v3.20.1

Operating costs - Summary of research and development expenditure (Details) - EUR (€) € in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Operating costs |  |  |
Personnel costs | € (124,260) | € (81,352) | € (59,950)
Subcontracting | (249,926) | (197,644) | (123,054)
Disposables and lab fees and premise costs | (23,880) | (25,525) | (22,277)
Depreciation | (10,874) | (5,655) | (3,679)
Other operating expenses | (18,380) | (12,699) | (9,542)
Total R&D expenses | € (427,320) | € (322,875) | € (218,502)

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

X
- Definition Amount of research and development disposables and lab fees and premises costs. + References No definition available. + Details
Name: | glpg_ResearchAndDevelopmentDisposablesAndLabFeesAndPremisesCosts
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Amount of research and development personnel costs. + References No definition available. + Details
Name: | glpg_ResearchAndDevelopmentPersonnelCosts
Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of research and development subcontracting costs. + References No definition available. + Details
Name: | glpg_ResearchAndDevelopmentSubcontracting
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 expenditure directly attributable to research or development activities, recognised in profit or loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 38 -IssueDate 2019-01-01 -Paragraph 126 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=38&code=ifrs-tx-2019-en-r&anchor=para_126&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_ResearchAndDevelopmentExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration