ASSETS HELD FOR SALE AND DISCONTINUED OPERATIONS - Narrative (Details) $ in Thousands		3 Months Ended						12 Months Ended
	Aug. 02, 2018 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)	Nov. 17, 2017 radio_station
Long Lived Assets Held-for-sale [Line Items]
Proceeds from sale of property, equipment, intangibles and other assets	$ 141,000							$ 29,321	$ 185,761	$ 60,505
Carrying value of disposed assets									19,600
Proceeds from sale					$ 24,500
Gain (loss) on sale or properties					$ 4,500
Other asset impairments							$ 25,600
Net assets held for sale		$ 10,188						10,188	$ 19,603
Sacramento, California
Long Lived Assets Held-for-sale [Line Items]
Number Of Stations In Merger Agreement | radio_station												4
San Diego, California
Long Lived Assets Held-for-sale [Line Items]
Number Of Stations In Merger Agreement | radio_station												4
Bonneville Transaction
Long Lived Assets Held-for-sale [Line Items]
Net assets held for sale							$ 140,300				$ 165,900
Loss on disposition of business	$ (400)					$ 200
Assets exchange Cumulus media
Long Lived Assets Held-for-sale [Line Items]
Gain (loss) on sale or properties				$ (1,800)
Properties in California
Long Lived Assets Held-for-sale [Line Items]
Carrying value of disposed assets				1,100
Gain (loss) on sale or properties			$ (100)
Properties in Miami
Long Lived Assets Held-for-sale [Line Items]
Carrying value of disposed assets			1,900	$ 2,200
Gain (loss) on sale or properties		(400)	$ (100)
Equipment and Broadcasting License in Boston
Long Lived Assets Held-for-sale [Line Items]
Carrying value of disposed assets		$ 10,200						$ 10,200