v3.20.1

Operating costs - Summary of general and administrative expenses (Details) - EUR (€) € in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Operating costs |  |  |
Personnel costs and directors fees | € (51,906) | € (25,495) | € (17,756)
Depreciation | (1,513) | (513) | (606)
Legal and professional fees | (11,775) | (4,284) | (2,427)
Other operating expenses | (8,506) | (5,339) | (3,626)
Total general and administrative expenses | € (73,701) | € (35,631) | € (24,415)

X
- Definition The amount of depreciation expense incurred during period, included in general and administrative expenses. + References No definition available. + Details
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Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of legal and professional fees incurred during period, included in general and administrative expenses. + References No definition available. + Details
Name: | glpg_GeneralAndAdministrativeLegalAndProfessionalFees
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of general and administrative other operating expenses. + References No definition available. + Details
Name: | glpg_GeneralAndAdministrativeOtherOperatingExpenses
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of general and administrative personnel costs and director fees. + References No definition available. + Details
Name: | glpg_GeneralAndAdministrativePersonnelCostsAndDirectorFees
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition The amount of expense relating to general and administrative activities of the entity. + 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
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Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration