v3.25.1

Discontinued operations and assets held for sale - Transfer of Jyseleca Business to Alfasigma (Details) - Jyseleca business, classified as held for sale				1 Months Ended	12 Months Ended
	Jan. 31, 2024 EUR (€) position country	Dec. 30, 2023 item	Oct. 30, 2023 country	Jan. 31, 2024 EUR (€) item country	Dec. 31, 2024 EUR (€)
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Number of positions in European countries agreed to transfer	400	400		400
Number of European countries in which positions has been agreed to transfer | country	14		14	14
Upfront payment to receive.				€ 50,000,000	€ 50,000,000
Potential Sales Based Milestones To Receive.	€ 120,000,000			€ 120,000,000	120,000,000
Commitments Related To Development Activities.					25,000,000
Contributions related to development activities.					€ 15,000,000
Galapagos Biotech Ltd. (formerly Inpharmatica Ltd.)
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Belgium BV [member]
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Germany GmbH
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Italy S.r.l.
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Netherlands BV [member]
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Spain S.L.U
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma ApS
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma A.B.
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Oy
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos Biopharma Ireland Ltd
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%
Galapagos GmbH
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Proportion Of Ownership Interest In Subsidiary Sold					100.00%

X

- Definition

Commitments to Alfasigma related to development activities.

+ References

No definition available.

+ Details

Name:	glpg_CommitmentsRelatedToDevelopmentActivities.
Namespace Prefix:	glpg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

contributions to Alfasigma related to development activities.

+ References

No definition available.

+ Details

Name:	glpg_ContributionsToRelatedDevelopmentActivities.
Namespace Prefix:	glpg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Number of European countries agreed in which positions has been agreed to transfer, pursuant to an arrangement.

+ References

No definition available.

+ Details

Name:	glpg_NumberOfEuropeanCountriesInWhichPositionsHasBeenAgreedToTransfer
Namespace Prefix:	glpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of positions agreed to transfer, pursuant to an arrangement.

+ References

No definition available.

+ Details

Name:	glpg_NumberOfPositionsAgreedToTransfer
Namespace Prefix:	glpg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The proportion of ownership interest in a subsidiary attributable to the entity that is sold.

+ References

No definition available.

+ Details

Name:	glpg_ProportionOfOwnershipInterestInSubsidiarySold
Namespace Prefix:	glpg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of cash inflow received as upfront payment.

+ References

No definition available.

+ Details

Name:	glpg_UpfrontPaymentReceived
Namespace Prefix:	glpg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of upfront payments receivable.

+ References

No definition available.

+ Details

Name:	glpg_UpfrontPaymentsReceivable
Namespace Prefix:	glpg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

+ Details

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

X

- Details

Name:	ifrs-full_ContinuingAndDiscontinuedOperationsAxis=glpg_JyselecaBusinessClassifiedAsHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiotechLtd.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaBelgiumBvMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaGmbhMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaS.r.lMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaNetherlandsBvMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaS.l.uMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaApsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaA.b.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaOyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosBiopharmaLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=glpg_GalapagosGmbhMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: