Basis of Presentation - Narrative (Details) - USD ($)		3 Months Ended				9 Months Ended
	Jan. 01, 2018	Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2018		Sep. 30, 2017
Basis of Presentation [Line Items]
Adjustment to depreciation, amortization and accretion as a result of change in accounting estimate		$ 220,000,000		$ 209,000,000		$ 662,000,000		$ 632,000,000
Net income (loss)		$ 53,000,000	[1]	$ (231,000,000)		$ 155,000,000	[1]	$ (176,000,000)
Adjustment to basic earnings per share available to TDS common shareholders due to change in accounting estimate (in dollars per share)		$ 0.41		$ (1.64)		$ 1.06		$ (1.21)
Adjustment to diluted earnings (loss) per share available to TDS common shareholders due to change in accounting estimate (in dollars per share)		$ 0.41		$ (1.64)		$ 1.04		$ (1.21)
Adjustment to selling, general and administrative as a result of adoption of new accounting guidance		$ 421,000,000	[1]	$ 423,000,000		$ 1,232,000,000	[1]	$ 1,249,000,000
Adjustment to other, net income as a result of adoption of new accounting pronouncements		2,000,000		1,000,000	[2]	1,000,000		3,000,000	[2]
Adjustment to income (loss) before income taxes due to adoption of new accounting guidance		58,000,000	[1]	(236,000,000)		203,000,000	[1]	(137,000,000)
Amounts recorded gross in revenues that are billed to customers and remitted to governmental authorities		22,000,000		20,000,000		$ 67,000,000		58,000,000
ASU 2017-07
Basis of Presentation [Line Items]
Net income (loss)				$ 0				$ 0
Adjustment to basic earnings per share available to TDS common shareholders due to change in accounting estimate (in dollars per share)				$ 0.00				$ 0.00
Adjustment to selling, general and administrative as a result of adoption of new accounting guidance				$ 1,000,000				$ 3,000,000
Adjustment to other, net income as a result of adoption of new accounting pronouncements				1,000,000				3,000,000
Adjustment to income (loss) before income taxes due to adoption of new accounting guidance				$ 0				0
Cumulative impact to retained earnings								$ 0
Franchise rights
Basis of Presentation [Line Items]
Useful life						15 years
Impairment of franchise rights	$ 0
Adjustment to depreciation, amortization and accretion as a result of change in accounting estimate		4,000,000				$ 13,000,000
Net income (loss)		$ (3,000,000)				$ (10,000,000)
Adjustment to basic earnings per share available to TDS common shareholders due to change in accounting estimate (in dollars per share)		$ (0.03)				$ (0.09)
Adjustment to diluted earnings (loss) per share available to TDS common shareholders due to change in accounting estimate (in dollars per share)		$ (0.03)				$ (0.08)
U.S. Cellular
Basis of Presentation [Line Items]
TDS ownership of U.S. Cellular		82.00%				82.00%

[1] As of January 1, 2018, TDS adopted ASU 2014-09 using a modified retrospective approach. Under this method, the new accounting standard is applied only to the most recent period presented. As a result, 2018 amounts include the impacts of ASU 2014-09, but 2017 amounts remain as previously reported, except as specifically stated. See Note 2 — Revenue Recognition for additional information.

[2] ASU 2017-07, regarding net periodic pension cost and net periodic postretirement benefit cost was adopted as of January 1, 2018, and applied retrospectively. All prior year numbers have been recast to conform to this standard.