INTANGIBLE ASSETS AND GOODWILL - Changes in carrying value of broadcasting licenses (Details) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2019 |
Dec. 31, 2018 |
|
| Changes in Intangible assets [Line Items] | ||
| Assets held for sale | $ (1,891) | $ (19,603) |
| Radio Broadcasting Licences [Member] | ||
| Changes in Intangible assets [Line Items] | ||
| Beginning of period balance | 2,516,625 | 2,649,959 |
| Impairment loss | 0 | (148,564) |
| Ending period balance | 2,518,261 | 2,516,625 |
| Radio Broadcasting Licences [Member] | Cumulus Exchange [Member] | ||
| Changes in Intangible assets [Line Items] | ||
| Dispositions | (17,940) | (24,901) |
| Radio Broadcasting Licences [Member] | 2019 Cumulus Exchange [Member] | ||
| Changes in Intangible assets [Line Items] | ||
| Beginning of period balance | 2,516,625 | |
| Acquisition of radio stations | $ 19,576 | 40,131 |
| Ending period balance | $ 2,516,625 |