Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 71	$ 83
Change related to retirement plan Amounts included in net periodic benefit cost for the period
Amortization of prior service cost	1	1
Comprehensive income	72	84
Less: Net income attributable to noncontrolling interests, net of tax	12	14
Comprehensive income attributable to TDS shareholders	$ 60	$ 70