Leases (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021 USD ($) property	Sep. 30, 2021 USD ($)
Leases [Abstract]
Number of ceased properties \| property	13
Accelerated lease costs \| $	$ 15	$ 15

Lessee, Operating Lease, Number Of Ceased Properties

No definition available.

Name:	lumn_LesseeOperatingLeaseNumberOfCeasedProperties
Namespace Prefix:	lumn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration