SEGMENT INFORMATION - Capital Expenditures by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information, Capital Expenditures [Abstract]
Capital expenditures	$ 240,682	$ 206,163	$ 498,297	$ 463,590
Cablevision
Segment Reporting Information, Capital Expenditures [Abstract]
Capital expenditures	170,356	141,166	337,157	325,565
Cequel Corp. [Member]
Segment Reporting Information, Capital Expenditures [Abstract]
Capital expenditures	$ 70,326	$ 64,997	$ 161,140	$ 138,025