EQUITY AND LONG-TERM INCENTIVE PLANS, Valuation Assumptions (Details) (Cablevision Systems Corporation Employee Stock Plan, Stock Options, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cablevision Systems Corporation Employee Stock Plan | Stock Options
Assumptions Used to Calculate the Fair Value of Stock Option Awards Granted [Abstract]
Risk-free interest rate (in hundredths)	2.12%	1.25%	1.14%
Expected life (in years)	6 years 6 months	6 years 6 months	5 years 9 months
Dividend yield (in hundredths)	3.79%	3.86%	3.52%
Volatility (in hundredths)	42.80%	42.31%	43.20%
Grant date fair value (in dollars per share)	$ 5.27	$ 3.96	$ 4.06