Debt instrument additional interest expense fee percentage.

No definition available.

Name:	bdsx_DebtInstrumentAdditionalInterestExpenseFeePercentage
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument back-end facility fee percentage.

+ References

No definition available.

+ Details

Name:	bdsx_DebtInstrumentBackEndFacilityFeePercentage
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument, fee percentage.

+ References

No definition available.

+ Details

Name:	bdsx_DebtInstrumentFeePercentage
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument interest added to principal value.

+ References

No definition available.

+ Details

Name:	bdsx_DebtInstrumentInterestAddedToPrincipalValue
Namespace Prefix:	bdsx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt instrument, percentage of stated interest rate added to principal value of notes payable.

+ References

No definition available.

+ Details

Name:	bdsx_DebtInstrumentPercentageOfStatedInterestRateAddedToPrincipalValueOfNotesPayable
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument, percentage of stated interest rate, paid in cash.

+ References

No definition available.

+ Details

Name:	bdsx_DebtInstrumentPercentageOfStatedInterestRatePaidInCash
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument prepayment penalty percentage.

+ References

No definition available.

+ Details

Name:	bdsx_DebtInstrumentPrepaymentPenaltyPercentage
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Payroll costs excludes compensation of an employee.

+ References

No definition available.

+ Details

Name:	bdsx_PayrollCostsExcludesCompensationOfEmployee
Namespace Prefix:	bdsx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage for non-payroll costs.

+ References

No definition available.

+ Details

Name:	bdsx_PercentageForNonPayrollCosts
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of upper limit of employee salary to reduce forgiveness.

+ References

No definition available.

+ Details

Name:	bdsx_PercentageOfUpperLimitOfEmployeeSalaryToReduceForgiveness
Namespace Prefix:	bdsx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Upper limit of employee salary to reduce forgiveness.

+ References

No definition available.

+ Details

Name:	bdsx_UpperLimitOfEmployeeSalaryToReduceForgiveness
Namespace Prefix:	bdsx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ 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 each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

+ Details

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

- Definition

Amount of outstanding long-term debt or borrowing associated with any securities or credit agreement for which there has been a default in principal, interest, sinking fund, or redemption provisions, or any breach of covenant that existed at the end of the period and subsequently has not been cured.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(c))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

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

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleRemainingDiscountAmortizationPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Identification of the lender and information about a contractual promise to repay a short-term or long-term obligation, which includes borrowings under lines of credit, notes payable, commercial paper, bonds payable, debentures, and other contractual obligations for payment. This may include rationale for entering into the arrangement, significant terms of the arrangement, which may include amount, repayment terms, priority, collateral required, debt covenants, borrowing capacity, call features, participation rights, conversion provisions, sinking-fund requirements, voting rights, basis for conversion if convertible and remarketing provisions. The description may be provided for individual debt instruments, rational groupings of debt instruments, or by debt in total.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120398452&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

+ References

+ Details

Name:	us-gaap_DebtInstrumentFeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- 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

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

- Definition

Fair value portion of warrants not settleable in cash classified as equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=bdsx_PPPLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_InterestBearingDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bdsx_CARESActMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=bdsx_NotesPayable2018NotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesGPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-Term Debt - Additional Information (Details) - USD ($)	1 Months Ended		9 Months Ended
	Apr. 30, 2020	Feb. 28, 2018	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Facility fee amount			$ 238,000	$ 170,000
PPP Loan
Debt Instrument [Line Items]
Loan description			The PPP Loan matures on the two-year anniversary of the funding date and bears interest at a fixed rate of 1.00% per annum. Monthly principal and interest payments, less the amount of any potential forgiveness (as discussed below), will commence after the ten-month anniversary of the funding date. The Company did not provide any collateral or guarantees in connection with the PPP Loan, nor did the Company pay any facility charge to obtain the PPP Loan.
PPP Loan \| Interest-bearing Deposits
Debt Instrument [Line Items]
Interest rate	1.00%
PPP Loan \| CARES Act
Debt Instrument [Line Items]
Loan principle amount	$ 3,100,000
Percentage for non-payroll costs	40.00%
Upper limit of employee salary to reduce forgiveness	$ 100,000
Percentage of upper limit of employee salary to reduce forgiveness	25.00%
PPP Loan \| CARES Act \| Minimum
Debt Instrument [Line Items]
Payroll costs excludes compensation of an employee	$ 100,000
2018 Notes
Debt Instrument [Line Items]
Loan principle amount		$ 23,000,000	$ 24,543,000	24,088,000
Interest rate		10.00%
Maturity date, description			Feb. 28, 2023
Percentage of facility fee		1.00%
Facility fee amount		$ 200,000
Fair value of warrants issued		$ 300,000
Percentage of interest rate, paid in cash		7.50%
Percentage of interest rate added to principal value of notes payable		2.50%
Frequency of periodic payment			The Company is required to make quarterly interest payments beginning in June 2018 and outstanding principal is due in 24 equal installments commencing in March 2021
Interest added to principal value			$ 1,500,000	$ 1,100,000
Debt instrument, prepayment penalty		3.00%
Debt instrument, back-end facility fee		2.00%
Debt instrument, additional interest expense fee		2.00%
Debt instrument, default amount			$ 0
2018 Notes \| Series G Convertible Preferred Stock
Debt Instrument [Line Items]
Warrant issued to purchase shares		613,333
Exercise price		$ 0.75
2018 Notes \| Minimum
Debt Instrument [Line Items]
Early amortization of loan payment schedule		24 months
2018 Notes \| Maximum
Debt Instrument [Line Items]
Early amortization of loan payment schedule		36 months