GOODWILL AND RADIO BROADCASTING LICENSES (Details) - Radio Broadcasting Licenses [Member] - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Schedule Of Goodwill, Radio Broadcasting Licenses And Other Intangible Assets [Line Items]
Pre-tax impairment charge	[1]	$ 16.4	$ 0.0
Discount Rate	[1]	9.00%	9.00%
Minimum [Member]
Schedule Of Goodwill, Radio Broadcasting Licenses And Other Intangible Assets [Line Items]
Year 1 Market Revenue Growth Rate Range	[1]	(5.00%)	0.30%
Long-term Market Revenue Growth Rate Range (Years 6 - 10)	[1]	0.50%	0.50%
Mature Market Share Range	[1]	6.90%	8.90%
Operating Profit Margin Range	[1]	31.00%	31.30%
Maximum [Member]
Schedule Of Goodwill, Radio Broadcasting Licenses And Other Intangible Assets [Line Items]
Year 1 Market Revenue Growth Rate Range	[1]	2.00%	0.50%
Long-term Market Revenue Growth Rate Range (Years 6 - 10)	[1]	1.50%	1.00%
Mature Market Share Range	[1]	25.80%	14.20%
Operating Profit Margin Range	[1]	47.00%	34.10%

[1] Reflects changes only to the key assumptions used in the interim testing for certain units of accounting.