Acquisition (Pro Forma Revenue and Net Earnings) (Details) - HoldCo - GCI Liberty Inc - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Revenue	$ 899,210	$ 918,726
Net earnings (loss)	(913,936)	749,959
Net earnings (loss) attributable to GCI, LLC member	$ (913,469)	$ 750,464

Business Acquisition, Pro Forma Net Income (Loss) Attributable To Common Shareholders

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(3)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 805
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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