Name:	dbvt_NumberOfPatientsIncreasedEdFromBaseline
Namespace Prefix:	dbvt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of patients observed for safety profile till date.

+ References

No definition available.

+ Details

Name:	dbvt_NumberOfPatientsObservedForSafetyProfileTillDate
Namespace Prefix:	dbvt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of patients increased ED from baseline.

+ References

No definition available.

+ Details

Name:	dbvt_PercentageOfPatientsIncreasedEdFromBaseline
Namespace Prefix:	dbvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of patients increased ED of minimum thousand milligram peanut protein by three year.

+ References

No definition available.

+ Details

Name:	dbvt_PercentageOfPatientsIncreasedEdOfMinimumThousandMilligramPeanutProteinByThreeYear
Namespace Prefix:	dbvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Treatment compliance percentage.

+ References

No definition available.

+ Details

Name:	dbvt_TreatmentCompliancePercentage
Namespace Prefix:	dbvt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

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

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesIssuedForServices
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ 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(29))
-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 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

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(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644

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(29))
-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 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187143-122770

+ Details

Name:	us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=dbvt_PublicOfferingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_StatementGeographicalAxis=dbvt_OutsideEuropeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=dbvt_GlobalOfferingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=dbvt_ViaskintmClinicalProgramForChildrenAgedBetweenFourToElevenMember
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:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Significant Events and Transactions - Additional Information (Detail) $ / shares in Units, $ in Thousands				3 Months Ended				9 Months Ended
	Mar. 02, 2020 $ / shares shares	Feb. 04, 2020 $ / shares shares	Jan. 31, 2020 patients	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2021 USD ($) patients shares	Feb. 04, 2020 € / shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio		1.0999
Proceeds From Issuance Of Common Stock \| $								$ 150,000
Stock issued during the period, Value \| $				$ 473	$ 42	$ (472)	$ 151,023
Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues								7,838,687
Public Offering [member] \| Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues		7,500,000						4,874,268
Public Offering [member] \| American Depositary Shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues								9,748,536
Public Offering [member] \| Outside Europe [Member] \| Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues		4,535,581
Public Offering [member] \| Outside Europe [Member] \| American Depositary Shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues		9,071,162
Shares Issued, Price Per Share \| $ / shares		$ 10.25
Over-Allotment Option \| Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues	338,687
Over-Allotment Option \| American Depositary Shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues	677,374
Shares Issued, Price Per Share \| $ / shares	$ 10.25
Global Offering [member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock issued during the period, Value \| $								$ 160,700
Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares Issued, Price Per Share \| € / shares									€ 18.63
Stock Issued During Period, Shares, Issued for Services		2,964,419
ViaskinTM Clinical Program For Children Aged Between Four to Eleven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage Of Patients Increased ED From Baseline			75.90%
Number Of Patients Increased ED From Baseline \| patients								107
Number Of Patients \| patients								141
Percentage Of Patients Increased ED Of Minimum Thousand Milligram Peanut Protein By Three Year			51.80%					73.00%
Number Of Patients Observed For Safety Profile Till Date \| patients			1,000
Treatment Compliance Percentage			98.00%
Clinical Program Trial Period			6 months
Minimum \| ViaskinTM Clinical Program For Children Aged Between Four to Eleven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Age Of Child			4 years
Maximum \| ViaskinTM Clinical Program For Children Aged Between Four to Eleven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Age Of Child			11 years