Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 78	$ 39	$ 161	$ 109
Change related to retirement plan Amounts included in net periodic benefit cost for the period
Amortization of prior service cost	1	0	2	0
Comprehensive income	79	39	163	109
Less: Net income attributable to noncontrolling interests, net of tax	13	6	26	17
Comprehensive income attributable to TDS shareholders	$ 66	$ 33	$ 137	$ 92