Earnings Per Share - Computation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share, Basic [Abstract]
Net income attributable to UScellular shareholders	$ 54	$ 30	$ 155
Weighted average number of shares used in basic earnings per share (in shares)	85	85	86
Effects of dilutive securities (in shares)	2	1	1
Weighted average number of shares used in diluted earnings per share (in shares)	87	86	87
Basic earnings per share attributable to UScellular shareholders	$ 0.64	$ 0.35	$ 1.80
Diluted earnings per share attributable to UScellular shareholders	$ 0.63	$ 0.35	$ 1.77