Information About the Company's Operating Segments - (Adjusted OIBDA) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Adjusted OIBDA	$ 76,066	$ 38,165
Operating Segments
Segment Reporting Information [Line Items]
Adjusted OIBDA	71,085	35,048
Operating Segments | GCI Holdings
Segment Reporting Information [Line Items]
Adjusted OIBDA	86,395	44,471
Operating Segments | Liberty Broadband
Segment Reporting Information [Line Items]
Adjusted OIBDA	(4,981)	(3,117)
Operating Segments | Corporate and other
Segment Reporting Information [Line Items]
Adjusted OIBDA	(10,329)	(6,306)
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Adjusted OIBDA	$ 4,981	$ 3,117