CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 244,140	$ 332,833
Accounts receivable, trade (less allowance for doubtful accounts)	248,518	315,113
Prepaid expenses and other current assets	145,176	133,331
Amounts due from affiliates	11,991	5,339
Deferred tax asset	134,732	139,716
Investment securities pledged as collateral	336,358	401,417
Assets held for sale	50,893	49,803
Total current assets	1,171,808	1,377,552
Property, plant and equipment, net of accumulated depreciation	2,931,605	2,959,654
Other receivables	4,066	4,268
Investment securities pledged as collateral	565,916	401,417
Derivative contracts	4,002	3,143
Other assets	41,203	41,169
Amortizable intangible assets, net of accumulated amortization	70,378	71,260
Indefinite-lived cable television franchises	731,848	731,848
Other indefinite-lived intangible assets	32,550	32,550
Goodwill	264,690	275,037
Deferred financing costs, net of accumulated amortization	97,414	101,789
Assets held for sale	1,227,673	1,250,602
Total assets	7,143,153	7,250,289
Current Liabilities:
Accounts payable	402,709	459,045
Accrued liabilities	468,638	505,134
Amounts due to affiliates	32,570	36,397
Deferred tax liability	(134,732)	(139,716)
Deferred revenue	58,690	58,775
Liabilities under derivative contracts	152,977	134,524
Credit facility debt	37,625	165,334
Collateralized indebtedness	182,623	248,760
Capital lease obligations	10,724	11,009
Notes payable	9,964	10,676
Liabilities held for sale	81,765	67,359
Total current liabilities	1,438,285	1,697,013
Deferred revenue	6,468	6,946
Liabilities under derivative contracts	35,438	13,739
Other liabilities	319,864	300,399
Deferred tax liability	184,359	204,422
Credit facility debt	3,844,596	3,748,667
Collateralized indebtedness	417,752	307,392
Capital lease obligations	52,441	45,560
Notes payable	1,766	1,909
Senior notes and debentures	5,490,456	5,488,219
Liabilities held for sale	1,027,719	1,062,030
Total liabilities	12,819,144	12,876,296
Commitments and contingencies
Redeemable noncontrolling interests	12,211	11,999
Stockholders'/Member's Deficiency:
Preferred Stock, $.01 par value, 50,000,000 shares authorized, none issued	0	0
Paid-in capital	949,451	972,274
Accumulated deficit	(5,028,101)	(5,011,960)
Total stockholders'/member's deficiency before treasury stock, accumulated other comprehensive loss and noncontrolling interest	(4,075,198)	(4,036,267)
Treasury stock, at cost (78,024,481 and 77,189,014 CNYG Class A common shares)	(1,583,518)	(1,572,134)
Accumulated other comprehensive loss	(30,553)	(30,763)
Total stockholders'/member's deficiency	(5,689,269)	(5,639,164)
Noncontrolling interests	1,067	1,158
Total deficiency	(5,688,202)	(5,638,006)
Total liabilities and stockholders'/member's deficiency	7,143,153	7,250,289
CNYG Class A Common Stock [Member]
Stockholders'/Member's Deficiency:
Common stock	2,911	2,878
CNYG Class B Common Stock [Member]
Stockholders'/Member's Deficiency:
Common stock	541	541
RMG Class A Common Stock [Member]
Stockholders'/Member's Deficiency:
Common stock	0	0
RMG Class B Common Stock [Member]
Stockholders'/Member's Deficiency:
Common stock	0	0
CSC Holdings, LLC [Member]
Current Assets:
Cash and cash equivalents	159,833	256,967
Accounts receivable, trade (less allowance for doubtful accounts)	248,518	315,113
Prepaid expenses and other current assets	140,642	121,130
Amounts due from affiliates	505,400	487,352
Deferred tax asset	21,270	(4,367)
Investment securities pledged as collateral	336,358	401,417
Assets held for sale	50,893	49,803
Total current assets	1,462,914	1,631,782
Property, plant and equipment, net of accumulated depreciation	2,931,605	2,959,654
Other receivables	2,288	2,490
Investment securities pledged as collateral	565,916	401,417
Derivative contracts	4,002	3,143
Other assets	41,203	41,169
Amortizable intangible assets, net of accumulated amortization	70,378	71,260
Indefinite-lived cable television franchises	731,848	731,848
Other indefinite-lived intangible assets	32,550	32,550
Goodwill	264,690	275,037
Deferred financing costs, net of accumulated amortization	50,156	53,024
Assets held for sale	1,227,673	1,250,602
Total assets	7,385,223	7,453,976
Current Liabilities:
Accounts payable	402,709	459,045
Accrued liabilities	377,754	446,969
Amounts due to affiliates	32,570	33,311
Deferred tax liability	(21,270)	4,367
Deferred revenue	58,690	58,775
Liabilities under derivative contracts	152,977	134,524
Credit facility debt	37,625	165,334
Collateralized indebtedness	182,623	248,760
Capital lease obligations	10,724	11,009
Notes payable	9,964	10,676
Liabilities held for sale	81,765	67,359
Total current liabilities	1,347,401	1,640,129
Deferred revenue	6,468	6,946
Liabilities under derivative contracts	35,438	13,739
Other liabilities	317,360	297,794
Deferred tax liability	607,050	571,743
Credit facility debt	3,844,596	3,748,667
Collateralized indebtedness	417,752	307,392
Capital lease obligations	52,441	45,560
Notes payable	1,766	1,909
Senior notes and debentures	2,598,555	2,596,683
Liabilities held for sale	1,027,719	1,062,030
Total liabilities	10,256,546	10,292,592
Commitments and contingencies
Redeemable noncontrolling interests	12,211	11,999
Stockholders'/Member's Deficiency:
Accumulated deficit	(3,081,201)	(3,106,148)
Senior notes due from Cablevision	(753,717)	(753,717)
Other member's equity	980,870	1,038,855
Total stockholders'/member's deficiency before treasury stock, accumulated other comprehensive loss and noncontrolling interest	(2,854,048)	(2,821,010)
Accumulated other comprehensive loss	(30,553)	(30,763)
Total stockholders'/member's deficiency	(2,884,601)	(2,851,773)
Noncontrolling interests	1,067	1,158
Total deficiency	(2,883,534)	(2,850,615)
Total liabilities and stockholders'/member's deficiency	$ 7,385,223	$ 7,453,976