| Document and Entity Information | Nov. 06, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | ENTERCOM COMMUNICATIONS CORP |
| Amendment Flag | false |
| Entity Central Index Key | 0001067837 |
| Document Type | 8-K |
| Document Period End Date | Nov. 6, 2020 |
| Entity Incorporation State Country Code | PA |
| Entity File Number | 001-14461 |
| Entity Tax Identification Number | 23-1701044 |
| Entity Address, Address Line One | 2400 Market Street |
| Entity Address, Address Line Two | 4th Floor |
| Entity Address, City or Town | Philadelphia |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19103 |
| City Area Code | (610) |
| Local Phone Number | 660-5610 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Class A Common Stock, par value $.01 per share |
| Trading Symbol | ETM |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
