Amount of cumulative effect of the change in accounting principle or new accounting pronouncement on retained earnings or other components of equity or net assets in the statement of financial position as of the beginning of the earliest period presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794

Name:	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Basis of Presentation - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
ASC 326
Basis of Presentation [Line Items]
Cumulative effect of change in retained earnings due to adoption of new accounting pronouncement		$ 0
ASU 2018-15
Basis of Presentation [Line Items]
Cumulative effect of change in retained earnings due to adoption of new accounting pronouncement		$ 0
TDS \| U.S. Cellular
Basis of Presentation [Line Items]
Ownership percentage	83.00%