INCOME TAXES - Expected And Reported Income Taxes (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%
Computed tax expense at federal statutory rates on income before income taxes	$ (68,602)	$ (80,432)	$ (77,016)
State income tax expense, net of federal benefit	(18,538)	13,661	(4,779)
Goodwill impairment	0	98,910	64,465
Valuation allowance current year activity	0	(321)	(2,593)
Tax impact of share-based awards	1,424	950	872
Transaction costs	19	105	391
U.S. federal income tax reform	0	0	883
Taxable gain on sale of radio stations	0	0	5,511
Nondeductible expenses and other	1,818	4,333	8,113
Total income taxes (benefit)	$ (83,879)	$ 37,206	$ (4,153)