FAIR VALUE MEASUREMENT, Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Carrying Amount
Debt instruments:
Total debt instruments	$ 9,646,610		$ 9,727,944
Carrying Amount | Level II
Debt instruments:
Senior notes and debentures	2,793,741		2,829,112
Estimated Fair Value
Debt instruments:
Total debt instruments	10,184,722		10,301,457
Estimated Fair Value | Level II
Debt instruments:
Senior notes and debentures	3,048,387		3,101,373
CSC Holdings, LLC | Carrying Amount
Debt instruments:
Total debt instruments	6,852,869		6,898,832
CSC Holdings, LLC | Carrying Amount | Level II
CSC Holdings notes receivable:
Cablevision senior notes held by Newsday Holdings	611,455	[1]	611,455	[1]
Debt instruments:
Credit facility debt	2,780,649	[2]	3,766,145	[2]
Collateralized indebtedness	986,183		817,950
Senior notes and debentures	3,062,126		2,309,403
Notes payable	23,911		5,334
CSC Holdings, LLC | Estimated Fair Value
Debt instruments:
Total debt instruments	7,136,335		7,200,084
CSC Holdings, LLC | Estimated Fair Value | Level II
CSC Holdings notes receivable:
Cablevision senior notes held by Newsday Holdings	680,587	[1]	682,887	[1]
Debt instruments:
Credit facility debt	2,785,975	[2]	3,776,760	[2]
Collateralized indebtedness	957,803		809,105
Senior notes and debentures	3,368,875		2,608,885
Notes payable	$ 23,682		$ 5,334

[1] These notes are eliminated at the consolidated Cablevision level.

[2] The principal amount of the Company's credit facility debt, which bears interest at variable rates, approximates its fair value.