Long-Term Debt and Credit Facilities - New Issuances (Details) - USD ($) $ in Millions	Jun. 15, 2021	Jan. 13, 2021	Dec. 31, 2021	Nov. 27, 2020	Aug. 12, 2020	Jun. 15, 2020	Jan. 24, 2020
Lumen Technologies, Inc. | Senior Notes | 6.450% Senior Notes, Series S, Due 2021
Long-term Debt and Credit Facilities
Stated interest rate	6.45%
Amount of debt redeemed	$ 1,200
Lumen Technologies, Inc. | Senior Notes | 5.375% Senior Notes Due 2029
Long-term Debt and Credit Facilities
Aggregate principal amount of debt issuance	$ 1,000
Stated interest rate	5.375%
Lumen Technologies, Inc. | Senior Notes | 4.500% Senior Notes Due 2029
Long-term Debt and Credit Facilities
Aggregate principal amount of debt issuance				$ 1,000
Stated interest rate				4.50%
Lumen Technologies, Inc. | Senior Notes | 4.000% Senior Secured Notes Due 2027
Long-term Debt and Credit Facilities
Aggregate principal amount of debt issuance							$ 1,250
Stated interest rate			4.00%				4.00%
Level 3 Financing, Inc. | Senior Notes
Long-term Debt and Credit Facilities
Amount of debt redeemed		$ 900
Level 3 Financing, Inc. | Senior Notes | 3.750% Sustainability-Linked Senior Notes 2029
Long-term Debt and Credit Facilities
Aggregate principal amount of debt issuance		$ 900
Stated interest rate		3.75%
Level 3 Financing, Inc. | Senior Notes | 3.625% Senior Notes Due 2029
Long-term Debt and Credit Facilities
Aggregate principal amount of debt issuance					$ 840
Stated interest rate					3.625%
Level 3 Financing, Inc. | Senior Notes | 4.250% Senior Secured Notes Due 2028
Long-term Debt and Credit Facilities
Aggregate principal amount of debt issuance						$ 1,200
Stated interest rate						4.25%