REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Net revenues	$ 304,464	$ 175,868	$ 545,229	$ 472,898
Spot revenues
Disaggregation of Revenue [Line Items]
Net revenues	202,797	102,466	356,998	305,880
Digital revenues
Disaggregation of Revenue [Line Items]
Net revenues	58,435	41,340	108,368	83,850
Network revenues
Disaggregation of Revenue [Line Items]
Net revenues	20,603	16,687	38,173	37,982
Sponsorships and event revenues
Disaggregation of Revenue [Line Items]
Net revenues	10,771	7,239	19,929	24,095
Other revenues
Disaggregation of Revenue [Line Items]
Net revenues	$ 11,858	$ 8,136	$ 21,761	$ 21,091