FAIR VALUE MEASUREMENT, Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Carrying Amount
Debt instruments:
Total debt instruments	$ 9,676,471		$ 9,646,610
Estimated Fair Value
Debt instruments:
Total debt instruments	10,281,929		10,184,722
CSC Holdings, LLC | Carrying Amount
Debt instruments:
Total debt instruments	6,882,296		6,852,869
CSC Holdings, LLC | Carrying Amount | Level II
CSC Holdings notes receivable:
Cablevision senior notes held by Newsday Holdings LLC	611,455	[1]	611,455	[1]
Debt instruments:
Credit facility debt	2,765,430	[2]	2,780,649	[2]
Collateralized indebtedness	1,033,040		986,183
Senior notes and debentures	3,062,844		3,062,126
Notes payable	20,982		23,911
CSC Holdings, LLC | Estimated Fair Value
Debt instruments:
Total debt instruments	7,190,826		7,136,335
CSC Holdings, LLC | Estimated Fair Value | Level II
CSC Holdings notes receivable:
Cablevision senior notes held by Newsday Holdings LLC	684,705	[1]	680,587	[1]
Debt instruments:
Credit facility debt	2,770,513	[2]	2,785,975	[2]
Collateralized indebtedness	1,014,426		957,803
Senior notes and debentures	3,385,095		3,368,875
Notes payable	20,792		23,682
Cablevision Systems Corporation | Carrying Amount | Level II
Debt instruments:
Senior notes and debentures	2,794,175		2,793,741
Cablevision Systems Corporation | Estimated Fair Value | Level II
Debt instruments:
Senior notes and debentures	$ 3,091,103		$ 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.