Revenue - Performance Obligations Satisfied in Previous Years (Details) € in Millions	12 Months Ended
Dec. 31, 2018 EUR (€)
Revenue
Revenue recognized in the reporting period for performance obligations satisfied in earlier periods	€ 132

The amount of revenue from performance obligations satisfied (or partially satisfied) in previous periods. [Refer: Performance obligations [member]; Revenue]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2018-01-01
-Paragraph 116
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=15&date=2018-03-01&anchor=para_116_c&doctype=Standard
-URIDate 2018-03-16

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