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Intangible Assets (Including Goodwill) - Disclosure of Changes in Intangible Assets and Goodwill (Detail) - EUR (€) € in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Goodwill, beginning balance | € 457 | € 443
Effects of changes in foreign exchange rates | (54) | 14
Goodwill, ending balance | 403 | 457
Intangible assets (excluding goodwill), beginning balance | 79 | 78
Intangible assets (excluding goodwill), additions | 6 | 5
Intangible assets (excluding goodwill), amortization expense | (12) | (11)
Intangible assets (excluding goodwill), transfer during the period | 2 |
Intangible assets (excluding goodwill), effects of changes in foreign exchange rates | (7) | 7
Intangible assets (excluding goodwill), ending balance | 68 | 79
Gross value [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Goodwill, beginning balance | 457 |
Goodwill, ending balance | 403 | 457
Intangible assets (excluding goodwill), beginning balance | 198 |
Intangible assets (excluding goodwill), ending balance | 186 | 198
Accumulated amortization and impairment [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | (119) |
Intangible assets (excluding goodwill), ending balance | (118) | (119)
Technology [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 28 | 28
Intangible assets (excluding goodwill), amortization expense | (1) | (1)
Intangible assets (excluding goodwill), transfer during the period | 1 |
Intangible assets (excluding goodwill), effects of changes in foreign exchange rates | (4) | 1
Intangible assets (excluding goodwill), ending balance | 24 | 28
Technology [member] | Gross value [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 91 |
Intangible assets (excluding goodwill), ending balance | 81 | 91
Technology [member] | Accumulated amortization and impairment [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | (63) |
Intangible assets (excluding goodwill), ending balance | (57) | (63)
Computer software [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 21 | 23
Intangible assets (excluding goodwill), additions |  | 1
Intangible assets (excluding goodwill), amortization expense | (9) | (9)
Intangible assets (excluding goodwill), transfer during the period | 7 | 2
Intangible assets (excluding goodwill), effects of changes in foreign exchange rates | (1) | 4
Intangible assets (excluding goodwill), ending balance | 18 | 21
Computer software [member] | Gross value [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 52 |
Intangible assets (excluding goodwill), ending balance | 55 | 52
Computer software [member] | Accumulated amortization and impairment [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | (31) |
Intangible assets (excluding goodwill), ending balance | (37) | (31)
Customer relationships [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 18 | 18
Intangible assets (excluding goodwill), amortization expense | (1) | (1)
Intangible assets (excluding goodwill), effects of changes in foreign exchange rates | (2) | 1
Intangible assets (excluding goodwill), ending balance | 15 | 18
Customer relationships [member] | Gross value [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 43 |
Intangible assets (excluding goodwill), ending balance | 38 | 43
Customer relationships [member] | Accumulated amortization and impairment [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | (25) |
Intangible assets (excluding goodwill), ending balance | (23) | (25)
Work in progress [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 9 | 7
Intangible assets (excluding goodwill), additions | 6 | 4
Intangible assets (excluding goodwill), transfer during the period | (6) | (2)
Intangible assets (excluding goodwill), ending balance | 9 | 9
Work in progress [member] | Gross value [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 9 |
Intangible assets (excluding goodwill), ending balance | 9 | 9
Other intangible assets [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 3 | 2
Intangible assets (excluding goodwill), amortization expense | (1) |
Intangible assets (excluding goodwill), effects of changes in foreign exchange rates |  | 1
Intangible assets (excluding goodwill), ending balance | 2 | 3
Other intangible assets [member] | Gross value [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), beginning balance | 3 |
Intangible assets (excluding goodwill), ending balance | 3 | € 3
Other intangible assets [member] | Accumulated amortization and impairment [member] |  |
Disclosure of reconciliation of changes in intangible assets and goodwill [line items] |  |
Intangible assets (excluding goodwill), ending balance | € (1) |

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- Definition The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Business combinations [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 3 -IssueDate 2017-01-01 -Paragraph B67 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2017-03-01&anchor=para_B67_d&doctype=Appendix&seq=2 -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2017-01-01 -Paragraph 134 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_134_a&doctype=Standard -URIDate 2017-03-09 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2017-01-01 -Paragraph 135 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_135_a&doctype=Standard -URIDate 2017-03-09 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 54 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_54_c&doctype=Standard -URIDate 2017-03-09 + Details
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