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 contracts with customers	$ 5,033	$ 5,293	$ 5,220
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 contracts with customers	$ 4,042	4,120	$ 4,107
Transferred over time | Retail service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,742	2,793	2,757
Transferred over time | Inbound roaming
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	32	67	110
Transferred over time | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	700	669	641
Transferred over time | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	155	173	183
Transferred over time | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	169	173	178
Transferred over time | Other service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	244	245	238
Transferred at point in time | Equipment and product sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	991	1,173	1,113
UScellular
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,805	4,076	4,039
UScellular | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,943	3,032	3,032
UScellular | Transferred over time | Retail service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,742	2,793	2,757
UScellular | Transferred over time | Retail service | Prior period reclassification
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			(8)
UScellular | Transferred over time | Retail service | Out-of-period adjustment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(5)		9
UScellular | Transferred over time | Inbound roaming
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	32	67	110
UScellular | Transferred over time | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
UScellular | Transferred over time | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
UScellular | Transferred over time | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
UScellular | Transferred over time | Other service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	169	172	165
UScellular | Transferred over time | Other service | Prior period reclassification
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			8
UScellular | Transferred at point in time | Equipment and product sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	862	1,044	1,007
TDS Telecom
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,025	1,016	1,003
TDS Telecom | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,024	1,015	1,002
TDS Telecom | Transferred over time | Retail service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
TDS Telecom | Transferred over time | Inbound roaming
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
TDS Telecom | Transferred over time | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	700	669	641
TDS Telecom | Transferred over time | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	155	173	183
TDS Telecom | Transferred over time | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	169	173	178
TDS Telecom | Transferred over time | Other service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
TDS Telecom | Transferred at point in time | Equipment and product sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1	1	1
Corporate, Eliminations and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	203	201	178
Corporate, Eliminations and Other | Transferred over time
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	75	73	73
Corporate, Eliminations and Other | Transferred over time | Retail service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
Corporate, Eliminations and Other | Transferred over time | Inbound roaming
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
Corporate, Eliminations and Other | Transferred over time | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
Corporate, Eliminations and Other | Transferred over time | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
Corporate, Eliminations and Other | Transferred over time | Wholesale
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0	0
Corporate, Eliminations and Other | Transferred over time | Other service
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	75	73	73
Corporate, Eliminations and Other | Transferred at point in time | Equipment and product sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 128	$ 128	$ 105