Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Amounts recorded gross in revenues that are billed to customers and remitted to governmental authorities	$ 11	$ 17

The total Universal Service Funds and other surcharges recorded gross in revenues that are billed to customers and remitted to governmental authorities.

No definition available.

Name:	usm_AmountsCollectedAndRemittedToGovernmentalAuthorities
Namespace Prefix:	usm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration