The face amount of the over-allotment sold during a debt issuance.

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Represents the ratio of debt to EBITDA (i.e. earnings before interest, taxes, depreciation and amortization, as defined in the CenturyLink, Inc.'s Credit Facility) to be maintained under the term loan covenant.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Description of debt redemption features under terms of the debt agreement.

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Face (par) amount of the original debt instrument that was repurchased.

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No definition available.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Amount of interest capitalized during the period.

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Total interest costs incurred during the period and either capitalized or charged against earnings.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount of interest expense incurred on a debt or other obligation to related party.

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The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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Long-Term Debt and Revolving Promissory Note (Details 2) $ in Millions								12 Months Ended
	May 05, 2017 USD ($)	Apr. 28, 2017 USD ($)	Sep. 15, 2016 USD ($)	Aug. 29, 2016 USD ($)	Aug. 22, 2016 USD ($)	Jan. 29, 2016 USD ($)	Feb. 20, 2015 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2017 USD ($)	May 08, 2017 USD ($)	May 04, 2017 USD ($)	May 02, 2016 USD ($)
Debt instruments
Net loss on early retirement of debt								$ 5	$ 27	$ 0
Long-term debt, gross								7,430
Amount of gross interest expense, net of capitalized interest and interest expense - affiliates
Gross interest expense								497	497	491
Capitalized interest								(32)	(19)	(18)
Total interest expense								465	478	473
Interest expense-affiliates, net								63	59	$ 53
Qwest Corporation \| Senior notes
Debt instruments
Long-term debt, gross								$ 7,294	7,259
Qwest Corporation \| Senior notes \| Minimum
Debt instruments
Interest rate, stated percentage (as a percent)								6.125%
Qwest Corporation \| Senior notes \| Maximum
Debt instruments
Interest rate, stated percentage (as a percent)								7.75%
Qwest Corporation \| Term loan
Debt instruments
Interest rate, stated percentage (as a percent)								3.57%
Long-term debt, gross								$ 100	100
Qwest Corporation \| 6.75% Notes due 2057 \| Senior notes
Debt instruments
Face amount of debt instrument	$ 85	$ 575
Interest rate, stated percentage (as a percent)		6.75%
Net proceeds from issuance of debt	$ 638
Qwest Corporation \| 6.75% Notes due 2057 \| Senior notes \| Debt instrument, redemption period one
Debt instruments
Debt instrument redemption description		redeemed by Qwest Corporation, in whole or in part, on or after June 15, 2022, at a redemption price equal to 100% of the principal amount
Qwest Corporation \| 6.5% Notes due 2056 \| Senior notes
Debt instruments
Face amount of debt instrument					$ 978
Interest rate, stated percentage (as a percent)					6.50%
Debt instrument face amount over-allotment					$ 128
Net proceeds from issuance of debt					$ 946
Qwest Corporation \| 6.5% Notes due 2056 \| Senior notes \| Debt instrument, redemption period one
Debt instruments
Debt instrument redemption description					on or after September 1, 2021, at a redemption price equal to 100% of the principal amount redeemed
Qwest Corporation \| 7.00% Notes due 2056 \| Senior notes
Debt instruments
Face amount of debt instrument						$ 235
Interest rate, stated percentage (as a percent)						7.00%
Net proceeds from issuance of debt						$ 227
Qwest Corporation \| 7.00% Notes due 2056 \| Senior notes \| Debt instrument, redemption period one
Debt instruments
Debt instrument redemption description						on or after February 1, 2021, at a redemption price equal to 100% of the principal amount redeemed
Qwest Corporation \| 7.5% Notes due 2051 \| Senior notes
Debt instruments
Face amount of debt instrument												$ 288
Interest rate, stated percentage (as a percent)			7.50%									7.50%
Repurchased face amount of Senior notes			$ 287									$ 125
Net loss on early retirement of debt			$ 9
Qwest Corporation \| 6.5% Notes due 2017 \| Senior notes
Debt instruments
Interest rate, stated percentage (as a percent)													6.50%
Repurchased face amount of Senior notes													$ 500
Qwest Corporation \| 7.375% Notes due 2051 \| Senior notes
Debt instruments
Interest rate, stated percentage (as a percent)				7.375%
Repurchased face amount of Senior notes				$ 661
Net loss on early retirement of debt				$ 18
Qwest Corporation \| 8.375% Notes due 2016 \| Senior notes
Debt instruments
Interest rate, stated percentage (as a percent)														8.375%
Repurchased face amount of Senior notes														$ 235
Qwest Corporation \| Term Loan \| Term loan
Debt instruments
Face amount of debt instrument							$ 100
Long-term debt, gross								$ 100	$ 100
Term Loan covenant Debt to EBITDA Ratio								2.85
Qwest Corporation \| Term Loan \| Term loan \| Minimum \| London Interbank Offered Rate (LIBOR)
Debt instruments
Interest rate margin (as a percent)							1.50%
Qwest Corporation \| Term Loan \| Term loan \| Minimum \| Base Rate
Debt instruments
Interest rate margin (as a percent)							0.50%
Qwest Corporation \| Term Loan \| Term loan \| Maximum \| London Interbank Offered Rate (LIBOR)
Debt instruments
Interest rate margin (as a percent)							2.50%
Qwest Corporation \| Term Loan \| Term loan \| Maximum \| Base Rate
Debt instruments
Interest rate margin (as a percent)							1.50%
CenturyLink, Inc. affiliate \| Qwest Corporation \| Revolving promissory note
Debt instruments
Face amount of debt instrument											$ 965