INTANGIBLE ASSETS AND GOODWILL - Changes in Carrying Value of Broadcasting Licenses (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2020 |
Dec. 31, 2019 |
|
| Indefinite-lived Intangible Assets [Roll Forward] | ||
| Broadcasting licenses balance as of January 1, | $ 2,508,121 | $ 2,516,625 |
| Dispositions | 0 | (17,940) |
| Acquisition of radio stations | 0 | 19,576 |
| Assets held for sale | 0 | (10,140) |
| Ending period balance | $ 2,508,121 | $ 2,508,121 |