FAIR VALUE MEASUREMENT, Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Carrying Amount
Debt instruments:
Total debt instruments		$ 9,579,302	$ 9,646,610
Estimated Fair Value
Debt instruments:
Total debt instruments		9,210,627	10,184,722
CSC Holdings, LLC | Carrying Amount
Debt instruments:
Total debt instruments		6,784,222	6,852,869
CSC Holdings, LLC | Carrying Amount | Level II
CSC Holdings notes receivable:
Cablevision senior notes held by Newsday Holdings LLC	[1]	611,455	611,455
Debt instruments:
Credit facility debt	[2]	2,536,684	2,780,649
Collateralized indebtedness		1,164,577	986,183
Senior notes and debentures		3,064,327	3,062,126
Notes payable		18,634	23,911
CSC Holdings, LLC | Estimated Fair Value
Debt instruments:
Total debt instruments		6,578,001	7,136,335
CSC Holdings, LLC | Estimated Fair Value | Level II
CSC Holdings notes receivable:
Cablevision senior notes held by Newsday Holdings LLC	[1]	582,837	680,587
Debt instruments:
Credit facility debt	[2]	2,540,606	2,785,975
Collateralized indebtedness		1,143,388	957,803
Senior notes and debentures		2,875,440	3,368,875
Notes payable		18,567	23,682
Cablevision Systems Corporation | Carrying Amount | Level II
Debt instruments:
Senior notes and debentures		2,795,080	2,793,741
Cablevision Systems Corporation | Estimated Fair Value | Level II
Debt instruments:
Senior notes and debentures		$ 2,632,626	$ 3,048,387

[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.