| Cover | Mar. 22, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 22, 2022 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-31361 |
| Entity Registrant Name | BioDelivery Sciences International, Inc. |
| Entity Central Index Key | 0001103021 |
| Entity Tax Identification Number | 35-2089858 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 4131 ParkLake Ave., Suite 225 |
| Entity Address, City or Town | Raleigh |
| Entity Address, State or Province | NC |
| Entity Address, Postal Zip Code | 27612 |
| City Area Code | 919 |
| Local Phone Number | 582-9050 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock, par value $0.001 |
| Trading Symbol | BDSI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
