Cover Document
| Cover Document | Jan. 22, 2021 |
| Cover [Abstract] | |
| Entity Central Index Key | 0001018399 |
| Document Type | 8-K |
| Document Period End Date | Jan. 19, 2021 |
| Entity Registrant Name | ENTERPRISE BANCORP, INC. |
| Entity Incorporation, State or Country Code | MA |
| Entity File Number | 001-33912 |
| Entity Tax Identification Number | 04-3308902 |
| Entity Address, Address Line One | 222 Merrimack Street |
| Entity Address, City or Town | Lowell, |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 01852 |
| City Area Code | (978) |
| Local Phone Number | 459-9000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.01 par value per share |
| Trading Symbol | EBTC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Current Fiscal Year End Date | --12-31 |