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OPERATING SEGMENT INFORMATION - Segment Revenue (Details) - EUR (€) € in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Disclosure of operating segments [line items] |  |  |  |
Revenue | € 1,518 | € 1,031 | € 2,859 | € 2,468
P&ARP |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 904 | 564 | 1,668 | 1,313
A&T |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 274 | 247 | 508 | 596
AS&I |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 340 | 220 | 683 | 559
Segment revenue |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 1,539 | 1,037 | 2,900 | 2,490
Segment revenue | P&ARP |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 907 | 565 | 1,673 | 1,317
Segment revenue | A&T |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 287 | 250 | 532 | 609
Segment revenue | AS&I |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | 345 | 222 | 695 | 564
Inter-segment elimination |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | (21) | (6) | (41) | (22)
Inter-segment elimination | P&ARP |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | (3) | (1) | (5) | (4)
Inter-segment elimination | A&T |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | (13) | (3) | (24) | (13)
Inter-segment elimination | AS&I |  |  |  |
Disclosure of operating segments [line items] |  |  |  |
Revenue | € (5) | € (2) | € (12) | € (5)

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- Definition The amount of revenue from contracts with customers. A customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 15 -IssueDate 2020-01-01 -Paragraph 113 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2020-en-r&anchor=para_113_a&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 15 -IssueDate 2020-01-01 -Paragraph 114 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2020-en-r&anchor=para_114&doctype=Standard -URIDate 2020-01-01 + Details
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