CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current Assets:
Accounts receivable, trade allowance for doubtful accounts	$ 11,224	$ 12,112
Property, plant and equipment, accumulated depreciation	9,543,360	9,454,315
Amortizable intangible assets, accumulated amortization	61,438	60,018
Deferred financing costs, accumulated amortization	63,106	58,651
Stockholders' Deficiency:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
CNYG Class A Common Stock
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	800,000,000	800,000,000
Common stock, shares issued (in shares)	302,828,479	300,342,849
Common stock, shares outstanding (in shares)	221,567,532	220,219,935
Treasury stock (in shares)	81,260,947	80,122,914
CNYG Class B Common Stock
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	320,000,000	320,000,000
Common stock, shares issued (in shares)	54,137,673	54,137,673
Common stock, shares outstanding (in shares)	54,137,673	54,137,673
RMG Class A Common Stock
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Common stock, shares issued (in shares)	0	0
RMG Class B Common Stock
Stockholders' Deficiency:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	160,000,000	160,000,000
Common stock, shares issued (in shares)	0	0
CSC Holdings, LLC
Current Assets:
Accounts receivable, trade allowance for doubtful accounts	11,224	12,112
Property, plant and equipment, accumulated depreciation	9,543,360	9,454,315
Amortizable intangible assets, accumulated amortization	61,438	60,018
Deferred financing costs, accumulated amortization	$ 35,718	$ 32,983
Stockholders' Deficiency:
Other member's equity, membership units issued (in shares)	17,631,479	17,631,479
Other member's equity, membership units outstanding (in shares)	17,631,479	17,631,479