Noncontrolling Interests (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
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	$ 69	$ 59
Transfers (to) from noncontrolling interests
Change in TDS' Capital in excess of par value from U.S. Cellular's issuance of U.S. Cellular shares	(1)	(2)
Change in TDS' Capital in excess of par value from U.S. Cellular's repurchases of U.S. Cellular shares	13	0
Net transfers (to) from noncontrolling interests	12	(2)
Changes from net income attributable to TDS shareholders and transfers (to) from noncontrolling interests	$ 81	$ 57

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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- Definition

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

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