OTHER LIABILITIES - Narrative (Details) - Maintenance and power warranty programs € in Millions	Dec. 31, 2019 EUR (€)
2020
Disaggregation of Revenue [Line Items]
Expected amounts to be recognized in revenue	€ 61
2021
Disaggregation of Revenue [Line Items]
Expected amounts to be recognized in revenue	44
2022
Disaggregation of Revenue [Line Items]
Expected amounts to be recognized in revenue	35
Afterwards
Disaggregation of Revenue [Line Items]
Expected amounts to be recognized in revenue	€ 79

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 2019-01-01
-Paragraph 120
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2019-en-r&anchor=para_120_a&doctype=Standard
-URIDate 2019-03-27

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