Earnings Per Share - Reconciliation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings per share
Net income attributable to TDS shareholders used in basic earnings per share	$ 33	$ 33	$ 92	$ 72
Noncontrolling interest adjustment	(1)	(1)	(1)	(1)
Net income attributable to TDS shareholders used in diluted earnings per share	$ 32	$ 32	$ 91	$ 71
Weighted average number of shares used in basic earnings per share (in shares)	114	112	114	112
Effects of dilutive securities (in shares)	2	1	2	1
Weighted average number of shares used in diluted earnings per share (in shares)	116	113	116	113
Basic earnings per share attributable to TDS shareholders (in dollars per share)	$ 0.29	$ 0.30	$ 0.81	$ 0.65
Diluted earnings per share attributable to TDS shareholders (in dollars per share)	$ 0.28	$ 0.29	$ 0.78	$ 0.63
Common Shares
Earnings per share
Weighted average number of shares used in basic earnings per share (in shares)	107	105	107	105
Series A Common Shares
Earnings per share
Weighted average number of shares used in basic earnings per share (in shares)	7	7	7	7