Name:	ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of share options exercised in a share-based payment arrangement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2025-01-01
-Paragraph 45
-Subparagraph b
-Clause iv
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_45_b_iv&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 31
-Subparagraph b
-Clause iv
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_31_b_iv&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 31
-Subparagraph b
-Clause iv
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_31_b_iv&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_NumberOfShareOptionsExercisedInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

The number of share options granted in a share-based payment arrangement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2025-01-01
-Paragraph 45
-Subparagraph b
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_45_b_ii&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 31
-Subparagraph b
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_31_b_ii&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 31
-Subparagraph b
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_31_b_ii&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_NumberOfShareOptionsGrantedInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

Share-Based Payment Arrangements, Expiration Period

No definition available.

Name:	valn_ShareBasedPaymentArrangementsExpirationPeriod
Namespace Prefix:	valn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Share-Based Payment Arrangements, Number Of Equal Tranches To Exercise Awards

No definition available.

Name:	valn_ShareBasedPaymentArrangementsNumberOfEqualTranchesToExerciseAwards
Namespace Prefix:	valn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Share-Based Payment Arrangements, Number Of Successive Plans

No definition available.

Name:	valn_ShareBasedPaymentArrangementsNumberOfSuccessivePlans
Namespace Prefix:	valn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The element represents percentageof voting rights.

No definition available.

Name:	valn_ShareBasedPaymentArrangementsVestingDueToTakeoverMinimumPercentage
Namespace Prefix:	valn_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

Share-Based Payment Arrangements, Vesting Period

No definition available.

Name:	valn_ShareBasedPaymentArrangementsVestingPeriod
Namespace Prefix:	valn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Weighted Average Fair Value Price At Measurement Date, Share Options Granted

No definition available.

Name:	valn_WeightedAverageFairValuePriceAtMeasurementDateShareOptionsGranted
Namespace Prefix:	valn_
Data Type:	dtr-types1:perShareItemType
Balance Type:	na
Period Type:	duration

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=valn_StockOptionPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsPlanAxis=valn_ESOPPlans2013To2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsTrancheAxis=valn_TrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsTrancheAxis=valn_TrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsPlanAxis=valn_ESOPPlan2019OnwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsTrancheAxis=valn_TrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsPlanAxis=valn_ESOP2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsPlanAxis=valn_ESOP2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	valn_ShareBasedPaymentArrangementsPlanAxis=valn_ESOP2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: