Long-Term Debt and Credit Facilities - Schedule of Debt Repayments (Details) - USD ($) $ in Millions	3 Months Ended							12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Jun. 15, 2021
Long-term Debt and Credit Facilities
Repayments of debt								$ 8,202	$ 3,538
Senior notes | 5.800% Senior Notes due 2022 (at maturity)
Long-term Debt and Credit Facilities
Stated interest rate			5.80%
Repayments of debt			$ 1,400
Senior notes | 6.750% Senior Notes, Series W, due 2023
Long-term Debt and Credit Facilities
Stated interest rate	6.75%							6.75%
Repayments of debt	$ 750
Senior notes | 7.500% Senior Notes, Series Y, due 2024
Long-term Debt and Credit Facilities
Stated interest rate	7.50%	7.50%						7.50%
Repayments of debt	$ 982	$ 18
Senior notes | 5.625% Senior Notes, Series X, due 2025
Long-term Debt and Credit Facilities
Stated interest rate	5.625%							5.625%
Repayments of debt	$ 286
Senior notes | 7.200% Senior Notes, Series D, due 2025
Long-term Debt and Credit Facilities
Stated interest rate	7.20%							7.20%
Repayments of debt	$ 34
Senior notes | 5.125% Senior Notes due 2026
Long-term Debt and Credit Facilities
Stated interest rate	5.125%	5.125%						5.125%
Repayments of debt	$ 520	$ 11
Senior notes | 6.875% Debentures, Series G, due 2028
Long-term Debt and Credit Facilities
Stated interest rate	6.875%							6.875%
Repayments of debt	$ 130
Senior notes | 5.375% Senior Notes due 2029
Long-term Debt and Credit Facilities
Stated interest rate	5.375%							5.375%
Repayments of debt	$ 494
Senior notes | 6.450% Senior Notes, Series S, due 2021 (at maturity)
Long-term Debt and Credit Facilities
Stated interest rate						6.45%				6.45%
Repayments of debt						$ 1,231
Term loan | Term Loan B
Long-term Debt and Credit Facilities
Repayments of debt	909
Term loan | Scheduled term loan payments
Long-term Debt and Credit Facilities
Repayments of debt								$ 125	$ 125
Other
Long-term Debt and Credit Facilities
Repayments of debt	68
Level 3 Financing, Inc. | Senior notes | 5.375% Senior Notes due 2025
Long-term Debt and Credit Facilities
Stated interest rate		5.375%
Repayments of debt		$ 800
Level 3 Financing, Inc. | Senior notes | 5.250% Senior Notes due 2026
Long-term Debt and Credit Facilities
Stated interest rate		5.25%
Repayments of debt		$ 775
Level 3 Financing, Inc. | Senior notes | 5.375% Senior Notes due 2024
Long-term Debt and Credit Facilities
Stated interest rate							5.375%
Repayments of debt							$ 900
Level 3 Financing, Inc. | Term loan | Tranche B 2027 Term Loan
Long-term Debt and Credit Facilities
Repayments of debt		$ 700
Embarq Corporation Subsidiaries | First mortgage bonds | First Mortgage Bonds
Long-term Debt and Credit Facilities
Repayments of debt	137
Qwest Corporation, Inc. | Senior notes | 6.750% Senior Notes (at maturity)
Long-term Debt and Credit Facilities
Stated interest rate				6.75%					6.75%
Repayments of debt				$ 950
Qwest Corporation, Inc. | Senior notes | 7.000% Senior Notes due 2056
Long-term Debt and Credit Facilities
Stated interest rate							7.00%
Repayments of debt							$ 235
Qwest Capital Funding, Inc. | Senior notes
Long-term Debt and Credit Facilities
Repayments of debt	$ 63				$ 97