| Cover | Jun. 10, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jun. 10, 2021 |
| Entity Registrant Name | Bryn Mawr Bank Corporation |
| Entity Central Index Key | 0000802681 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | PA |
| Entity File Number | 001-35746 |
| Entity Tax Identification Number | 23-2434506 |
| Entity Address, Address Line One | 801 Lancaster Avenue |
| Entity Address, City or Town | Bryn Mawr |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19010 |
| City Area Code | 610 |
| Local Phone Number | 525-1700 |
| Title of 12(b) Security | Common Stock, $1 par value |
| Trading Symbol | BMTC |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
