v3.20.1

Auditor's remuneration (Details) - EUR (€) | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Auditor's remuneration |  |
Statutory auditor's fees | € 1,406,800 | € 414,600
Fees for audit-related services | 29,200 | 0
Fees for persons related to the statutory auditor | 29,200 | 27,500
Fees for legal assignments | 43,000 | 92,100
Other fees related to non-audit services executed by the statutory auditor | 148,200 |
Other fees related to non-audit services executed by persons related to the statutory auditor | € 46,600 |
Other fees related to IT services |  | € 134,800

X
- Definition The amount of fees paid or payable to the entity's auditors for legal assignments. + References No definition available. + Details
Name: | glpg_AuditorSRemunerationForLegalAssignments
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of fees paid or payable to the person related to auditor for statutory auditing services. + References No definition available. + Details
Name: | glpg_FeesForPersonsRelatedToStatutoryAuditor
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other fees related to IT services. + References No definition available. + Details
Name: | glpg_OtherFeesRelatedToInformationTechnologyServices.
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other fees related to non-audit fees executed by statutory auditor. + References No definition available. + Details
Name: | glpg_OtherFeesRelatedToNonAuditServicesExecutedByPersonsRelatedToStatutoryAuditor.
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other fees related to non-audit fees executed by statutory auditor. + References No definition available. + Details
Name: | glpg_OtherFeesRelatedToNonAuditServicesExecutedByStatutoryAuditor.
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | ifrs-full_AuditorsRemunerationAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of fees paid or payable to the entity's auditors for auditing services. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_AuditorsRemunerationForAuditServices
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of fees paid or payable to the entity's auditors for services that the entity does not separately disclose in the same statement or note. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_AuditorsRemunerationForOtherServices
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration