GOODWILL, RADIO BROADCASTING LICENSES AND OTHER INTANGIBLE ASSETS - Radio Broadcasting Licenses (Details) - Radio broadcasting licenses - USD ($) $ in Thousands			3 Months Ended						12 Months Ended
	Oct. 01, 2023	Oct. 01, 2022	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2023	Dec. 31, 2022
Schedule of Goodwill, Radio Broadcasting Licenses And Other Intangible Assets [Line Items]
Impairment of indefinite lived intangible assets	$ 0	$ 7,400	$ 5,000	$ 85,400	$ 22,100	$ 16,800	$ 15,500	$ 10,600	$ 129,278	$ 33,443
Discount rate	10.00%	9.50%		10.00%	9.50%		9.50%	9.50%
Terminal growth rate range	(0.50%)		(0.50%)	(0.50%)					(0.50%)
Minimum
Schedule of Goodwill, Radio Broadcasting Licenses And Other Intangible Assets [Line Items]
Revenue growth rate range	(1.70%)	0.00%	(2.30%)	0.00%	0.30%		0.30%	0.70%	(2.30%)
Terminal growth rate range		0.30%			0.30%		0.30%	0.70%
Mature market share range	5.30%	6.80%	5.20%	5.30%	0.90%		6.80%	6.90%	5.20%
Mature operating profit margin range	17.00%	27.20%	17.00%	17.00%	18.80%		28.30%	28.30%	17.00%
Maximum
Schedule of Goodwill, Radio Broadcasting Licenses And Other Intangible Assets [Line Items]
Revenue growth rate range	0.00%	1.70%	0.80%	(1.70%)	1.40%		1.60%	2.40%	0.80%
Terminal growth rate range		0.80%			0.80%		0.80%	1.00%
Mature market share range	29.50%	27.60%	30.00%	29.50%	28.80%		27.60%	25.60%	30.00%
Mature operating profit margin range	33.50%	34.60%	31.90%	33.50%	34.60%		36.10%	36.10%	31.90%