Liberty Broadband Corporation Quarterly report pursuant to Section 13 or 15(d)

Information About the Company's Operating Segments (Other Information) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 9,344,097	$ 6,172,213
Investments accounted for using the equity method	121,880	$ 114,655
Capital expenditures	40,303
Operating Segments
Segment Reporting Information [Line Items]
Total assets	21,347,025
Investments accounted for using the equity method	12,013,517
Capital expenditures	40,327
Operating Segments \| GCI Holdings
Segment Reporting Information [Line Items]
Total assets	3,530,980
Investments accounted for using the equity method	0
Capital expenditures	38,788
Operating Segments \| Liberty Broadband
Segment Reporting Information [Line Items]
Total assets	12,002,928
Investments accounted for using the equity method	11,891,637
Capital expenditures	24
Operating Segments \| Corporate and other
Segment Reporting Information [Line Items]
Total assets	5,813,117
Investments accounted for using the equity method	121,880
Capital expenditures	1,515
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Total assets	(12,002,928)
Investments accounted for using the equity method	(11,891,637)
Capital expenditures	$ (24)