Liberty Broadband Corporation Annual report pursuant to Section 13 and 15(d)

Information About the Company's Operating Segments (Performance Measures) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenue	$ 232,387	$ 227,044	$ 217,566	$ 217,736	$ 234,922	$ 210,146	$ 233,490	$ 61,204	$ 894,733	$ 739,762	$ 23,817
Adjusted OIBDA									235,013	193,101	(25,762)
Operating Segments
Segment Reporting Information [Line Items]
Revenue									909,592	762,018	36,909
Adjusted OIBDA									218,122	189,573	(42,178)
Operating Segments \| GCI Holdings
Segment Reporting Information [Line Items]
Revenue									869,662	715,842	0
Adjusted OIBDA									256,878	217,832	0
Operating Segments \| Liberty Broadband
Segment Reporting Information [Line Items]
Revenue									14,859	22,256	13,092
Adjusted OIBDA									(16,891)	(3,528)	(16,416)
Operating Segments \| Corporate and other
Segment Reporting Information [Line Items]
Revenue											23,817
Adjusted OIBDA									(21,865)	(24,731)	(25,762)
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Revenue									(14,859)	(22,256)	(13,092)
Adjusted OIBDA									$ 16,891	$ 3,528	$ 16,416