DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended																						12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Comcast Corporation Shares [Member]	Dec. 31, 2010 Comcast Corporation Shares [Member]	Dec. 31, 2011 Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2010 Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2009 Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2011 Interest Rate Swap Contracts [Member] Loss on Interest Rate Swap Contracts, Net [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2010 Interest Rate Swap Contracts [Member] Loss on Interest Rate Swap Contracts, Net [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2009 Interest Rate Swap Contracts [Member] Loss on Interest Rate Swap Contracts, Net [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2011 Prepaid Forward Contracts [Member] Gain (Loss) on Equity Derivative Contracts, Net [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2010 Prepaid Forward Contracts [Member] Gain (Loss) on Equity Derivative Contracts, Net [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2009 Prepaid Forward Contracts [Member] Gain (Loss) on Equity Derivative Contracts, Net [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2011 Interest Rate Swap Contracts [Member] Current Derivative Contracts [Member]	Dec. 31, 2010 Interest Rate Swap Contracts [Member] Current Derivative Contracts [Member]	Dec. 31, 2011 Interest Rate Swap Contracts [Member] Long Term Derivative Contracts [Member]	Dec. 31, 2010 Interest Rate Swap Contracts [Member] Long Term Derivative Contracts [Member]	Dec. 31, 2011 Prepaid Forward Contracts [Member] Current Derivative Contracts [Member]	Dec. 31, 2010 Prepaid Forward Contracts [Member] Current Derivative Contracts [Member]	Dec. 31, 2011 Prepaid Forward Contracts [Member] Long Term Derivative Contracts [Member]	Dec. 31, 2010 Prepaid Forward Contracts [Member] Long Term Derivative Contracts [Member]	Dec. 31, 2011 CSC Holdings, LLC [Member]	Dec. 31, 2010 CSC Holdings, LLC [Member]	Dec. 31, 2009 CSC Holdings, LLC [Member]	Dec. 31, 2011 CSC Holdings, LLC [Member] Interest Rate Swap Contracts [Member]		Mar. 31, 2010 CSC Holdings, LLC [Member] Interest Rate Swap Contracts [Member]
Derivative Contracts and Collateralized Indebtedness [Abstract]
Percentage of outstanding debt (excluding capital leases and collateralized indebtedness) with paid interest rate effectively fixed (in hundredths)	81.00%
Percentage of outstanding debt with paid interest rate effectively fixed with fixed rate obligations (in hundredths)	56.00%
Percentage of outstanding debt with interest rate effectively fixed through utilization of interest rate swap contracts (in hundredths)	25.00%
Certain terms of interest rate swap contracts [Abstract]
Maturity date																										Jun. 30, 2012
Notional amount																										$ 2,600,000		$ 1,100,000
Weighted average fixed rate paid by the company (in hundredths)																										4.86%
Weighted average effective floating rate received by the company at December 31 (in hundredths)																										0.54%	[1]
Guarantee exposure	1,400
Fair Value, Derivatives [Abstract]
Asset derivatives, fair value	18,617	0													0	0	18,617	0	0	0	0	0
Liability derivatives, fair value	78,364	226,578													55,383	0	0	167,278	19,840	47,251	3,141	12,049
Derivative instruments. gain (loss) recognized in income [Abstract]
Amount of gain (loss) recognized						(6,519)	(157,057)	(75,000)	(7,973)	(85,013)	(75,631)	1,454	(72,044)	631
Gain (loss) on investment securities pledged as collateral	37,370	109,751	(430)
Principal collateralized indebtedness obligations relating to shares of Comcast common stock that mature during the next 12 months	148,175
Settlement of collateralized indebtedness [Abstract]
Number of shares (in shares)				13,407,684	8,069,934
Collateralized indebtedness settled				(204,431)	(171,400)
Derivative contracts settled				(53,482)	23,226
Repayment of collateralized indebtedness	(257,913)	(148,174)	(161,358)	(257,913)	(148,174)																		(257,913)	(148,174)	(161,358)
Proceeds from new monetization contracts	307,763	148,174	161,358	307,763	148,174																		307,763	148,174	161,358
Net cash receipt				$ 49,850	$ 0

[1] Represents the weighted average effective floating rate received by the Company under its interest rate swap contracts at December 31, 2011 and does not represent the rates to be received by the Company on future payments.