Provisions - Schedule of provision for employee commitments (Details) - EUR (€) € in Thousands	Dec. 31, 2024	Dec. 31, 2023
Provisions [abstract]
Employer contribution costs on share-based compensation plans	€ 81	€ 1,684
Phantom shares	1	1,421
Retirement termination benefits	515	459
Leaving indemnities and restructurings	964	670
BALANCE AS AT CLOSING DATE	1,561	4,234
Less non-current portion	546	490
CURRENT PORTION	€ 1,015	€ 3,744

The amount of current provisions for employee benefits. [Refer: Provisions for employee benefits]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 78
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_78_d&doctype=Standard
-URIDate 2024-03-27

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of non-current provisions for employee benefits. [Refer: Provisions for employee benefits]

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

The amount of provisions for employee benefits. [Refer: Employee benefits expense; Provisions]

+ References

+ Details

Name:	ifrs-full_ProvisionsForEmployeeBenefits
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The element represents provision for employee commitments phantom shares.

+ References

No definition available.

+ Details

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Namespace Prefix:	valn_
Data Type:	xbrli:monetaryItemType
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- Definition

Employer contribution costs on share-based compensation plans

+ References

No definition available.

+ Details

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Namespace Prefix:	valn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

The element represents provision for employee commitments leaving indemnities.

+ References

No definition available.

+ Details

Name:	valn_ProvisionsForLeavingIndemnitiesAndRestructurings
Namespace Prefix:	valn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The element represents provision for employee commitments retirement termination benefits.

+ References

No definition available.

+ Details

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Namespace Prefix:	valn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant