Acquisitions, investments, purchases of intangible assets and divestitures - Proceeds from divestitures (Details) - EUR (€)	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Acquisitions, investments, purchases of intangible assets and divestitures
Cash portion of proceeds from divestitures	€ 1,662,458,000	€ 9,634,000

The portion of consideration paid or received, consisting of cash and cash equivalents, in respect of both obtaining and losing control of subsidiaries or other businesses. [Refer: Subsidiaries [member]; Cash and cash equivalents; Consideration paid (received)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2017-01-01
-Paragraph 40
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_40_b&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_PortionOfConsiderationPaidReceivedConsistingOfCashAndCashEquivalents
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration