v3.20.1

Significant accounting policies - Segment Reporting (Details) | 12 Months Ended
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Dec. 31, 2019 segment
Significant accounting policies |
Number of reportable segments | 2

X
- Definition The disclosure of significant accounting policies. + References No definition available. + Details
Name: | glpg_DisclosureOfSignificantAccountingPoliciesAbstract
Namespace Prefix: | glpg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | glpg_IfrsNumberOfReportableSegments
Namespace Prefix: | glpg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration