Stock-Based Compensation - Overview (Details) - U S Cellular - Common Shares	Dec. 31, 2018 shares
Long-Term Incentive Plans
Stock-based compensation, overview
Shares reserved (in shares)	13,286,000
Non-Employee Directors' Plan
Stock-based compensation, overview
Shares reserved (in shares)	137,000

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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=109197908&loc=d3e5070-113901

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