23. Related Parties - Compensation (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Parties
Short-term employee benefits	€ 2,598	€ 2,683	€ 1,538
Share-based payments	1,738	1,229	1,379
Termination benefits	264	0	0
Key management personnel compensation	€ 4,600	€ 3,912	€ 2,917

No definition available.

Name:	ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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
-Paragraph 17
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2019-en-r&anchor=para_17&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_KeyManagementPersonnelCompensation
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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
-IssueDate 2019-01-01
-Paragraph 17
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2019-en-r&anchor=para_17_e&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_KeyManagementPersonnelCompensationSharebasedPayment
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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
-Name IAS
-Number 24
-IssueDate 2019-01-01
-Paragraph 17
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2019-en-r&anchor=para_17_a&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_KeyManagementPersonnelCompensationShorttermEmployeeBenefits
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of compensation to key management personnel in the form of termination benefits. [Refer: Termination benefits expense; 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
-Paragraph 17
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2019-en-r&anchor=para_17_d&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_KeyManagementPersonnelCompensationTerminationBenefits
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration