RESTRUCTURING AND OTHER EXPENSE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Restructuring Reserve [Roll Forward]
Restructuring Charges	$ 12,923	$ 31,027	$ 149,922
Payments and other	(30,135)	(119,058)	(137,338)
Accrual, beginning balance	35,069	123,100	110,516
Accrual, ending balance	4,008	35,069	123,100
Cumulative restructuring costs				$ 432,609
Payments for Restructuring	30,135	119,058	137,338
Restructuring Reserve	4,008	35,069	123,100	4,008
Transaction costs	5,180	7,521	2,479
Restructuring Reserve, Accrual Adjustment	(13,849)
Restructuring expense relating to right of use operating leases	12,160
CSC Holdings
Restructuring Reserve [Roll Forward]
Transaction costs			2,361
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	6,606	15,580	142,679
Payments and other	(26,384)	(107,600)	(131,324)
Accrual, beginning balance	21,454	113,474	102,119
Accrual, ending balance	1,676	21,454	113,474
Payments for Restructuring	26,384	107,600	131,324
Restructuring Reserve	1,676	21,454	113,474	1,676
Restructuring Reserve, Accrual Adjustment	0
Employee Severance [Member] | 2019 Restructuring
Restructuring Reserve [Roll Forward]
Restructuring Charges	42,715
Payments and other	(4,769)
Accrual, ending balance	37,946
Payments for Restructuring	4,769
Restructuring Reserve	37,946			37,946
Facility Realignment and Other Costs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	6,317	15,447	7,243
Payments and other	(3,751)	(11,458)	(6,014)
Accrual, beginning balance	13,615	9,626	8,397
Accrual, ending balance	2,332	13,615	9,626
Payments for Restructuring	3,751	11,458	6,014
Restructuring Reserve	2,332	$ 13,615	$ 9,626	$ 2,332
Restructuring Reserve, Accrual Adjustment	$ (13,849)