Products and Services Revenue - Additional Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($) category	Mar. 31, 2018 USD ($)
Revenue from Contract with Customer [Abstract]
Number of categories of products and services \| category	6
Universal service funds taxes and surcharges \| $	$ 30	$ 34

Represents the taxes and surcharges on revenues from universal service funds (USF), which are included in operating revenues and expenses.

No definition available.

Name:	ctl_UniversalServiceFundsTaxesAndSurcharges
Namespace Prefix:	ctl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration