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

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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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Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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The amount for notes payable (written promise to pay), due to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

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Long-Term Debt and Note Payable - Affiliate - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Aug. 07, 2020	Jun. 29, 2020	Jan. 15, 2020	Dec. 31, 2019	Sep. 30, 2017	Apr. 18, 2012
Long-term debt
Net loss on early retirement of debt	$ 19,000,000	$ 0
Note payable - affiliate	1,100,000,000					$ 1,069,000,000
Senior notes
Long-term debt
Net loss on early retirement of debt	(19,000,000)
Note payable - affiliate \| Affiliated entity
Long-term debt
Note payable - affiliate	$ 1,100,000,000					$ 1,069,000,000
Note payable - affiliate \| Qwest Corporation \| Affiliated entity
Long-term debt
Debt instrument, face amount							$ 965,000,000	$ 1,000,000,000.0
Weighted average interest rate	5.561%
Interest costs capitalized	$ 135,000,000
Accrued interest	$ 31,000,000
6.875% Notes Due 2033 \| Senior notes
Long-term debt
Repurchased face amount					$ 850,000,000
Stated interest rate					6.875%
7.125% Notes Due 2043 \| Senior notes
Long-term debt
Repurchased face amount					$ 250,000,000
Stated interest rate					7.125%
6.875% Notes Due 2054 \| Senior notes
Long-term debt
Repurchased face amount				$ 200,000,000
Stated interest rate				6.875%
6.875% Notes Due 2054 \| Senior notes \| Subsequent Event
Long-term debt
Repurchased face amount			$ 300,000,000
Stated interest rate			6.875%