REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Disaggregation Of Revenue [Abstract] | |||
| Broadcast revenues | $ 1,327,803 | $ 530,553 | $ 428,266 |
| Event and other revenues | 115,399 | 51,434 | 31,805 |
| Trade and barter revenues | 19,365 | 10,897 | $ 4,700 |
| Agency commissions | $ 0 | $ 0 | |