PROVISIONS - Narrative (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [line items]
Expected provisions settlement period	40 years
Expense of restructuring activities	€ 13	€ 4	€ 1
Close down and environmental remediation costs
Disclosure of other provisions [line items]
Change in discount rate	5.00%
Change in provision	€ 1

The amount of expense relating to restructuring. Restructuring is a programme that is planned and controlled by management and materially changes either the scope of a business undertaken by an entity or the manner in which that business is conducted. Such programmes include: (a) the sale or termination of a line of business; (b) closure of business locations in a country or region or the relocation of activities from one country or region to another; (c) changes in management structure; and (d) fundamental reorganisations that have a material effect on the nature and focus of the entity's operations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 98
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_98_b&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_ExpenseOfRestructuringActivities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration