilities assumed (and the related estimated lives of depreciable tangible and identifiable intangible assets) will require a significant amount of judgment. Such allocation of the purchase price (including the assignment of goodwill to reporting units) will be determined based upon an analysis currently being performed, which is expected to be complete no later than the fourth quarter of 2018. The recognition of assets and liabilities at fair value will be reflected in our financial statements and therefore will result in a new basis of accounting for the “successor period” beginning on November 1, 2017. This new basis of accounting means that our financial statements for the successor periods will not be comparable to our previously reported financial statements, including the financial statements in this report.

We recognized $31 million and $74 million of expenses associated with our activities surrounding the CenturyLink Merger for the three and nine months ended September 30, 2017, respectively.