RESTRUCTURING AND IMPAIRMENT CHARGES (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Employee	Dec. 31, 2014 Employee
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)	$ 2,480,000	$ 23,550,000	$ (770,000)
Asset Impairment Charges [Abstract]
Impairment charges related to goodwill	0	0	0
Impairment charges related to other long-lived assets	425,000	10,997,000	829,000
Trademarks
Asset Impairment Charges [Abstract]
Impairment charges related to trademarks	200,000	25,100,000	13,000,000
Subscriber relationships
Asset Impairment Charges [Abstract]
Impairment charges	5,631,000
Advertiser relationships
Asset Impairment Charges [Abstract]
Impairment charges		12,358,000
2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		24,084,000
Payments and other	(13,448,000)	(9,342,000)
Accrual balance at end of period	1,294,000	14,742,000		14,742,000	1,294,000
Prior Restructuring Plans
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)	1,984,000	(534,000)	(770,000)
Employee Severance | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		22,879,000
Early Lease Termination | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		1,205,000
Cable | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		11,283,000
Payments and other	(2,722,000)	(8,556,000)
Accrual balance at end of period	5,000	2,727,000		2,727,000	5,000
Cable | Employee Severance
Restructuring [Abstract]
Number of positions eliminated				234
Cable | Employee Severance | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		11,283,000
Cable | Early Lease Termination | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		0
Lightpath | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		1,558,000
Payments and other	(311,000)	(628,000)
Accrual balance at end of period	619,000	930,000		930,000	619,000
Lightpath | Employee Severance
Restructuring [Abstract]
Number of positions eliminated				16
Lightpath | Employee Severance | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		1,558,000
Lightpath | Early Lease Termination | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		0
Other | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		11,243,000
Payments and other	(10,415,000)	(158,000)
Accrual balance at end of period	670,000	11,085,000		11,085,000	670,000
Other | Employee Severance
Restructuring [Abstract]
Number of positions eliminated				191
Other | Employee Severance | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		10,038,000
Other | Early Lease Termination | 2013 Restructuring Plan
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)		1,205,000		1,205,000
Newsday | Employee Severance | 2014 Restructuring Plan
Restructuring [Abstract]
Number of positions eliminated					59
Accrued Restructuring Liability [Roll Forward]
Restructuring expense (credits)					$ 3,280,000