ACQUISITIONS, DIVESTITURES AND PRO FORMA SUMMARY (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2016	Nov. 17, 2017
Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 0	$ 0
Purchase price allocation [Abstract]
Property Plant And Equipment Net	327,901		$ 317,030
The expense recognized in the consolidated statement of income as merger and acquisition costs [Abstract]
Merger and acquisition costs and restructuring charges	9	1,383
Restructuring Charges	1,014	1,481		$ 0
Transition Services Costs	0	0		0
Other Restructuring Costs	321	491		0
Lease Abandonment Costs	0	257		0
Changes in Estimates	0	0
Workforce Reduction	693	590		0
Costs to Exit Duplicative Contracts	0	143		$ 0
Unaudited Pro Forma Summary Of Financial Information
Net revenues	309,005	305,425
Net income	$ 3,125	$ (13,353)
Net income per common share - basic	$ 0.02	$ (0.1)
Net income per common share - diluted	$ 0.02	$ (0.1)
Net income, available to common shareholders	$ 3,125	$ (13,353)
ProFormaWeightedAverageSharesOutstandingDiluted	138,523,371	138,939,309
WeightedAverageBasicSharesOutstandingProForma	138,099,180	138,939,309
Income (Loss) from Continuing Operations, Per Outstanding Share, Total	$ 0.02	$ (0.1)
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$ 0	$ 0
Weighted Average Number Of Shares Outstanding Basic	138,099,180	138,939,309
Weighted Average Number Of Diluted Shares Outstanding	138,523,371	138,939,309
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 0	$ 0
Income Loss From Discontinued Operations Net Of Tax	$ 0	$ 328
CBS Radio [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Net assets acquired					$ 1,170,000
Total liabilities acquired					1,390,000
Unaudited Pro Forma Summary Of Financial Information
CBS Radio Total Consideration					$ 2,560,000
CBS Radio [Member]
Unaudited Pro Forma Summary Of Financial Information
Shares Issued Pursuant to Acquisition			101,407,494
Cumulus Transaction - CBS Radio Member | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Unaudited Pro Forma Summary Of Financial Information
Gain Loss on sale of station			$ 400
ProceedsFromDivestitureOfBusinesses			141,000
Emmis [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Acquisition [Line Items]
Payments to Acquire Businesses, Gross			15,000
Purchase price allocation [Abstract]
Total intangible assets			13,442
Total assets			15,000
Net assets acquired			$ 15,000
Unaudited Pro Forma Summary Of Financial Information
Discount Rates			9.00%
Emmis [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain] | MeasurementInputLongTermRevenueGrowthRateMemberMember [Member]
Unaudited Pro Forma Summary Of Financial Information
LongTermRevenueGrowthRate			1.00%
Emmis [Member] | Equipment [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Property, Plant and Equipment, Gross			$ 1,558
Emmis [Member] | Total Tangible Property Member [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Property, Plant and Equipment, Gross			1,558
Emmis [Member] | Radio Broadcasting Licences [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			12,785
Emmis [Member] | Goodwill [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			332
Emmis [Member] | Advertiser lists and customer relationships [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			207
Emmis [Member] | Acquired advertising contracts [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			114
Emmis [Member] | Other Noncurrent Assets [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			4
Jerry Lee [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Acquisition [Line Items]
Payments to Acquire Businesses, Gross			57,500
Purchase price allocation [Abstract]
Total intangible assets			55,453
Total assets			56,434
Net assets acquired			$ 56,434
Unaudited Pro Forma Summary Of Financial Information
Discount Rates			9.00%
LongTermRevenueGrowthRate			1.00%
Jerry Lee [Member] | Maximum [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Tangible assets amortization period			7 years
Jerry Lee [Member] | Minimum [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Tangible assets amortization period			3 years
Jerry Lee [Member] | Equipment [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total tangible assets			$ 981
Jerry Lee [Member] | Equipment [Member] | Minimum [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Tangible assets amortization period			3 years
Jerry Lee [Member] | Total Tangible Property Member [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total tangible assets			$ 981
Jerry Lee [Member] | Radio Broadcasting Licences [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			27,346
Jerry Lee [Member] | Goodwill [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			24,396
Jerry Lee [Member] | Acquired advertising contracts [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			$ 477
Jerry Lee [Member] | Acquired advertising contracts [Member] | Maximum [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Intangible assets amortization period			1 year
Jerry Lee [Member] | Acquired advertising contracts [Member] | Minimum [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Intangible assets amortization period			1 year
Jerry Lee [Member] | Other Noncurrent Assets [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Purchase price allocation [Abstract]
Total intangible assets			$ 3,234
Beasley - WXTU [Member] | CurrentLiabilitiesDomain [Domain] | LongTermLiabilitiesDomain [Domain]
Unaudited Pro Forma Summary Of Financial Information
Gain Loss on sale of station			4,400
ProceedsFromDivestitureOfBusinesses			$ 38,000