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, 2022	Jun. 30, 2023	Mar. 31, 2023
Long-term Debt and Credit Facilities
Repayments of debt				$ 8,202
Senior notes | 5.800% Senior Notes due 2022 (at maturity)
Long-term Debt and Credit Facilities
Stated interest rate (as a percent)			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 (as a percent)	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 (as a percent)	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 (as a percent)	5.625%			5.625%	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 (as a percent)	7.20%			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 (as a percent)	5.125%	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 (as a percent)	6.875%			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 (as a percent)	5.375%			5.375%		5.375%
Repayments of debt	$ 494
Term Loan | Term Loan B
Long-term Debt and Credit Facilities
Repayments of debt	909
Term Loan | Scheduled Term Loan
Long-term Debt and Credit Facilities
Repayments of debt				$ 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 (as a percent)		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 (as a percent)		5.25%
Repayments of debt		$ 775
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 Capital Funding, Inc. | Senior notes
Long-term Debt and Credit Facilities
Repayments of debt	$ 63