Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Change Due to Net Income Attributable to Parent and Effects of Changes, Net [Abstract]
Net income attributable to TDS shareholders	$ 135	$ 153	$ 43
Transfer (to) from the noncontrolling interests
Change in TDS' Capital in excess of par value from U.S. Cellular's issuance of U.S. Cellular shares	(30)	(12)	(16)
Change in TDS' Capital in excess of par value from U.S. Cellular's repurchase of U.S. Cellular shares	0	0	1
Net transfers (to) from noncontrolling interests	(30)	(12)	(15)
Change from net income attributable to TDS shareholders and transfers (to) from noncontrolling interests	105	$ 141	$ 28
Redeemable noncontrolling interest
Settlement value of mandatorily redeemable noncontrolling interests	17
Carrying value of mandatorily redeemable noncontrolling interests	$ 4

This element represents the total net income attributable to the parent for the period and the effect of net changes during the period impacting the parent's ownership interest in a subsidiary as it relates to the total (consolidated) equity attributable to the parent. The changes to the parent's ownership interest in a subsidiary represented by this element did not result in a deconsolidation of the subsidiary from the consolidated financial statements.

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Represents a sale (new stock issuance) by a subsidiary to noncontrolling interests (third parties, parties directly or indirectly unrelated to parent) during the period. The capital transaction by subsidiary does not result in a loss of control by the parent, but does effect a change in total (consolidated) equity attributable to the parent.

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The increase (decrease) during the period impacting the parent's ownership interest in a subsidiary as it relates to the total (consolidated) equity attributable to the parent. The changes to the parent's ownership interest in a subsidiary represented by this element did not arise in a deconsolidation of the subsidiary from the consolidated financial statements.

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Represents the repurchase of equity (treasury stock) by a subsidiary during the period, thereby effecting a change in total (consolidated) equity attributable to the parent; but not deconsolidation by the parent.

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- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

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The aggregate fair value as of the reporting date of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

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