Products and Services Revenue - Additional Information (Details)	9 Months Ended
Sep. 30, 2019 category
Revenue from Contract with Customer [Abstract]
Number of categories of products and services	6

Represents the number of categories in which the entity categorizes the products and services.

No definition available.

Name:	ctl_NumberOfCategoriesOfProductsAndServices
Namespace Prefix:	ctl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration