Long-Term Debt and Credit Facilities - Schedule of Long Term Debt (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Long-term Debt and Credit Facilities
Finance lease and other obligations	$ 343	$ 347
Unamortized premiums, net	20	21
Unamortized debt issuance costs	(213)	(220)
Total long-term debt	28,553	28,982
Less current maturities	(156)	(1,554)
Long-term debt, excluding current maturities	28,397	27,428
Disposal Group, Held-for-sale, Not Discontinued Operations
Long-term Debt and Credit Facilities
Long-term debt, net of discounts	1,387	1,377
Lumen Technologies, Inc. | Credit facility | Revolving Credit Facility
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 1,200	$ 200
Long-term debt, weighted average interest rate	2.387%	2.103%
Lumen Technologies, Inc. | Credit facility | Revolving Credit Facility | LIBOR
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.00%
Lumen Technologies, Inc. | Term loan | Term Loan A
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 1,035	$ 1,050
Long-term debt, weighted average interest rate	2.457%	2.104%
Lumen Technologies, Inc. | Term loan | Term Loan A | LIBOR
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.00%
Lumen Technologies, Inc. | Term loan | Term Loan A-1
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 296	$ 300
Long-term debt, weighted average interest rate	2.457%	2.104%
Lumen Technologies, Inc. | Term loan | Term Loan A-1 | LIBOR
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.00%
Lumen Technologies, Inc. | Term loan | Term Loan B
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 4,888	$ 4,900
Long-term debt, weighted average interest rate	2.707%	2.354%
Lumen Technologies, Inc. | Term loan | Term Loan B | LIBOR
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.25%
Lumen Technologies, Inc. | Senior notes | 4.000% Senior Secured Notes Due 2027
Long-term Debt and Credit Facilities
Stated interest rate	4.00%
Long-term debt, gross	$ 1,250	$ 1,250
Lumen Technologies, Inc. | Senior notes | Senior Notes Maturing 2023-2042
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 7,014	8,414
Lumen Technologies, Inc. | Senior notes | Senior Notes Maturing 2023-2042 | Minimum
Long-term Debt and Credit Facilities
Stated interest rate	4.50%
Lumen Technologies, Inc. | Senior notes | Senior Notes Maturing 2023-2042 | Maximum
Long-term Debt and Credit Facilities
Stated interest rate	7.65%
Level 3 Financing, Inc. | Term loan | Tranche B 2027 Term Loan
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 3,111	$ 3,111
Long-term debt, weighted average interest rate	2.207%	1.854%
Level 3 Financing, Inc. | Term loan | Tranche B 2027 Term Loan | LIBOR
Long-term Debt and Credit Facilities
Basis spread (as a percent)	1.75%
Level 3 Financing, Inc. | Senior notes | Senior Notes, Maturing 2027-2029
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 1,500	$ 1,500
Level 3 Financing, Inc. | Senior notes | Senior Notes, Maturing 2027-2029 | Minimum
Long-term Debt and Credit Facilities
Stated interest rate	3.40%
Level 3 Financing, Inc. | Senior notes | Senior Notes, Maturing 2027-2029 | Maximum
Long-term Debt and Credit Facilities
Stated interest rate	3.875%
Level 3 Financing, Inc. | Senior notes | Senior Notes Maturing 2025-2029
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 5,515	$ 5,515
Level 3 Financing, Inc. | Senior notes | Senior Notes Maturing 2025-2029 | Minimum
Long-term Debt and Credit Facilities
Stated interest rate	3.625%
Level 3 Financing, Inc. | Senior notes | Senior Notes Maturing 2025-2029 | Maximum
Long-term Debt and Credit Facilities
Stated interest rate	5.375%
Embarq Corporation subsidiaries | Senior notes
Long-term Debt and Credit Facilities
Stated interest rate	7.995%	7.995%
Embarq Corporation subsidiaries | Senior notes | Disposal Group, Held-for-sale, Not Discontinued Operations
Long-term Debt and Credit Facilities
Long-term debt, net of discounts	$ 1,400	$ 1,400	$ 1,400
Embarq Corporation subsidiaries | First mortgage bonds
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 138	138
Embarq Corporation subsidiaries | First mortgage bonds | Minimum
Long-term Debt and Credit Facilities
Stated interest rate	7.125%
Embarq Corporation subsidiaries | First mortgage bonds | Maximum
Long-term Debt and Credit Facilities
Stated interest rate	8.375%
Qwest Corporation | Term loan
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 215	$ 215
Long-term debt, weighted average interest rate	2.46%	2.11%
Qwest Corporation | Term loan | LIBOR
Long-term Debt and Credit Facilities
Basis spread (as a percent)	2.00%
Qwest Corporation | Senior notes
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 1,986	$ 1,986
Qwest Corporation | Senior notes | Minimum
Long-term Debt and Credit Facilities
Stated interest rate	6.50%
Qwest Corporation | Senior notes | Maximum
Long-term Debt and Credit Facilities
Stated interest rate	7.75%
Qwest Capital Funding, Inc. | Senior notes
Long-term Debt and Credit Facilities
Long-term debt, gross	$ 255	$ 255
Qwest Capital Funding, Inc. | Senior notes | Minimum
Long-term Debt and Credit Facilities
Stated interest rate	6.875%
Qwest Capital Funding, Inc. | Senior notes | Maximum
Long-term Debt and Credit Facilities
Stated interest rate	7.75%