Name:	glpg_IfrsShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod
Namespace Prefix:	glpg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The percentage of other equity instruments vested for share based payment transaction.

No definition available.

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

The weighted average remaining contractual life of outstanding of other equity instruments.

No definition available.

Name:	glpg_WeightedAverageRemainingContractualLifeOutstandingOfOtherEquityInstruments
Namespace Prefix:	glpg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

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

The amount of expense arising from share-based payment transactions in which the goods or services received did not qualify for recognition as assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2024-01-01
-Paragraph 51
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2024-en-r&anchor=para_51_a&doctype=Standard
-URIDate 2024-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The number of other equity instruments (ie other than share options) granted in a share-based payment arrangement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 2
-IssueDate 2024-01-01
-Paragraph 45
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2024-en-r&anchor=para_45&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2024-01-01
-Paragraph 47
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2024-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2024-03-27

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

The weighted average exercise price of other equity instruments (ie other than share options) outstanding in a share-based payment arrangement. [Refer: Weighted average [member]]

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Namespace Prefix:	ifrs-full_
Data Type:	dtr-2022:perShareItemType
Balance Type:	na
Period Type:	instant

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

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=glpg_SupervisoryBoardMembersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	glpg_IfrsVestingAxis=glpg_IfrsShareBasedCompensationAwardTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	glpg_IfrsVestingAxis=glpg_IfrsShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: