Earnings Per Share - Reconciliation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings per share
Net income attributable to TDS common shareholders used in basic earnings per share	$ 57	$ 69
Noncontrolling interest adjustment	(1)	(1)
Net income attributable to TDS common shareholders used in diluted earnings per share	$ 56	$ 68
Weighted average number of shares used in basic earnings per share (in shares)	114	115
Effects of dilutive securities (in shares)	2	1
Weighted average number of shares used in diluted earnings per share (in shares)	116	116
Basic earnings per share attributable to TDS common shareholders (in dollars per share)	$ 0.49	$ 0.60
Diluted earnings per share attributable to TDS common shareholders (in dollars per share)	$ 0.48	$ 0.59
Common Shares
Earnings per share
Weighted average number of shares used in basic earnings per share (in shares)	107	108
Series A Common Shares
Earnings per share
Weighted average number of shares used in basic earnings per share (in shares)	7	7