The year patents begin to expire.

No definition available.

Name:	bdsi_PatentExpirationYearStart
Namespace Prefix:	bdsi_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue earned during the period arising from products sold or services provided under the terms of a contract, not elsewhere specified in the taxonomy. May include government contracts, construction contracts, and any other contract related to a particular project or product.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_ContractsRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1)

-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A

+ Details

Name:	us-gaap_DeferredRevenueRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RevenueRecognitionMilestoneMethodLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=bdsi_MilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

License and Development Agreements - Meda License, Development and Supply Agreements - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Oct. 31, 2009	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue Recognition, Milestone Method [Line Items]
Patent expiration year				2020
Contract revenues		$ 351	$ 10,675	$ 11,759	$ 21,959
U.S. [Member]
Revenue Recognition, Milestone Method [Line Items]
Aggregate milestones and services revenue recognized	$ 59,700
U.S. [Member] \| Milestones [Member]
Revenue Recognition, Milestone Method [Line Items]
Contract revenues				$ 1,000