Notes on the Consolidated Statements of Operations and Comprehensive Loss - Deferred tax assets and liabilities were recognized (Details) - EUR (€) € in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Income Statement [Abstract]
Net deferred tax assets	€ 15,767	€ 10,482
Net deferred tax liabilities	€ 3,054	€ 1,132

The amount of deferred tax liabilities net of deferred tax assets, when the absolute amount of deferred tax liabilities is greater than the absolute amount of deferred tax assets. [Refer: Deferred tax assets; Deferred tax liabilities]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 12
-IssueDate 2019-01-01
-Paragraph 81
-Subparagraph g
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_g_i&doctype=Standard
-URIDate 2019-03-27

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