Revenue - Remaining Performance Obligations (Details) - EUR (€) € in Billions	Dec. 31, 2020	Dec. 31, 2019
Revenue
Unsatisfied performance obligations	€ 33.4	€ 33.3

The amount of the transaction price allocated to the performance obligations that are unsatisfied (or partially unsatisfied) as of the end of the reporting period. The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). [Refer: Performance obligations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2020-01-01
-Paragraph 120
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2020-en-r&anchor=para_120_a&doctype=Standard
-URIDate 2020-01-01

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