Acquisition of Level 3	9 Months Ended
Sep. 30, 2017
Business Combinations [Abstract]
Business Combination Disclosure	Acquisition of Level 3 On November 1, 2017, CenturyLink acquired Level 3 through successive merger transactions, including a merger of Level 3 with and into a merger subsidiary, which survived such merger as our indirect wholly-owned subsidiary under the name of Level 3 Parent, LLC. As a result of the acquisition, Level 3 shareholders received $26.50 per share in cash and 1.4286 shares of CenturyLink common stock, with cash paid in lieu of fractional shares, for each outstanding share of Level 3 common stock they owned at closing, subject to certain limited exceptions. Upon closing, CenturyLink shareholders owned approximately 51% and Level 3 shareholders owned approximately 49% of the combined company. At closing, we assumed Level 3's long-term debt of approximately $11 billion. In addition, 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 CenturyLink 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 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 CenturyLink, Inc. restricted stock unit award using a ratio of 2.8386 to 1 as determined in accordance with a formula set forth in the merger agreement. The consideration for this acquisition included $9.6 billion in cash payments and approximately 517 million shares of CenturyLink common stock (valued at $9.8 billion based on the $18.99 closing price of our stock on October 31, 2017) issued to Level 3 stockholders at closing. Our final determination of aggregate consideration will also include the estimated fair value of the pre-combination portion of certain assumed share-based compensation awards. The premium paid by CenturyLink in this transaction is attributable to strategic benefits, including enhanced financial and operational scale, market diversification and improved networks. None of the goodwill associated with this transaction is deductible for income tax purposes. The aggregate cash payments required to be paid on or about the closing date were funded with the proceeds of $7.945 billion of term loans and $400 million of funds borrowed under our new revolving credit facility discussed further herein, together with other available funds, which included $1.825 billion of Level 3 Parent, LLC's available funds. For additional information regarding CenturyLink’s financing of the Level 3 acquisition see Note 4—Long-Term Debt and Credit Facilities. Following the Level 3 acquisition, (i) Standard and Poor's downgraded CenturyLink, Inc.'s current unsecured long-term debt rating to B+ (with a stable outlook); (ii) Moody's Investors Services downgraded CenturyLink, Inc.'s current unsecured long-term debt rating to B2 (with a negative outlook); and (iii) Fitch's Ratings downgraded CenturyLink, Inc.'s current unsecured long-term debt rating to BB (with a stable outlook). Also subsequent to the Level 3 acquisition, (i) Standard and Poor's rated CenturyLink, Inc.'s new secured long-term debt at BBB- (with a stable outlook); (ii) Moody's Investors Services rated CenturyLink, Inc.'s new secured long-term debt at Ba3 (with a negative outlook); and (iii) Fitch's Ratings rated CenturyLink, Inc.'s new secured long-term debt at BB+ (with a stable outlook). Following the Level 3 acquisition, Qwest Corporation's current unsecured senior debt rating of Ba1 was downgraded to Ba2 with a negative outlook by Moody's Investors Service, Inc., and its current unsecured senior debt rating of BBB- was downgraded to BB+ with a stable outlook by Fitch Ratings. Standard and Poor's reaffirmed its rating of BBB- with a stable outlook for Qwest Corporation's current unsecured senior debt. The consolidated results of operations of Level 3 will be included in our consolidated results of operations beginning November 1, 2017. The assets acquired and liabilities assumed of Level 3 will be recognized at their estimated acquisition date fair values. The estimation of such fair values and the related estimation of lives of depreciable tangible assets and amortizable intangible assets will require significant judgment. Due to the timing of the Level 3 acquisition, as of the date of this report, we cannot yet make with reasonable accuracy estimates of certain components of the aggregate acquisition consideration and the fair values of assets acquired and liabilities assumed. The final determinations of aggregate acquisition consideration and our estimates of acquisition date fair value will be determined based in part upon an analysis, which is expected to be completed in 2018. As of September 30, 2017, we had recognized approximately $70 million in cumulative merger-related transaction costs, including investment banker and legal fees. In the first half of 2017, we granted less than 1 million shares of restricted stock and approximately $21 million of deferred cash compensation awards to certain executive officers and other key employees as part of a retention program in connection with our acquisition of Level 3. The shares of restricted stock will vest in equal installments on the first, second and third anniversaries of the merger closing date. Each employee receiving a deferred cash award is expected to receive one-half of the award no later than 15 days after the closing date and receive the other half on the one year anniversary of the merger closing date, subject to continued employment with us. Both the restricted stock grant and the deferred cash award will accelerate if we terminate the recipient without cause or under certain other conditions. During the nine months ended September 30, 2017, we recorded compensation expense of $17 million related to this retention program (which does not reflect compensation expense separately incurred by Level 3 under its distinct retention plan).

Acquisition of Level 3

On November 1, 2017, CenturyLink acquired Level 3 through successive merger transactions, including a merger of Level 3 with and into a merger subsidiary, which survived such merger as our indirect wholly-owned subsidiary under the name of Level 3 Parent, LLC. As a result of the acquisition, Level 3 shareholders received $26.50 per share in cash and 1.4286 shares of CenturyLink common stock, with cash paid in lieu of fractional shares, for each outstanding share of Level 3 common stock they owned at closing, subject to certain limited exceptions. Upon closing, CenturyLink shareholders owned approximately 51% and Level 3 shareholders owned approximately 49% of the combined company. At closing, we assumed Level 3's long-term debt of approximately $11 billion.

In addition, 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 CenturyLink 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 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 CenturyLink, Inc. restricted stock unit award using a ratio of 2.8386 to 1 as determined in accordance with a formula set forth in the merger agreement.

The consideration for this acquisition included $9.6 billion in cash payments and approximately 517 million shares of CenturyLink common stock (valued at $9.8 billion based on the $18.99 closing price of our stock on October 31, 2017) issued to Level 3 stockholders at closing. Our final determination of aggregate consideration will also include the estimated fair value of the pre-combination portion of certain assumed share-based compensation awards. The premium paid by CenturyLink in this transaction is attributable to strategic benefits, including enhanced financial and operational scale, market diversification and improved networks. None of the goodwill associated with this transaction is deductible for income tax purposes.

The aggregate cash payments required to be paid on or about the closing date were funded with the proceeds of $7.945 billion of term loans and $400 million of funds borrowed under our new revolving credit facility discussed further herein, together with other available funds, which included $1.825 billion of Level 3 Parent, LLC's available funds. For additional information regarding CenturyLink’s financing of the Level 3 acquisition see Note 4—Long-Term Debt and Credit Facilities.

Following the Level 3 acquisition, (i) Standard and Poor's downgraded CenturyLink, Inc.'s current unsecured long-term debt rating to B+ (with a stable outlook); (ii) Moody's Investors Services downgraded CenturyLink, Inc.'s current unsecured long-term debt rating to B2 (with a negative outlook); and (iii) Fitch's Ratings downgraded CenturyLink, Inc.'s current unsecured long-term debt rating to BB (with a stable outlook). Also subsequent to the Level 3 acquisition, (i) Standard and Poor's rated CenturyLink, Inc.'s new secured long-term debt at BBB- (with a stable outlook); (ii) Moody's Investors Services rated CenturyLink, Inc.'s new secured long-term debt at Ba3 (with a negative outlook); and (iii) Fitch's Ratings rated CenturyLink, Inc.'s new secured long-term debt at BB+ (with a stable outlook).

Following the Level 3 acquisition, Qwest Corporation's current unsecured senior debt rating of Ba1 was downgraded to Ba2 with a negative outlook by Moody's Investors Service, Inc., and its current unsecured senior debt rating of BBB- was downgraded to BB+ with a stable outlook by Fitch Ratings. Standard and Poor's reaffirmed its rating of BBB- with a stable outlook for Qwest Corporation's current unsecured senior debt.

The consolidated results of operations of Level 3 will be included in our consolidated results of operations beginning November 1, 2017. The assets acquired and liabilities assumed of Level 3 will be recognized at their estimated acquisition date fair values. The estimation of such fair values and the related estimation of lives of depreciable tangible assets and amortizable intangible assets will require significant judgment. Due to the timing of the Level 3 acquisition, as of the date of this report, we cannot yet make with reasonable accuracy estimates of certain components of the aggregate acquisition consideration and the fair values of assets acquired and liabilities assumed. The final determinations of aggregate acquisition consideration and our estimates of acquisition date fair value will be determined based in part upon an analysis, which is expected to be completed in 2018.

As of September 30, 2017, we had recognized approximately $70 million in cumulative merger-related transaction costs, including investment banker and legal fees.

In the first half of 2017, we granted less than 1 million shares of restricted stock and approximately $21 million of deferred cash compensation awards to certain executive officers and other key employees as part of a retention program in connection with our acquisition of Level 3. The shares of restricted stock will vest in equal installments on the first, second and third anniversaries of the merger closing date. Each employee receiving a deferred cash award is expected to receive one-half of the award no later than 15 days after the closing date and receive the other half on the one year anniversary of the merger closing date, subject to continued employment with us. Both the restricted stock grant and the deferred cash award will accelerate if we terminate the recipient without cause or under certain other conditions. During the nine months ended September 30, 2017, we recorded compensation expense of $17 million related to this retention program (which does not reflect compensation expense separately incurred by Level 3 under its distinct retention plan).