Debt instrument interest added to principal value.

No definition available.

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

Minimum liquidity ratio covenant.

+ References

No definition available.

+ Details

Name:	bdsx_MinimumLiquidityRatioCovenant
Namespace Prefix:	bdsx_
Data Type:	xbrli:pureItemType
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 minimum revenue requirement.

+ References

No definition available.

+ Details

Name:	bdsx_PercentageOfMinimumRevenueRequirement
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

Revenue milestone.

+ References

No definition available.

+ Details

Name:	bdsx_RevenueMilestone
Namespace Prefix:	bdsx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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, 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

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

+ 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 (g)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentCovenantDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

+ Details

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

- Definition

Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4297-108586

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3367-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3536-108585

+ Details

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

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_TwoThousandTwentyOneTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
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:	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:

Debt - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended
Debt - Additional Information (Details) - USD ($)	Mar. 19, 2021	Apr. 30, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Feb. 28, 2018
Debt Instrument [Line Items]
Estimated air value of warrants issued			$ 300,000
Loss on debt extinguishment			(728,000)
Cash paid for interest			600,000	$ 100,000
2021 Term Loan
Debt Instrument [Line Items]
Notes/Loan payable	$ 30,000,000		$ 30,000,000
Debt instrument frequency of periodic payment	monthly
Revenue milestone	$ 65,000,000
Debt instrument description			The 2021 Term Loan provides for an “interest-only” period from the Effective Date through February 28, 2023, with interest due and payable monthly on the first calendar day of each month, provided however, if the Company achieves a revenue milestone of at least $65 million on a trailing twelve-month basis as of the end of any calendar month ending on or prior to September 30, 2022, the interest-only period shall automatically be extended through February 28, 2024. Beginning on the first calendar day of the month following the end of the interest-only period, the 2021 Term Loan shall be payable in (i) consecutive equal installments of principal through March 1, 2026, plus (ii) monthly payments of accrued interest. The principal amount outstanding under the 2021 Term Loan shall accrue interest at a floating per annum rate equal to the greater of (i) 2.00% above the prime rate, or (ii) 5.25%, which interest, in each case, shall be payable monthly. Changes to the interest rate applicable to the 2021 Loan based on changes to the prime rate shall be effective on the effective date of any change to the prime rate.
Debt instrument maturity date	Mar. 01, 2026
Repayments of Debt	$ 2,400,000
Debt instrument, covenant description			The 2021 Term Loan requires the Company to comply with a minimum liquidity ratio covenant (as defined) by the 2021 Term Loan of not less than 0.95 to 1.00, and has a trailing six month rolling minimum revenue requirement of not less than 70% of the Company’s projected revenue for each such quarter.
Loan principle amount	$ 30,000,000		$ 30,000,000
2021 Term Loan \| Prior to First Anniversary
Debt Instrument [Line Items]
Debt instrument, prepayment penalty	3.00%
2021 Term Loan \| Prior to Second Anniversary
Debt Instrument [Line Items]
Debt instrument, prepayment penalty	2.00%
2021 Term Loan \| After Second Anniversary, Prior to October 19, 2025
Debt Instrument [Line Items]
Debt instrument, prepayment penalty	1.00%
2021 Term Loan \| Thereafter
Debt Instrument [Line Items]
Debt instrument, prepayment penalty	0.00%
2021 Term Loan \| Maximum
Debt Instrument [Line Items]
Minimum liquidity ratio covenant	0.95
Percentage of minimum revenue requirement	70.00%
2018 Notes
Debt Instrument [Line Items]
Notes/Loan payable					$ 24,972,000	$ 23,000,000.0
Repayments of Debt	$ 25,900,000
Facility fee amount						200,000
Estimated air value of warrants issued						$ 300,000
Interest rate						10.00%
Percentage of interest rate, paid in cash						7.50%
Percentage of interest rate added to principal value of notes payable						2.50%
Interest added to principal value					1,700,000
Loss on debt extinguishment			$ 700,000
Loan principle amount					24,972,000	$ 23,000,000.0
2018 Notes \| Series G Preferred Stock
Debt Instrument [Line Items]
Warrant issued to purchase shares			613,333			613,333
PPP Loan
Debt Instrument [Line Items]
Debt instrument description			The PPP Loan matures on the two-year anniversary of the funding date, April 2022, 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 in September 2021. 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]
Notes/Loan payable		$ 3,100,000	$ 3,125,000		3,107,000
Loan principle amount		$ 3,100,000	$ 3,125,000		$ 3,107,000
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 \| Minimum \| CARES Act
Debt Instrument [Line Items]
Payroll costs excludes compensation of an employee		$ 100,000