Document and Entity Information	9 Months Ended
	Sep. 30, 2011	Oct. 31, 2011 Common Class A Member	Oct. 31, 2011 Common Class B Member
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Sep. 30, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
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	No
Entity Common Stock Shares Outstanding		30,888,832	7,367,532