CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Current Assets:
Cash and cash equivalents	$ 611,947	$ 313,991
Restricted cash	29,068	1,149
Accounts receivable, trade (less allowance for doubtful accounts)	295,277	295,149
Prepaid expenses and other current assets	135,579	127,058
Amounts due from affiliates	6,818	25,127
Deferred tax asset	84,925	103,645
Investment securities pledged as collateral	191,338	235,932
Assets distributed to stockholders/sole member in 2011	0	564,231
Total current assets	1,354,952	1,666,282
Property, plant and equipment, net of accumulated depreciation	3,269,232	3,361,590
Other receivables	3,279	4,843
Investment securities pledged as collateral	317,896	235,932
Derivative contracts	18,617	0
Other assets	53,871	44,086
Deferred tax asset	(80,546)	99,287
Amortizable intangible assets, net of accumulated amortization	252,871	292,144
Indefinite-lived cable television franchises	1,240,228	1,240,228
Other indefinite-lived intangible assets	55,895	66,895
Goodwill	442,773	442,067
Deferred financing and other costs, net of accumulated amortization	133,711	140,064
Assets distributed to stockholders/sole member in 2011	0	1,273,674
Total assets	7,143,325	8,867,092
Current Liabilities:
Accounts payable	455,654	435,816
Accrued liabilities:
Interest	146,885	148,734
Employee related costs	246,756	263,134
Other accrued expenses	210,599	222,607
Amounts due to affiliates	32,682	31,517
Deferred revenue	61,599	52,732
Liabilities under derivative contracts	75,223	47,251
Credit facility debt	103,245	157,452
Collateralized indebtedness	148,175	161,358
Capital lease obligations	9,174	1,531
Notes payable	17,614	0
Senior notes	87,822	325,773
Liabilities distributed to stockholders/sole member in 2011	0	336,491
Total current liabilities	1,595,428	2,184,396
Defined benefit plan and other postretirement plan obligations	50,297	78,885
Deferred revenue	10,896	10,946
Liabilities under derivative contracts	3,141	179,327
Other liabilities	170,568	195,033
Deferred tax liability	80,546	(99,287)
Credit facility debt	5,080,949	5,599,058
Collateralized indebtedness	307,763	191,248
Capital lease obligations	33,589	29,706
Notes payable	11,613	0
Senior notes and debentures	5,358,838	5,242,420
Liabilities distributed to stockholders/sole member in 2011	0	1,436,808
Total liabilities	12,703,628	15,147,827
Commitments and contingencies
Redeemable noncontrolling interests	13,761	14,698
Stockholders'/Member Deficiency:
Preferred Stock, $.01 par value, 50,000,000 shares authorized, none issued	0	0
Paid-in capital	1,051,435	6,465
Accumulated deficit	(5,245,483)	(5,494,829)
Total stockholders'/member's deficiency before treasury stock, accumulated other comprehensive loss and noncontrolling interest	(4,190,689)	(5,485,027)
Treasury stock, at cost (61,663,286 and 38,526,921 CNYG Class A common shares)	(1,363,698)	(788,566)
Accumulated other comprehensive loss	(21,468)	(23,325)
Total stockholders'/member deficiency	(5,575,855)	(6,296,918)
Noncontrolling interest	1,791	1,485
Total deficiency	(5,574,064)	(6,295,433)
Total liabilities and stockholders'/member's deficiency	7,143,325	8,867,092
CNYG Class A Common Stock [Member]
Stockholders'/Member Deficiency:
Common stock	2,818	2,796
CNYG Class B Common Stock [Member]
Stockholders'/Member Deficiency:
Common stock	541	541
RMG Class A Common Stock [Member]
Stockholders'/Member Deficiency:
Common stock	0	0
RMG Class B Common Stock [Member]
Stockholders'/Member Deficiency:
Common stock	0	0
CSC Holdings, LLC [Member]
Current Assets:
Cash and cash equivalents	611,054	266,914
Restricted cash	29,068	1,149
Accounts receivable, trade (less allowance for doubtful accounts)	295,277	295,149
Prepaid expenses and other current assets	129,282	122,385
Amounts due from affiliates	503,576	515,698
Deferred tax asset	91,372	155,487
Investment securities pledged as collateral	191,338	235,932
Assets distributed to stockholders/sole member in 2011	0	564,231
Total current assets	1,850,967	2,156,945
Property, plant and equipment, net of accumulated depreciation	3,269,232	3,361,590
Other receivables	3,279	4,843
Investment securities pledged as collateral	317,896	235,932
Derivative contracts	18,617	0
Other assets	53,871	44,086
Deferred tax asset	(600,420)	(368,647)
Amortizable intangible assets, net of accumulated amortization	252,871	292,144
Indefinite-lived cable television franchises	1,240,228	1,240,228
Other indefinite-lived intangible assets	55,895	66,895
Goodwill	442,773	442,067
Deferred financing and other costs, net of accumulated amortization	96,156	98,188
Assets distributed to stockholders/sole member in 2011	0	1,229,374
Total assets	7,601,785	9,172,292
Current Liabilities:
Accounts payable	455,654	435,816
Accrued liabilities:
Interest	102,861	104,709
Employee related costs	240,757	260,672
Other accrued expenses	210,432	206,330
Amounts due to affiliates	30,065	31,200
Deferred revenue	61,599	52,732
Liabilities under derivative contracts	75,223	47,251
Credit facility debt	103,245	157,452
Collateralized indebtedness	148,175	161,358
Capital lease obligations	9,174	1,531
Notes payable	17,614	0
Senior notes	60,997	325,773
Liabilities distributed to stockholders/sole member in 2011	0	336,491
Total current liabilities	1,515,796	2,121,315
Defined benefit plan and other postretirement plan obligations	50,297	78,885
Deferred revenue	10,896	10,946
Liabilities under derivative contracts	3,141	179,327
Other liabilities	168,015	190,034
Deferred tax liability	600,420	368,647
Credit facility debt	5,080,949	5,599,058
Collateralized indebtedness	307,763	191,248
Capital lease obligations	33,589	29,706
Notes payable	11,613	0
Senior notes and debentures	3,218,697	3,076,732
Liabilities distributed to stockholders/sole member in 2011	0	1,460,456
Total liabilities	11,001,176	13,306,354
Commitments and contingencies
Redeemable noncontrolling interests	13,761	14,698
Stockholders'/Member Deficiency:
Accumulated deficit	(3,492,409)	(3,375,506)
Senior notes due from Cablevision	(753,717)	(753,717)
Other member's equity	852,651	2,303
Total stockholders'/member's deficiency before treasury stock, accumulated other comprehensive loss and noncontrolling interest	(3,393,475)	(4,126,920)
Accumulated other comprehensive loss	(21,468)	(23,325)
Total stockholders'/member deficiency	(3,414,943)	(4,150,245)
Noncontrolling interest	1,791	1,485
Total deficiency	(3,413,152)	(4,148,760)
Total liabilities and stockholders'/member's deficiency	$ 7,601,785	$ 9,172,292