INTANGIBLE ASSETS, Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Beginning gross goodwill	$ 598,748
Adjustment in connection with the purchase of noncontrolling interest in Newsday	(2,345)
Ending gross goodwill	596,403
Accumulated impairment losses	(334,058)	$ (334,058)
Goodwill, net of accumulated impairment losses	262,345	264,690
Cable
Goodwill [Roll Forward]
Beginning gross goodwill	234,290
Adjustment in connection with the purchase of noncontrolling interest in Newsday	0
Ending gross goodwill	234,290
Accumulated impairment losses	0	0
Goodwill, net of accumulated impairment losses	234,290
Lightpath
Goodwill [Roll Forward]
Beginning gross goodwill	21,487
Adjustment in connection with the purchase of noncontrolling interest in Newsday	0
Ending gross goodwill	21,487
Accumulated impairment losses	0	0
Goodwill, net of accumulated impairment losses	21,487
Other
Goodwill [Roll Forward]
Beginning gross goodwill	342,971
Adjustment in connection with the purchase of noncontrolling interest in Newsday	(2,345)
Ending gross goodwill	340,626
Accumulated impairment losses	(334,058)	$ (334,058)
Goodwill, net of accumulated impairment losses	$ 6,568