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Operating Segment Information - Summary of Segment Capital Expenditures (Detail) - EUR (€) € in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Disclosure of operating segments [line items] |  |  |
Segment capital expenditures | € (277) | € (276) | € (355)
P&ARP [member] |  |  |
Disclosure of operating segments [line items] |  |  |
Segment capital expenditures | (97) | (115) | (166)
A&T [member] |  |  |
Disclosure of operating segments [line items] |  |  |
Segment capital expenditures | (70) | (73) | (96)
AS&I [member] |  |  |
Disclosure of operating segments [line items] |  |  |
Segment capital expenditures | (105) | (83) | (84)
Holdings & Corporate [member] |  |  |
Disclosure of operating segments [line items] |  |  |
Segment capital expenditures | € (5) | € (5) | € (9)

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