INCOME TAXES - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
NOLs and tax credit carry forwards	$ 309,924	$ 571,413
Compensation and benefit plans	25,227	42,484
Partnership investments	49,956	60,413
Restructuring liability	11,280	9,364
Other liabilities	42,339	38,473
Liabilities under derivative contracts	43,175	20,846
Interest deferred for tax purposes	333,856	166,668
Operating lease Liability	82,393	0
Other	12,428	11,531
Deferred tax asset	910,578	921,192
Valuation allowance	(29,479)	(25,400)
Net deferred tax asset, noncurrent	881,099	895,792
Fixed assets and intangibles	(5,384,320)	(5,496,103)
Operating lease Asset	(75,019)	0
Investments	(116,702)	(71,167)
Prepaid expenses	(10,978)	(7,543)
Fair value adjustments related to debt and deferred financing costs	(56,675)	(40,083)
Other	0	(4,833)
Deferred tax liability, noncurrent	(5,643,694)	(5,619,729)
Total net deferred tax liability	(4,762,595)	(4,723,937)
CSC Holdings
NOLs and tax credit carry forwards	74,300	16,465
Compensation and benefit plans	25,227	45,138
Partnership investments	49,956	60,413
Restructuring liability	11,280	9,364
Other liabilities	42,339	36,833
Liabilities under derivative contracts	43,175	20,847
Interest deferred for tax purposes	333,856	34,843
Operating lease Liability	82,393	0
Other	12,428	9,867
Deferred tax asset	674,954	233,770
Valuation allowance	(11,859)	(8,225)
Net deferred tax asset, noncurrent	663,095	225,545
Fixed assets and intangibles	(5,384,320)	(5,473,397)
Operating lease Asset	(75,019)	0
Investments	(116,702)	(71,168)
Prepaid expenses	(10,978)	(7,543)
Fair value adjustments related to debt and deferred financing costs	(56,675)	(18,111)
Other	0	(5,273)
Deferred tax liability, noncurrent	(5,643,694)	(5,575,492)
Total net deferred tax liability	$ (4,980,599)	$ (5,349,947)