PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 171,798	$ 171,682
Less: Accumulated depreciation and amortization	(147,405)	(145,594)
Property, Plant and Equipment, Net, Total	24,393	26,088
Land and improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 4,652	3,491
Property, Plant and Equipment, Estimated Useful Lives	0 years
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,756	2,754
Property, Plant and Equipment, Estimated Useful Lives	31 years
Transmitters and towers [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 40,705	41,854
Transmitters and towers [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	15 years
Transmitters and towers [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	7 years
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 60,391	60,872
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	7 years
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 9,322	9,699
Property, Plant and Equipment, Estimated Useful Lives	6 years
Software and web development [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 28,789	27,330
Property, Plant and Equipment, Estimated Useful Lives	3 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 24,957	25,407
Property, Plant and Equipment, Estimated Useful Lives	Lease Term
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 226	$ 275
Property, Plant and Equipment, Estimated Useful Lives	0 years