Post-employment benefits - Sensitivity of key assumptions (Detail) - EUR (€) € in Millions	Dec. 31, 2017	Dec. 31, 2016
Discount rate (1% movement) [Member]
Sensitivity analysis for actuarial assumptions [Line items]
Increase	€ (323)	€ (544)
Decrease	394	645
Inflation rate (1% movement) [Member]
Sensitivity analysis for actuarial assumptions [Line items]
Increase	85	139
Decrease	(86)	(126)
Salary increase (1% movement) [Member]
Sensitivity analysis for actuarial assumptions [Line items]
Increase	20	27
Decrease	(19)	(23)
Longevity (1% movement) [Member]
Sensitivity analysis for actuarial assumptions [Line items]
Increase	€ 72	€ 143

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.

No definition available.

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- Definition

The increase (decrease) in a defined benefit obligation that would have been caused by a decrease in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 145
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-URIDate 2017-03-09

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The increase (decrease) in a defined benefit obligation that would have been caused by an increase in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [member]]

+ References

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