ACQUISITIONS, DIVESTITURES AND PRO FORMA SUMMARY (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Jan. 06, 2017
Acquisition [Line Items]
Payments to Acquire Businesses, Gross			$ 24,000	$ 92
Purchase price allocation [Abstract]
Total intangible assets			17,174		$ 0
Property Plant And Equipment Net	$ 67,432		67,432		$ 63,375
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Merger and acquisition costs	24,925	$ 670	24,925	670		$ 6,836
Merger and acquisition costs and restructuring charges	8,825	670	24,925	670
Restructuring Charges			0	0		0
Unaudited Pro Forma Summary Of Financial Information
Net revenues	122,299	125,441	346,270	351,697
Net income	$ 4,100	$ 11,364	$ 1,516	$ 23,946
Net income per common share - basic	$ 0.09	$ 0.28	$ (0.01)	$ 0.59
Net income per common share - diluted	$ 0.09	$ 0.27	$ (0.01)	$ 0.57
Net income, available to common shareholders	$ 3,437	$ 10,838	$ (247)	$ 22,595
CBS Ownership Percentage Post Merger	72.00%		72.00%
CBS Radio Total Consideration	$ 1,160,000		$ 1,160,000
ETM Share Price on Reporting Date	$ 11.45		$ 11.45
Radio New Common Stock Issued by CBS Radio			101,407,494
Par Value - Radio Series 1 Common Stock	$ 0.01		$ 0.01
Adjustment [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			$ 0	0		0
Lease abandonment expense [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			0
Lease abandonment expense [Member] | Adjustment [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			0	0		0
Cost Of Terminating Contracts [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			0
Cost Of Terminating Contracts [Member] | Adjustment [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			0	0		0
One Time Termination Expenses [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			0
One Time Termination Expenses [Member] | Adjustment [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Restructuring Charges			0	0		$ 0
LFM [Member]
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Merger and acquisition costs and restructuring charges			24,925	670
KRWZAM [Member]
Unaudited Pro Forma Summary Of Financial Information
Expected gain on sale of station				300
ProceedsFromDivestitureOfBusinesses				$ 3,800
Charlotte [Member]
Acquisition [Line Items]
Payments to Acquire Businesses, Gross			$ 24,000
Purchase price allocation [Abstract]
Total assets							$ 24,996
Net assets acquired							24,000
Total liabilities acquired							996
Property, Plant and Equipment, Gross							7,325
Unaudited Pro Forma Summary Of Financial Information
Discount Rates			9.00%
Charlotte [Member] | Minimum [Member]
Unaudited Pro Forma Summary Of Financial Information
Fair Value Inputs Long Term Revenue Growth Rate			1.00%
Charlotte [Member] | Unfavorable lease liability [Member]
Purchase price allocation [Abstract]
Total current liabilities							735
Charlotte [Member] | OtherNoncurrentLiabilitiesMember
Purchase price allocation [Abstract]
Other long-term liabilities							261
Charlotte [Member] | Equipment [Member]
Purchase price allocation [Abstract]
Total tangible assets			$ 4,569
Charlotte [Member] | Equipment [Member] | Maximum [Member]
Purchase price allocation [Abstract]
Tangible assets amortization period			40 years
Charlotte [Member] | Equipment [Member] | Minimum [Member]
Purchase price allocation [Abstract]
Tangible assets amortization period			3 years
Charlotte [Member] | Land [Member]
Purchase price allocation [Abstract]
Total tangible assets			$ 2,539
Charlotte [Member] | Building [Member]
Purchase price allocation [Abstract]
Total tangible assets			$ 217
Charlotte [Member] | Building [Member] | Maximum [Member]
Purchase price allocation [Abstract]
Tangible assets amortization period			25 years
Charlotte [Member] | Building [Member] | Minimum [Member]
Purchase price allocation [Abstract]
Tangible assets amortization period			15 years
Charlotte [Member] | Radio Broadcasting Licences [Member]
Purchase price allocation [Abstract]
Total intangible assets			$ 17,384
Charlotte [Member] | Other Noncurrent Assets [Member]
Purchase price allocation [Abstract]
Intangible assets non amortizable							$ 287
CBS Radio [Member]
Unaudited Pro Forma Summary Of Financial Information
Shares Issued Pursuant to Acquisition			101,407,494
ETM Ownership Percentage Post Merger	28.00%		28.00%
Beasley Transatcion - CBS Radio Merger
Unaudited Pro Forma Summary Of Financial Information
Cash Acquired in Excess of Payments to Acquire Business			$ 12,000