Document and Entity Information (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Feb. 29, 2012 Common Class A Member	Feb. 29, 2012 Common Class B Member
Document Information [Line Items]
Document Type	10-K
Document Period End Date	Dec. 31, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY
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 Public Float	$ 0
Entity Common Stock Shares Outstanding		31,083,087	7,197,532