| Document And Entity Information | Feb. 17, 2021 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Bank of Commerce Holdings |
| Document, Type | 8-K |
| Document, Period End Date | Feb. 17, 2021 |
| Entity, Incorporation, State or Country Code | CA |
| Entity, File Number | 000-25135 |
| Entity, Tax Identification Number | 94-2823865 |
| Entity, Address, Address Line One | 555 Capitol Mall |
| Entity, Address, Address Line Two | Suite 1255 |
| Entity, Address, City or Town | Sacramento |
| Entity, Address, State or Province | CA |
| Entity, Address, Postal Zip Code | 95814 |
| City Area Code | 800 |
| Local Phone Number | 421-2575 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | BOCH |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0000702513 |
