Other financial assets - Text Details (Detail) - EUR (€) € in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other financial assets [Abstract]
Other current financial assets	€ 2	€ 0	€ 1
Non-current investments in equity instruments designated at fair value through other comprehensive income	€ 273	€ 119

The amount of non-current investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: Investments in equity instruments designated at fair value through other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2021-01-01
-Paragraph 8
-Subparagraph h
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_h&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_NoncurrentInvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant