Property, plant and equipment - Operating leases (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, plant and equipment
Operating lease commitments	€ 34	€ 38	€ 34
Plant and machinery
Property, plant and equipment
Operating lease commitments	5	5	5
Land and buildings
Property, plant and equipment
Operating lease commitments	19	24	21
Office equipment and vehicles
Property, plant and equipment
Operating lease commitments	€ 10	€ 9	€ 8

The portion of operating lease payments that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with any amounts guaranteed by the lessee or by a party related to the lessee recognised as an expense.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2017-01-01
-Paragraph 35
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2017-03-02&anchor=para_35_c&doctype=Standard&book=B
-URIDate 2017-03-09

Name:	ifrs-full_MinimumOperatingLeasePayments
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration