SCHEDULE I CONDENSED FINANCIAL INFORMATION OF REGISTRANT, Condensed Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Current Assets:
Cash and cash equivalents	$ 611,947	$ 313,991	$ 215,204	$ 226,549
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 Cablevision	6,818	25,127
Deferred tax asset	84,925	103,645
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
Other assets	53,871	44,086
Deferred tax asset	(80,546)	99,287
Other 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	275,037
Deferred financing and other costs, net of accumulated amortization	133,711	140,064
Total assets	7,143,325	8,867,092
Current Liabilities:
Accounts payable	455,654	435,816
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
Notes payable	17,614	0
Senior notes	87,822	325,773
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
Notes payable	11,613	0
Senior notes and debentures	5,358,838	5,242,420
Commitments and contingencies
Total liabilities	12,703,628	15,147,827
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)
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 deficiency	(5,574,064)	(6,295,433)	(5,155,434)	(5,367,658)
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
Cablevision Systems Corporation [Member]
Current Assets:
Cash and cash equivalents	893	47,077	40,992	27,934
Prepaid expenses and other current assets	6,297	4,673
Amounts due from affiliates, net	4,667	6,412
Deferred tax asset	32,672	0
Total current assets	44,529	58,162
Deferred tax asset	480,755	416,092
Deferred financing and other costs, net of accumulated amortization	37,554	41,876
Investment in affiliate distributed to stockholders/sole member	0	64,606
Total assets	562,838	580,736
Current Liabilities:
Accrued liabilities	50,189	62,764
Amounts due to affiliates	504,042	497,300
Senior notes	26,825	0
Total current liabilities	581,056	560,064
Other liabilities	2,553	4,999
Deferred tax liability	(480,755)	(416,092)
Senior notes and debentures	2,140,141	2,165,688
Senior notes due to Newsday	753,717	753,717
Deficit investment in affiliate, net	2,659,435	3,391,701
Commitments and contingencies
Total liabilities	6,136,902	6,876,169
Stockholders'/Member Deficiency:
Preferred Stock, $.01 par value, 50,000,000 shares authorized, none issued	0	0
Paid-in capital	1,053,226	7,950
Accumulated deficit	(5,245,483)	(5,494,829)
Total stockholders'/member's deficiency before treasury stock, accumulated other comprehensive income and noncontrolling interest	(4,188,898)	(5,483,542)
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 deficiency	(5,574,064)	(6,295,433)
Total liabilities and stockholders'/member's deficiency	562,838	580,736
Cablevision Systems Corporation [Member] | CNYG Class A Common Stock [Member]
Stockholders'/Member Deficiency:
Common Stock	2,818	2,796
Cablevision Systems Corporation [Member] | CNYG Class B Common Stock [Member]
Stockholders'/Member Deficiency:
Common Stock	541	541
Cablevision Systems Corporation [Member] | RMG Class A Common Stock [Member]
Stockholders'/Member Deficiency:
Common Stock		0
Cablevision Systems Corporation [Member] | RMG Class B Common Stock [Member]
Stockholders'/Member Deficiency:
Common Stock		0
CSC Holdings, LLC [Member]
Current Assets:
Cash and cash equivalents	459,574	117,721	76,400	136,190
Restricted cash	27,919	0
Accounts receivable, trade (less allowance for doubtful accounts)	21,348	22,590
Prepaid expenses and other current assets	45,190	36,511
Amounts due from Cablevision	504,042	497,300
Amounts due from other affiliates	146,531	157,875
Deferred tax asset	70,632	83,477
Total current assets	1,275,236	915,474
Property, plant and equipment, net of accumulated depreciation	599,085	581,435
Investment in affiliates, net	2,080,450	2,417,690
Other receivables	3,279	4,126
Other assets	31,446	26,742
Deferred tax asset	(52,629)	48,761
Other amortizable intangible assets, net of accumulated amortization	1,792	1,110
Indefinite-lived cable television franchises	95	95
Other indefinite-lived intangible assets	250	250
Goodwill	6,168	6,168
Deferred financing and other costs, net of accumulated amortization	63,253	57,164
Total assets	4,061,054	4,059,015
Current Liabilities:
Accounts payable	114,840	115,525
Accrued liabilities	248,927	238,947
Amounts due to affiliates	20,176	5,635
Deferred revenue	5,083	4,765
Liabilities under derivative contracts	55,383	0
Credit facility debt	95,595	149,802
Notes payable	16,174	0
Senior notes	60,997	325,773
Total current liabilities	617,175	840,447
Defined benefit plan and other postretirement plan obligations	50,297	78,885
Deferred revenue	277	465
Liabilities under derivative contracts	0	167,278
Other liabilities	86,373	91,316
Deferred tax liability	52,629	(48,761)
Credit facility debt	3,687,865	4,199,310
Notes payable	10,893	0
Senior notes and debentures	2,968,697	2,826,732
Deficit investment in affiliate, net	0	3,342
Commitments and contingencies
Total liabilities	7,474,206	8,207,775
Stockholders'/Member Deficiency:
Accumulated deficit	(3,492,409)	(3,375,506)
Senior notes due from Cablevision	(753,717)	(753,717)
Other member's equity (14,432,750 membership units issued and outstanding)	854,442	3,788
Total stockholders'/member's deficiency before treasury stock, accumulated other comprehensive income and noncontrolling interest	(3,391,684)	(4,125,435)
Accumulated other comprehensive loss	(21,468)	(23,325)
Total deficiency	(3,413,152)	(4,148,760)
Total liabilities and stockholders'/member's deficiency	$ 4,061,054	$ 4,059,015