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OPERATING SEGMENT INFORMATION - Segment Capital Expenditures (Details) - EUR (€) € in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of operating segments [line items] |  |  |
Capital expenditures | € (182) | € (271) | € (277)
P&ARP |  |  |
Disclosure of operating segments [line items] |  |  |
Capital expenditures | (73) | (96) | (97)
A&T |  |  |
Disclosure of operating segments [line items] |  |  |
Capital expenditures | (45) | (72) | (70)
AS&I |  |  |
Disclosure of operating segments [line items] |  |  |
Capital expenditures | (61) | (97) | (105)
H&C |  |  |
Disclosure of operating segments [line items] |  |  |
Capital expenditures | € (3) | € (6) | € (5)

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