EQUITY PLANS, Stock Option Award Activity (Details) (Cablevision Systems Corporation Employee Stock Plan [Member], USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended				3 Months Ended
	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2013
Stock Options [Member]
Stock Options Outstanding, Weighted Average Exercise Price [Roll Forward]
Balance at beginning of period, weighted average exercise price per share (in dollars per share)					$ 13.05
Granted, weighted average exercise price per share (in dollars per share)					$ 13.98	[1]
Exercised, weighted average exercise price per share (in dollars per share)					$ 13.02
Balance at end of period, weighted average exercise price per share (in dollars per share)	$ 13.16		$ 13.05		$ 13.16
Options exercisable at end of period, weighted average exercise price per share (in dollars per share)	$ 12.39				$ 12.39
Options expected to vest in the future, weighted average exercise price per share (in dollars per share)	$ 14.02				$ 14.02
Stock Options Outstanding, Additional Disclosures [Abstract]
Balance at beginning of period, weighted average remaining contractual term (in years)	7 years 10 months 24 days		7 years 10 months 17 days
Balance at end of period, weighted average remaining contractual term (in years)	7 years 10 months 24 days		7 years 10 months 17 days
Options exercisable at end of period, weighted average remaining contractual term (in years)	6 years 9 months 11 days
Options expected to vest in the future, weighted average remaining contractual term (in years)	9 years 1 month 24 days
Balance at beginning of period, aggregate intrinsic value					$ 29,143	[2]
Balance at end of period, aggregate intrinsic value	31,210	[2]	29,143	[2]	31,210	[2]
Options exercisable at end of period, aggregate intrinsic value	23,092	[2]			23,092	[2]
Options expected to vest in the future, aggregate intrinsic value	$ 7,905	[2]			$ 7,905	[2]
Vesting period (in years)					3 years
Expiration period from date of grant (in years)					10 years
Time Vesting Options [Member]
Stock Options Outstanding [Roll Forward]
Balance at beginning of period (in shares)					2,789,342
Granted (in shares)					2,000,000	[1]
Exercised (in shares)					(16,166)
Forfeited/Expired (in shares)					0
Balance at end of period (in shares)	4,773,176				4,773,176
Options exercisable at end of period (in shares)	2,673,176				2,673,176
Options expected to vest in the future (in shares)	2,100,000				2,100,000
Performance Based Vesting Options [Member]
Stock Options Outstanding [Roll Forward]
Balance at beginning of period (in shares)					12,319,000
Granted (in shares)					0	[1]
Exercised (in shares)					(82,250)
Forfeited/Expired (in shares)					0
Balance at end of period (in shares)	12,236,750				12,236,750
Options exercisable at end of period (in shares)	6,258,600				6,258,600
Options expected to vest in the future (in shares)	5,772,101				5,772,101
AMC Networks Inc. and Madison Square Garden [Member] | Stock Options [Member]
Stock Options Outstanding [Roll Forward]
Balance at end of period (in shares)	658,549				658,549

[1] Options are scheduled to cliff vest at the end of three years and expire 10 years from the date of grant.

[2] The aggregate intrinsic value is calculated as the difference between (i) the exercise price of the underlying award and (ii) the quoted price of CNYG Class A common stock on March 31, 2013 or December 31, 2012, as indicated, and March 31, 2013 in the case of options exercisable and options expected to vest in the future.