Related party transactions - Key Management (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related party transactions
Fixed compensation	€ 782	€ 781	€ 778
Compensation from stock option plan	353	360	231
Total	€ 1,135	€ 1,141	€ 1,009

No definition available.

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- Definition

The amount of compensation to key management personnel. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2019-01-01
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+ Details

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- Definition

The amount of compensation to key management personnel in the form of share-based payments. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
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+ Details

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- Definition

The amount of compensation to key management personnel in the form of short-term employee benefits. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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