v3.20.1

Current financial investments (Details) - 12 months ended Dec. 31, 2019 € in Thousands, $ in Millions	USD ($)	EUR (€)
Current financial investments
Current financial investments | €		€ 3,919,216
Short term bond fund minimum investment period	6 months
Current financial investments held in USD | $	$ 850.5

X

- Definition

Current Financial Investments [Abstract]

+ References

No definition available.

+ Details

Name:	glpg_CurrentFinancialInvestmentsAbstract
Namespace Prefix:	glpg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The carrying balance of current financial investments subject to foreign currency exchange gain or loss in our financial results.

+ References

No definition available.

+ Details

Name:	glpg_CurrentFinancialInvestmentsSubjectToForeignCurrencyExchangeGainOrLoss
Namespace Prefix:	glpg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Represents the short term bond fund minimum recommended investment period.

+ References

No definition available.

+ Details

Name:	glpg_ShortTermBondFundMinimumInvestmentPeriod
Namespace Prefix:	glpg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of current investments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_55&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_CurrentInvestments
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant