INVESTMENTS AND OTHER FINANCIAL ASSETS - Narrative (Details) - EUR (€) € in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disclosure of information about unconsolidated subsidiaries [line items]
Other securities and financial assets	€ 8,704	€ 6,162
Liberty Media
Disclosure of information about unconsolidated subsidiaries [line items]
Other securities and financial assets	€ 7,674	€ 5,142

The amount of financial assets that the entity does not separately disclose in the same statement or note. [Refer: Financial assets]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 54
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_54_d&doctype=Standard
-URIDate 2019-03-27

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