CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIENCY (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		$ (5,283,544)		$ (5,638,006)	$ (5,283,544)	$ (5,638,006)	$ (5,574,064)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member	55,975	89,763	51,842	(16,141)	311,439	465,661	233,523
Net income attributable to noncontrolling interests					1,007	1,052	1,638
Pension and postretirement plan liability adjustments, net of income taxes					459	(11,931)	(9,295)
Proceeds from exercise of options and issuance of restricted shares					55,330	18,196	18,722
Recognition of equity-based stock compensation arrangements					44,335	52,777	62,039
Treasury stock acquired from forfeiture and acquisition of restricted shares					(6,608)	(12,262)	(19,831)
Treasury stock acquired through share repurchase program							(188,600)
Tax withholding associated with shares issued for equity-based compensation						(644)
Excess tax benefit on share-based awards					336	1,280
Dividends on CNYG Class A and CNYG Class B common stock					(162,806)	(160,083)	(161,004)
Adjustments to noncontrolling interests					(638)	416	(1,374)
Balance	(5,040,690)		(5,283,544)		(5,040,690)	(5,283,544)	(5,638,006)
AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							240
Common Stock | CNYG Class A Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		2,925		2,878	2,925	2,878	2,818
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Proceeds from exercise of options and issuance of restricted shares					78	47	60
Recognition of equity-based stock compensation arrangements					0	0	0
Treasury stock acquired from forfeiture and acquisition of restricted shares					0	0	0
Treasury stock acquired through share repurchase program							0
Tax withholding associated with shares issued for equity-based compensation						0
Excess tax benefit on share-based awards					0	0
Dividends on CNYG Class A and CNYG Class B common stock					0	0	0
Adjustments to noncontrolling interests					0	0	0
Balance	3,003		2,925		3,003	2,925	2,878
Common Stock | CNYG Class A Common Stock | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
Common Stock | CNYG Class B Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		541		541	541	541	541
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Proceeds from exercise of options and issuance of restricted shares					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Treasury stock acquired from forfeiture and acquisition of restricted shares					0	0	0
Treasury stock acquired through share repurchase program							0
Tax withholding associated with shares issued for equity-based compensation						0
Excess tax benefit on share-based awards					0	0
Dividends on CNYG Class A and CNYG Class B common stock					0	0	0
Adjustments to noncontrolling interests					0	0	0
Balance	541		541		541	541	541
Common Stock | CNYG Class B Common Stock | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		885,601		972,274	885,601	972,274	1,051,435
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Proceeds from exercise of options and issuance of restricted shares					55,252	18,149	18,662
Recognition of equity-based stock compensation arrangements					44,335	52,777	62,039
Treasury stock acquired from forfeiture and acquisition of restricted shares					9	8	5
Treasury stock acquired through share repurchase program							0
Tax withholding associated with shares issued for equity-based compensation						(644)
Excess tax benefit on share-based awards					336	1,280
Dividends on CNYG Class A and CNYG Class B common stock					(162,806)	(160,083)	(161,004)
Adjustments to noncontrolling interests					376	1,840	897
Balance	823,103		885,601		823,103	885,601	972,274
Paid-in Capital | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							240
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(4,546,299)		(5,011,960)	(4,546,299)	(5,011,960)	(5,245,483)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					311,439	465,661	233,523
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Proceeds from exercise of options and issuance of restricted shares					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Treasury stock acquired from forfeiture and acquisition of restricted shares					0	0	0
Treasury stock acquired through share repurchase program							0
Tax withholding associated with shares issued for equity-based compensation						0
Excess tax benefit on share-based awards					0	0
Dividends on CNYG Class A and CNYG Class B common stock					0	0	0
Adjustments to noncontrolling interests					0	0	0
Balance	(4,234,860)		(4,546,299)		(4,234,860)	(4,546,299)	(5,011,960)
Accumulated Deficit | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(1,584,404)		(1,572,134)	(1,584,404)	(1,572,134)	(1,363,698)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Proceeds from exercise of options and issuance of restricted shares					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Treasury stock acquired from forfeiture and acquisition of restricted shares					(6,617)	(12,270)	(19,836)
Treasury stock acquired through share repurchase program							(188,600)
Tax withholding associated with shares issued for equity-based compensation						0
Excess tax benefit on share-based awards					0	0
Dividends on CNYG Class A and CNYG Class B common stock					0	0	0
Adjustments to noncontrolling interests					0	0	0
Balance	(1,591,021)		(1,584,404)		(1,591,021)	(1,584,404)	(1,572,134)
Treasury Stock | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(42,694)		(30,763)	(42,694)	(30,763)	(21,468)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					459	(11,931)	(9,295)
Proceeds from exercise of options and issuance of restricted shares					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Treasury stock acquired from forfeiture and acquisition of restricted shares					0	0	0
Treasury stock acquired through share repurchase program							0
Tax withholding associated with shares issued for equity-based compensation						0
Excess tax benefit on share-based awards					0	0
Dividends on CNYG Class A and CNYG Class B common stock					0	0	0
Adjustments to noncontrolling interests					0	0	0
Balance	(42,235)		(42,694)		(42,235)	(42,694)	(30,763)
Accumulated Other Comprehensive Loss | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
Total Stockholders'/Member's Deficiency
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(5,284,330)		(5,639,164)	(5,284,330)	(5,639,164)	(5,575,855)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					311,439	465,661	233,523
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					459	(11,931)	(9,295)
Proceeds from exercise of options and issuance of restricted shares					55,330	18,196	18,722
Recognition of equity-based stock compensation arrangements					44,335	52,777	62,039
Treasury stock acquired from forfeiture and acquisition of restricted shares					(6,608)	(12,262)	(19,831)
Treasury stock acquired through share repurchase program							(188,600)
Tax withholding associated with shares issued for equity-based compensation						(644)
Excess tax benefit on share-based awards					336	1,280
Dividends on CNYG Class A and CNYG Class B common stock					(162,806)	(160,083)	(161,004)
Adjustments to noncontrolling interests					376	1,840	897
Balance	(5,041,469)		(5,284,330)		(5,041,469)	(5,284,330)	(5,639,164)
Total Stockholders'/Member's Deficiency | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							240
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		786		1,158	786	1,158	1,791
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					1,007	1,052	1,638
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Proceeds from exercise of options and issuance of restricted shares					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Treasury stock acquired from forfeiture and acquisition of restricted shares					0	0	0
Treasury stock acquired through share repurchase program							0
Tax withholding associated with shares issued for equity-based compensation						0
Excess tax benefit on share-based awards					0	0
Dividends on CNYG Class A and CNYG Class B common stock					0	0	0
Adjustments to noncontrolling interests					(1,014)	(1,424)	(2,271)
Balance	779		786		779	786	1,158
Noncontrolling Interest | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
CSC Holdings, LLC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(2,643,286)		(2,850,615)	(2,643,286)	(2,850,615)	(3,413,152)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member	91,132	129,384	85,645	24,947	462,008	620,075	386,261
Net income attributable to noncontrolling interests					1,007	1,052	1,638
Pension and postretirement plan liability adjustments, net of income taxes					459	(11,931)	(9,295)
Recognition of equity-based stock compensation arrangements					44,335	52,777	62,039
Distributions to Cablevision					(396,382)	(501,224)	(671,809)
Contributions from Cablevision							735,000
Excess tax benefit on share-based awards					4,978	46,164	65,420
Impact of purchase of Cablevision senior notes held by Newsday Holdings						(296)
Adjustments to noncontrolling interests					(638)	712	(1,374)
Balance	(2,527,519)		(2,643,286)		(2,527,519)	(2,643,286)	(2,850,615)
CSC Holdings, LLC | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							(5,343)
CSC Holdings, LLC | Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(2,486,073)		(3,106,148)	(2,486,073)	(3,106,148)	(3,492,409)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					462,008	620,075	386,261
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Distributions to Cablevision					0	0	0
Contributions from Cablevision							0
Excess tax benefit on share-based awards					0	0	0
Impact of purchase of Cablevision senior notes held by Newsday Holdings						0
Adjustments to noncontrolling interests					0	0	0
Balance	(2,024,065)		(2,486,073)		(2,024,065)	(2,486,073)	(3,106,148)
CSC Holdings, LLC | Accumulated Deficit | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
CSC Holdings, LLC | Senior Notes due from Cablevision
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(611,455)		(753,717)	(611,455)	(753,717)	(753,717)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Distributions to Cablevision					0	0	0
Contributions from Cablevision							0
Excess tax benefit on share-based awards					0	0	0
Impact of purchase of Cablevision senior notes held by Newsday Holdings						142,262
Adjustments to noncontrolling interests					0	0	0
Balance	(611,455)		(611,455)		(611,455)	(611,455)	(753,717)
CSC Holdings, LLC | Senior Notes due from Cablevision | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
CSC Holdings, LLC | Other Member's Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		496,150		1,038,855	496,150	1,038,855	852,651
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Recognition of equity-based stock compensation arrangements					44,335	52,777	62,039
Distributions to Cablevision					(396,382)	(501,224)	(671,809)
Contributions from Cablevision							735,000
Excess tax benefit on share-based awards					4,978	46,164	65,420
Impact of purchase of Cablevision senior notes held by Newsday Holdings						(142,558)
Adjustments to noncontrolling interests					376	2,136	897
Balance	149,457		496,150		149,457	496,150	1,038,855
CSC Holdings, LLC | Other Member's Equity | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							(5,343)
CSC Holdings, LLC | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(42,694)		(30,763)	(42,694)	(30,763)	(21,468)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					459	(11,931)	(9,295)
Recognition of equity-based stock compensation arrangements					0	0	0
Distributions to Cablevision					0	0	0
Contributions from Cablevision							0
Excess tax benefit on share-based awards					0	0	0
Impact of purchase of Cablevision senior notes held by Newsday Holdings						0
Adjustments to noncontrolling interests					0	0	0
Balance	(42,235)		(42,694)		(42,235)	(42,694)	(30,763)
CSC Holdings, LLC | Accumulated Other Comprehensive Loss | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							0
CSC Holdings, LLC | Total Stockholders'/Member's Deficiency
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		(2,644,072)		(2,851,773)	(2,644,072)	(2,851,773)	(3,414,943)
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					462,008	620,075	386,261
Net income attributable to noncontrolling interests					0	0	0
Pension and postretirement plan liability adjustments, net of income taxes					459	(11,931)	(9,295)
Recognition of equity-based stock compensation arrangements					44,335	52,777	62,039
Distributions to Cablevision					(396,382)	(501,224)	(671,809)
Contributions from Cablevision							735,000
Excess tax benefit on share-based awards					4,978	46,164	65,420
Impact of purchase of Cablevision senior notes held by Newsday Holdings						(296)
Adjustments to noncontrolling interests					376	2,136	897
Balance	(2,528,298)		(2,644,072)		(2,528,298)	(2,644,072)	(2,851,773)
CSC Holdings, LLC | Total Stockholders'/Member's Deficiency | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							(5,343)
CSC Holdings, LLC | Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		786		1,158	786	1,158	1,791
Net income attributable to Cablevision Systems Corporation stockholders/CSC Holdings, LLC's sole member					0	0	0
Net income attributable to noncontrolling interests					1,007	1,052	1,638
Pension and postretirement plan liability adjustments, net of income taxes					0	0	0
Recognition of equity-based stock compensation arrangements					0	0	0
Distributions to Cablevision					0	0	0
Contributions from Cablevision							0
Excess tax benefit on share-based awards					0	0	0
Impact of purchase of Cablevision senior notes held by Newsday Holdings						0
Adjustments to noncontrolling interests					(1,014)	(1,424)	(2,271)
Balance	779		786		779	786	1,158
CSC Holdings, LLC | Noncontrolling Interest | AMC Networks
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments relating to distribution of AMC Networks							$ 0