GOODWILL, RADIO BROADCASTING LICENSES AND OTHER INTANGIBLE ASSETS - Goodwill Valuation Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
GOODWILL AND RADIO BROADCASTING LICENSES
Gross goodwill	$ 378,079	$ 377,989
Accumulated impairment losses	(132,507)	(115,095)
Additions		90
Impairments	(5,800)	(17,412)
Net goodwill	239,772	245,572
Radio Broadcasting Segment [Member]
GOODWILL AND RADIO BROADCASTING LICENSES
Gross goodwill	155,000	154,910
Accumulated impairment losses	(101,848)	(84,436)
Additions	0	90
Impairments	0	(17,412)
Net goodwill	53,152	53,152
Reach Media Segment [Member]
GOODWILL AND RADIO BROADCASTING LICENSES
Gross goodwill	30,468	30,468
Accumulated impairment losses	(16,114)	(16,114)
Additions	0	0
Impairments	0	0
Net goodwill	14,354	14,354
Digital Segment [Member]
GOODWILL AND RADIO BROADCASTING LICENSES
Gross goodwill	27,567	27,567
Accumulated impairment losses	(14,545)	(14,545)
Additions	0	0
Impairments	(5,800)	0
Net goodwill	7,222	13,022
Cable Television Segment [Member]
GOODWILL AND RADIO BROADCASTING LICENSES
Gross goodwill	165,044	165,044
Accumulated impairment losses	0	0
Additions	0	0
Impairments	0	0
Net goodwill	$ 165,044	$ 165,044