ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Net Revenue	$ 113,542	$ 91,912	$ 76,008	$ 94,875	$ 105,854	$ 111,055	$ 121,571	$ 98,449	$ 376,337	$ 436,929
Radio Advertising [Member]
Net Revenue									137,849	193,318
Political Advertising [Member]
Net Revenue									22,484	1,445
Digital Advertising [Member]
Net Revenue									34,131	31,912
Cable Television Advertising [Member]
Net Revenue									79,732	79,776
Cable Television Affiliate Fees [Member]
Net Revenue									99,489	105,071
Event Revenues & Other [Member]
Net Revenue									$ 2,652	$ 25,407