DEBT - Credit Facilities Outstanding (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt	$ 25,057,488	$ 25,057,488	$ 25,074,961
Principal Amount	$ 25,096,412	25,096,412	25,126,605
2027 Revolving Credit Commitments
Debt Instrument [Line Items]
Line of credit facility, periodic payment amount		95
2025 Revolving Credit Commitments
Debt Instrument [Line Items]
Line of credit facility, periodic payment amount		$ 20
CSC Holdings Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Stated interest rate	6.747%	6.747%
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,475,000	$ 2,475,000
Credit facility, Carrying Value	1,697,559	1,697,559	821,632
Letters of credit outstanding	163,738	163,738
Line of credit facility, remaining borrowing capacity	611,262	611,262
Proceeds from long-term debt		2,025,000
Principal Amount	1,700,000	1,700,000	825,000
CSC Holdings Term Loan B | Secured Debt [Member]
Debt Instrument [Line Items]
Credit facility, Carrying Value	0	0	1,518,530
Principal Amount	0	0	1,520,483
Incremental Term Loan B-3 | Secured Debt [Member]
Debt Instrument [Line Items]
Credit facility, Carrying Value	0	0	520,988
Principal Amount	$ 0	$ 0	521,744
Incremental Term Loan B-5 | Secured Debt [Member]
Debt Instrument [Line Items]
Stated interest rate	7.174%	7.174%
Credit facility, Carrying Value	$ 2,849,460	$ 2,849,460	2,876,131
Line of credit facility, periodic payment amount	7,500
Principal Amount	$ 2,857,500	$ 2,857,500	2,887,500
Incremental Term Loan B-5 | Secured Debt [Member] | Alternate base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		1.50%
Incremental Term Loan B-6 | Secured Debt [Member]
Debt Instrument [Line Items]
Stated interest rate	8.897%	8.897%
Credit facility, Carrying Value	$ 1,936,863	$ 1,936,863	1,948,503
Line of credit facility, periodic payment amount	5,005
Principal Amount	1,966,908	1,966,908	1,986,928
Cablevision Lightpath Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	115	115		$ 100,000
Credit facility, Carrying Value	0	0	0
Proceeds from long-term debt		40
Line of Credit Facility, Increase (Decrease), Net		15
Principal Amount	$ 0	$ 0	0
Cablevision Lightpath Term B Loan
Debt Instrument [Line Items]
Incurrence Test	4.75	4.75
Cablevision Lightpath Term B Loan | Secured Debt [Member]
Debt Instrument [Line Items]
Stated interest rate	7.762%	7.762%
Credit facility, Carrying Value	$ 673,107	$ 673,107	571,898
Line of credit facility, periodic payment amount	1,760
Principal Amount	$ 676,000	676,000	$ 582,000	$ 600,000
Debt Instrument, Increase (Decrease), Net		$ 100,000
Net price of debt issued	99.27%	99.27%
Cablevision Lightpath Term B Loan | Secured Debt [Member] | Alternate base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%
Cablevision Lightpath Term B Loan | Secured Debt [Member] | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate		3.25%