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Pensions and Other Post-employment Benefit Obligations - Additional Information (Detail) - EUR (€) € in Millions | 1 Months Ended | 12 Months Ended
--- | --- | ---
Jan. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Disclosure of defined benefit plans [line items] |  |  |  |
Increase / decrease in the discount rates |  |  | 0.50% |
Weighted-average maturity of defined benefit obligations |  |  | 14 years | 13 years 2 months 12 days
Pensions [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Expected contributions to pension and other benefits |  | € 25 |  |
Other benefits [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Expected contributions to pension and other benefits |  | € 18 |  |
Switzerland [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Decrease in defined benefit obligation resulting from negative past service cost | € (12) |  |  |
United States [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Decrease in defined benefit obligation resulting from negative past service cost |  |  | € (8) |

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- Definition Weighted-average maturity of defined benefit obligations. + References No definition available. + Details
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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The estimate of the expected contributions to be made to a defined benefit plan for the next annual reporting period. [Refer: Defined benefit plans [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 147 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_147_b&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 148 -Subparagraph d -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_148_d_iii&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The increase (decrease) in the net defined benefit liability (asset) resulting from past service cost. Past service cost is the change in the present value of the defined benefit obligation for employee service in prior periods, resulting from a plan amendment (the introduction or withdrawal of, or changes to, a defined benefit plan) or a curtailment (a significant reduction by the entity in the number of employees covered by a plan). [Refer: Net defined benefit liability (asset); Defined benefit plans [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 141 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_d&doctype=Standard -URIDate 2017-03-09 + Details
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- Details
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- Details
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