Long-Term Debt and Credit Facilities - Amended and Restated Credit Agreement (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Long-term Debt and Credit Facilities
Gain (loss) on extinguishment of debt	$ 8
Amended Credit Agreement | Minimum | Base Rate
Long-term Debt and Credit Facilities
Basis spread (as a percent)	1.50%
Amended Credit Agreement | Minimum | Eurodollar
Long-term Debt and Credit Facilities
Basis spread (as a percent)	0.50%
Amended Credit Agreement | Maximum | Base Rate
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.25%
Amended Credit Agreement | Maximum | Eurodollar
Long-term Debt and Credit Facilities
Basis spread (as a percent)	1.25%
Revolving Credit Facility | Revolving Credit Facility
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 2,200
Revolving Credit Facility | Revolving Credit Facility | CenturyLink Escrow, LLC | Swingline Loan
Long-term Debt and Credit Facilities
Maximum borrowing capacity	250
Revolving Credit Facility | Revolving Credit Facility | CenturyLink Escrow, LLC | Letter of Credit
Long-term Debt and Credit Facilities
Maximum borrowing capacity	800
Revolving Credit Facility | Term Loan A-1
Long-term Debt and Credit Facilities
Long-term debt, gross	300
Revolving Credit Facility | Term Loan B
Long-term Debt and Credit Facilities
Long-term debt, gross	4,900
Term Loan | Term Loan A
Long-term Debt and Credit Facilities
Long-term debt, gross	1,050
Senior Notes
Long-term Debt and Credit Facilities
Gain (loss) on extinguishment of debt		$ (109)
Senior Notes | Amended Credit Agreement
Long-term Debt and Credit Facilities
Gain (loss) on extinguishment of debt	$ 67	$ (67)
Senior Notes | Amended Credit Agreement, Term Loan B | Base Rate
Long-term Debt and Credit Facilities
Basis spread (as a percent)	1.25%
Senior Notes | Amended Credit Agreement, Term Loan B | Eurodollar
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.25%