Document and Entity Information - USD ($)	6 Months Ended
	Jun. 30, 2018	Jul. 27, 2018
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Entity Registrant Name	Entercom Communications Corp.
Entity Central Index Key	0001067837
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well Known Seasoned Issuer	Yes
Entity Public Float	$ 1,076,421,960
Trading Symbol	ETM
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock Shares Outstanding		138,472,787
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock Shares Outstanding		4,045,199