REVENUE - Disaggregation of Revenue - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Abstract]
Broadcast revenues	$ 284,465	$ 274,453
Event and other revenues	19,526	22,609
Trade and barter revenues	$ 5,014	$ 3,498