REVENUE - Disaggregation of Revenue - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Abstract]
Broadcast revenues	$ 380,124	$ 126,441	$ 685,843	$ 229,755
Event and other revenues	28,252	10,716	50,861	16,137
Trade and barter revenues	3,272	1,244	6,770	2,322
Agency commissions	(39,524)	(13,431)	(70,790)	(24,243)
Sales Revenue, Net	$ 372,124	$ 124,970	$ 672,684	$ 223,971