Pensions and other post-employment benefits - Net balance (Details) - EUR (€) € in Millions	Dec. 31, 2017	Dec. 31, 2016
Net defined benefit
Net defined benefit balance	€ (461)	€ (1,198)
United States Pension benefits
Net defined benefit
Net defined benefit balance	2,418	2,252
United States Post-retirement benefits
Net defined benefit
Net defined benefit balance	(1,986)	(2,482)
Other pensions
Net defined benefit
Net defined benefit balance	€ (893)	€ (968)

The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 140
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_140_a&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_LiabilityAssetOfDefinedBenefitPlans
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant