GOODWILL, INDEFINITE-LIVED INTANGIBLE ASSETS AND OTHER INTANGIBLE ASSETS - Change in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net	$ 1,990,746	$ 1,931,093
Acquisitions	133,392	65,053
Measurement period adjustments related to prior year acquisitions	307	40
Disposition of assets	(412)	(5,440)
Goodwill, net	2,124,033	1,990,746
VIEs which are not primary beneficiary
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net	800
Goodwill, net	800	800
Broadcast
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net	1,933,831	1,927,605
Acquisitions	119,426	11,626
Measurement period adjustments related to prior year acquisitions	153	40
Disposition of assets	0	(5,440)
Goodwill, net	2,053,410	1,933,831
Other
Change in the carrying amount of goodwill related to continuing operations
Goodwill, net	56,915	3,488
Acquisitions	13,966	53,427
Measurement period adjustments related to prior year acquisitions	154	0
Disposition of assets	(412)	0
Goodwill, net	$ 70,623	$ 56,915