The exercise price of other equity instruments granted.

No definition available.

Name:	glpg_ExercisePriceOtherEquityInstrumentsGranted
Namespace Prefix:	glpg_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average estimated volatility of the share price used to calculate the fair value of the other equity instruments granted.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

The weighted average expected life of other equity instruments granted in years.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

The implied weighted average yield currently available on zero-coupon government issues of the country in whose currency the exercise price for other equity instruments granted is expressed, with a remaining term equal to the expected term of the instruments being valued.

+ References

No definition available.

+ Details

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Namespace Prefix:	glpg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average share price of other equity instruments granted at acceptance date.

+ References

No definition available.

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The amount of expense arising from share-based payment transactions in which the goods or services received did not qualify for recognition as assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 51
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_51_a&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

- Definition

The weighted average fair value at the measurement date of granted equity instruments other than share options. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 47
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2019-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2019-03-27

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Warrant plans - Valuation (Details) - EUR (€)	12 Months Ended
Warrant plans - Valuation (Details) - EUR (€)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Warrant Plans
Share based compensation expense	€ 38,297,000	€ 26,757,000	€ 16,536,000
2019 allocated on April 2019
Warrant Plans
Exercise Price	€ 95.11
Weighted average share price at acceptance date	€ 107.05
Weighted average fair value on the acceptance date	€ 40.04
Weighted average estimated volatility	35.86%
Weighted average expected life of the warrant (years)	6 years
Weighted average risk free rate (%)	(0.27%)
2019 RMV allocated on April 2019
Warrant Plans
Exercise Price	€ 95.11
Weighted average share price at acceptance date	€ 107.45
Weighted average fair value on the acceptance date	€ 40.05
Weighted average estimated volatility	35.63%
Weighted average expected life of the warrant (years)	6 years
Weighted average risk free rate (%)	(0.28%)
2018 allocated on April 2018
Warrant Plans
Exercise Price	€ 79.88
Weighted average share price at acceptance date	€ 84.88
Weighted average fair value on the acceptance date	€ 38.39
Weighted average estimated volatility	39.44%
Weighted average expected life of the warrant (years)	8 years
Weighted average risk free rate (%)	0.51%
2018 RMV allocated on April 2018
Warrant Plans
Exercise Price	€ 79.88
Weighted average share price at acceptance date	€ 84.88
Weighted average fair value on the acceptance date	€ 38.39
Weighted average estimated volatility	39.44%
Weighted average expected life of the warrant (years)	8 years
Weighted average risk free rate (%)	0.51%
2017 allocated on May 2017
Warrant Plans
Exercise Price	€ 80.57
Weighted average share price at acceptance date	€ 68.67
Weighted average fair value on the acceptance date	€ 26.86
Weighted average estimated volatility	40.06%
Weighted average expected life of the warrant (years)	8 years
Weighted average risk free rate (%)	0.33%
2017 RMV allocated on May 2017
Warrant Plans
Exercise Price	€ 80.57
Weighted average share price at acceptance date	€ 68.67
Weighted average fair value on the acceptance date	€ 26.80
Weighted average estimated volatility	40.08%
Weighted average expected life of the warrant (years)	8 years
Weighted average risk free rate (%)	0.29%