v3.20.1

Income Taxes - Schedule of tax liabilities (Details) € in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 EUR (€) subsidiary | Dec. 31, 2018 EUR (€) subsidiary | Dec. 31, 2017 EUR (€)
Income Taxes |  |  |
Current tax payable | € 2,037 | € 1,175 | € 865
Total tax liabilities | € 2,037 | € 1,175 | € 865
Number of subsidiaries operating on a cost plus basis | subsidiary | 4 | 5 |

X
- Definition The amount of tax liabilities. + References No definition available. + Details
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Namespace Prefix: | glpg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the number of subsidiaries operating on a cost plus basis. + References No definition available. + Details
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Namespace Prefix: | glpg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of current tax for current and prior periods to the extent unpaid. Current tax is the amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 54 -Subparagraph n -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_54_n&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_CurrentTaxLiabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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