Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Mar. 06, 2020	Jun. 28, 2019	Jun. 29, 2018
Cover page.
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-31361
Entity Registrant Name	BioDelivery Sciences International, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	35-2089858
Entity Address, Address Line One	4131 ParkLake Avenue, 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
Title of 12(b) Security	Common stock, par value $0.001
Trading Symbol	BDSI
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001103021
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		96,344,995
Entity Public Float			$ 359,814,864	$ 338,146,138