Fair Value Measurements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Book Value | Retail
Financial Instruments
Long-term debt	$ 1,500	$ 1,500
Book Value | Institutional
Financial Instruments
Long-term debt	536	535
Book Value | Other
Financial Instruments
Long-term debt	1,753	944
Fair Value | Level 2 | Retail
Financial Instruments
Long-term debt	899	1,594
Fair Value | Level 2 | Institutional
Financial Instruments
Long-term debt	395	659
Fair Value | Level 2 | Other
Financial Instruments
Long-term debt	$ 1,753	$ 944
6.7% Senior Notes | UScellular
Financial Instruments
Interest rate on debt	6.70%
Interest rate | Institutional and Other | Minimum
Financial Instruments
Fair value assumption, interest rate	3.52%	1.31%
Interest rate | Institutional and Other | Maximum
Financial Instruments
Fair value assumption, interest rate	8.28%	4.40%