Debt instrument interest only payment term.

No definition available.

Name:	bdsi_DebtInstrumentInterestOnlyPaymentTerm
Namespace Prefix:	bdsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument interest only payment term threshold.

+ References

No definition available.

+ Details

Name:	bdsi_DebtInstrumentInterestOnlyPaymentTermThreshold
Namespace Prefix:	bdsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument interest rate stated interest only period percentage.

+ References

No definition available.

+ Details

Name:	bdsi_DebtInstrumentInterestRateStatedInterestOnlyPeriodPercentage
Namespace Prefix:	bdsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument prepayment fee after year five.

+ References

No definition available.

+ Details

Name:	bdsi_DebtInstrumentPrepaymentFeeAfterYearFive
Namespace Prefix:	bdsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The Distribution Agreement covers distribution within the entire United States, has an initial term after the launch of the product and one initial automatic renewal period

+ References

No definition available.

+ Details

Name:	bdsi_FirstAutomaticRenewalOption
Namespace Prefix:	bdsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Initial term.

+ References

No definition available.

+ Details

Name:	bdsi_InitialTerm
Namespace Prefix:	bdsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

License termination effective date.

+ References

No definition available.

+ Details

Name:	bdsi_LicenseTerminationEffectiveDate
Namespace Prefix:	bdsi_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility additional borrowing capacity upon contingent milestone achievement.

+ References

No definition available.

+ Details

Name:	bdsi_LineOfCreditFacilityAdditionalBorrowingCapacityUponContingentMilestoneAchievement
Namespace Prefix:	bdsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of credit facility second draw borrowing capacity upon contingent milestone achievement.

+ References

No definition available.

+ Details

Name:	bdsi_LineOfCreditFacilitySecondDrawBorrowingCapacityUponContingentMilestoneAchievement
Namespace Prefix:	bdsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of warrants.

+ References

No definition available.

+ Details

Name:	bdsi_NumberOfWarrants
Namespace Prefix:	bdsi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Prepayment period of outstanding principal and accrued unpaid interest.

+ References

No definition available.

+ Details

Name:	bdsi_PrepaymentPeriodOfOutstandingPrincipalAndAccruedUnpaidInterest
Namespace Prefix:	bdsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Remaining line of credit after deducting loan origination cost broker and other fees.

+ References

No definition available.

+ Details

Name:	bdsi_RemainingLineOfCreditAfterDeductingLoanOriginationCostBrokerAndOtherFees
Namespace Prefix:	bdsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The Distribution Agreement covers distribution within the entire United States, has an initial term period after the launch of the product, followed by an initial automatic renewal period and subsequent additional automatic one-year renewal periods thereafter, which will occur unless either party provides written notice of termination an agreed upon period of time prior to the expiration of the initial term or any renewal term.

+ References

No definition available.

+ Details

Name:	bdsi_SubsequentAutomaticRenewalOption
Namespace Prefix:	bdsi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Termination agreement date.

+ References

No definition available.

+ Details

Name:	bdsi_TerminationAgreementDate
Namespace Prefix:	bdsi_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=bdsi_TrancheOneMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_DebtInstrumentAxis=bdsi_TrancheTwoMember
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Subsequent events - Additional Information (Detail)			12 Months Ended
Subsequent events - Additional Information (Detail)	Feb. 21, 2017 USD ($) Warrant $ / shares shares	Dec. 07, 2016	Dec. 31, 2016 $ / shares	Jul. 31, 2016 $ / shares	Dec. 31, 2014 shares
Subsequent Event [Line Items]
Warrants issued to purchase shares of common stock \| shares					2,217,520
Mid Cap Financial Trust [Member]
Subsequent Event [Line Items]
Warrants exercisable period \| $ / shares			$ 3.53	$ 4.20
Subsequent Event [Member]
Subsequent Event [Line Items]
Remainder of borrowings	$ 14,000,000
Subsequent Event [Member] \| Mid Cap Financial Trust [Member]
Subsequent Event [Line Items]
Amount of initial loan proceeds	29,400,000
Endo Agreement [Member]
Subsequent Event [Line Items]
Termination agreement date			Dec. 07, 2016
License termination effective date			Jan. 06, 2017
Distribution Agreement [Member] \| Belbuca [Member]
Subsequent Event [Line Items]
Initial Term		3 years
Renewal term option for one year		2 years
Renewal term option for two years		1 year
CRG [Member]
Subsequent Event [Line Items]
License termination effective date			Feb. 21, 2017
CRG [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Borrowings outstanding	45,000,000
Additional borrowing capacity upon milestone achievement	30,000,000
Second draw borrowing capacity upon milestone achievement	$ 5,000,000
Loan agreement term	6 years
Loan agreement interest only term	3 years
Loan agreement interest only term threshold	4 years
Agreement maturity date	Dec. 31, 2022
Interest on borrowings	12.50%
Interest on borrowings, interest only period percentage	3.50%
Effective interest on borrowings	9.00%
Prepayment period of outstanding principal and accrued unpaid interest	5 years
Prepayment fee after	$ 0
Additional interest rate	4.00%
Number of warrants \| Warrant	5
Warrants issued to purchase shares of common stock \| shares	1,701,582
Warrants exercisable period \| $ / shares	$ 2.38
CRG [Member] \| Subsequent Event [Member] \| Tranche One [Member]
Subsequent Event [Line Items]
Additional borrowing capacity upon milestone achievement	$ 15,000,000
CRG [Member] \| Subsequent Event [Member] \| Tranche Two [Member]
Subsequent Event [Line Items]
Additional borrowing capacity upon milestone achievement	$ 15,000,000