Information About the Company's Operating Segments - (Adjusted OIBDA) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Adjusted OIBDA	$ 61,399	$ 74,115	$ 100,746	$ 88,203
Operating Segments
Segment Reporting Information [Line Items]
Adjusted OIBDA	57,225	71,339	93,455	89,987
Operating Segments | GCI Holdings
Segment Reporting Information [Line Items]
Adjusted OIBDA	66,121	78,915	110,592	98,663
Operating Segments | Liberty Broadband
Segment Reporting Information [Line Items]
Adjusted OIBDA	(4,174)	(2,776)	(7,291)	1,784
Operating Segments | Corporate and other
Segment Reporting Information [Line Items]
Adjusted OIBDA	(4,722)	(4,800)	(9,846)	(10,460)
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Adjusted OIBDA	$ 4,174	$ 2,776	$ 7,291	$ (1,784)