FAIR VALUE MEASUREMENT (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Assets [Abstract]
Money market funds	$ 556,853		$ 259,463
Restricted money market funds	27,920
Investment securities	113		101
Investment securities pledged as collateral	509,234		471,864
Prepaid forward contracts	18,617
Liabilities under derivative contracts [Abstract]
Prepaid forward contracts	22,981		59,300
Interest rate swap contracts	55,383		167,278
Carrying Amount [Member]
Debt instruments [Abstract]
Senior notes and debentures	2,166,966		2,165,688
Total debt instruments	11,116,019		11,677,309
Estimated Fair Value [Member]
Debt instruments [Abstract]
Senior notes and debentures	2,355,160		2,328,644
Total debt instruments	11,657,886		12,263,408
CSC Holdings, LLC [Member] | Carrying Amount [Member]
CSC Holdings notes receivable [Abstract]
Cablevision senior notes held by Newsday Holdings LLC	753,717	[1]	753,717	[1]
Debt instruments [Abstract]
Credit facility debt	5,184,194	[2]	5,756,510	[2]
Collateralized indebtedness	455,938		352,606
Senior notes and debentures	3,279,694		3,402,505
Notes payable	29,227
Total debt instruments	8,949,053		9,511,621
CSC Holdings, LLC [Member] | Estimated Fair Value [Member]
CSC Holdings notes receivable [Abstract]
Cablevision senior notes held by Newsday Holdings LLC	802,268	[1]	795,508	[1]
Debt instruments [Abstract]
Credit facility debt	5,198,987	[2]	5,802,917	[2]
Collateralized indebtedness	446,660		349,853
Senior notes and debentures	3,627,852		3,781,994
Notes payable	29,227
Total debt instruments	9,302,726		9,934,764
Level I [Member]
Assets [Abstract]
Money market funds	556,853		259,463
Restricted money market funds	27,920
Investment securities	113		101
Investment securities pledged as collateral	509,234		471,864
Prepaid forward contracts	0
Liabilities under derivative contracts [Abstract]
Prepaid forward contracts	0		0
Interest rate swap contracts	0		0
Level II [Member]
Assets [Abstract]
Money market funds	0		0
Restricted money market funds	0
Investment securities	0		0
Investment securities pledged as collateral	0		0
Prepaid forward contracts	18,617
Liabilities under derivative contracts [Abstract]
Prepaid forward contracts	22,981		59,300
Interest rate swap contracts	55,383		167,278
Level III [Member]
Assets [Abstract]
Money market funds	0		0
Restricted money market funds	0
Investment securities	0		0
Investment securities pledged as collateral	0		0
Prepaid forward contracts	0
Liabilities under derivative contracts [Abstract]
Prepaid forward contracts	0		0
Interest rate swap contracts	$ 0		$ 0

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

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