This represents cliff vesting period.

No definition available.

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	glpg_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Other Equity Instruments, vesting period

+ References

No definition available.

+ Details

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

- Definition

Represents the percentage restricted stock unit vesting each year.

+ References

No definition available.

+ Details

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

- Definition

Represents Three year Cliff Vesting Percentage.

+ References

No definition available.

+ Details

Name:	glpg_ThreeYearCliffVestingPercentage.
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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 2
-IssueDate 2025-01-01
-Paragraph 45
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_45&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2025-01-01
-Paragraph 47
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2025-03-27

+ Details

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

- Details

Name:	ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=glpg_ShareBasedPaymentArrangementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=glpg_SubscriptionRightsPlan2025BoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=glpg_SubscriptionRightsPlan2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Events after balance sheet date (Details)							12 Months Ended
Events after balance sheet date (Details)	Mar. 16, 2026 shares	Mar. 06, 2026 shares	Jan. 20, 2026 shares	Nov. 19, 2025 shares	Aug. 07, 2025 shares	May 27, 2025 shares	Dec. 31, 2025 EquityInstruments	Dec. 31, 2024 EquityInstruments	Dec. 31, 2023 EquityInstruments
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement				420,000	905,000	925,000	2,250,000	1,381,000	1,538,400
Share based payment arrangements [member] \| Subscription rights plan 2025 (B) [member]
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement	115,000	127,400	110,000
Share based payment arrangements [member] \| Subscription rights plan 2026 [member]
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement		914,200
Subscription rights created		1,750,000
Share based payment arrangements [member] \| Subscription rights plan 2026 [member] \| Executive committee
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement		586,900
Share based payment arrangements [member] \| RSU Plan 2025.VI, RSU Plan 2026.I, RSU Plan 2026.II [member]
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement		244,700
Share based payment arrangements [member] \| RSU Plan 2025.VI, RSU Plan 2026.I, RSU Plan 2026.II [member] \| Executive committee
Disclosure of non-adjusting events after reporting period
vesting period of RSU		4 years
Percentage Of RSU Vesting Each Year.		25.00%
Share based payment arrangements [member] \| PSU Plan 2026.I [member]
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement		181,600
Cliff Vesting Period		3 years
Three year Cliff Vesting Percentage.		100.00%
Share based payment arrangements [member] \| All RSU and PSU Plans [member] \| Executive committee
Disclosure of non-adjusting events after reporting period
Number of other equity instruments granted in share-based payment arrangement		117,400