Revenue Recognition - Disaggregation Of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 3,805	$ 4,076	$ 4,039
Out-of-period adjustment
Disaggregation of Revenue [Line Items]
Immaterial error correction	UScellular recorded an adjustment to correct a prior period error related to the recognition of discounts for certain Prepaid customers, which decreased Service revenue by $5 million in 2023. This adjustment was not material to any of the periods impacted.		UScellular recorded an adjustment to correct a prior period error related to the timing of recognition of regulatory fee billings, which increased Service revenue by $9 million in 2021. This adjustment was not material to any of the periods impacted.
Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 2,943	3,032	$ 3,032
Transferred over time | Retail service
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	2,742	2,793	2,757
Transferred over time | Retail service | Out-of-period adjustment
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	(5)		9
Transferred over time | Retail service | Revision of Prior Period, Reclassification, Adjustment
Disaggregation of Revenue [Line Items]
Revenue from contract with customers			(8)
Transferred over time | Inbound roaming
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	32	67	110
Transferred over time | Other service
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	169	172	165
Transferred over time | Other service | Revision of Prior Period, Reclassification, Adjustment
Disaggregation of Revenue [Line Items]
Revenue from contract with customers			8
Transferred at point in time | Equipment sales
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 862	$ 1,044	$ 1,007