Stock-Based Compensation - Overview (Details) - U S Cellular - Common Shares	Dec. 31, 2019 shares
Long-Term Incentive Plans
Stock-based compensation, overview
Shares reserved (in shares)	12,867,000
Non-Employee Directors' Plan
Stock-based compensation, overview
Shares reserved (in shares)	123,000

Number of shares authorized for issuance under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant