Nota 17 - Intangible assets. Other intangible assets (Details) - EUR (€) € in Millions	Jun. 30, 2018	Dec. 31, 2017
Intangible Assets Other Than Goodwill Line Items
Other intangible assets	€ 2,225	€ 2,402
Computer Software Acquisiton Expenses [Member]
Intangible Assets Other Than Goodwill Line Items
Other intangible assets	1,613	1,682
Intangible Assets With Indefinite Useful Life Member
Intangible Assets Other Than Goodwill Line Items
Other intangible assets	12	12
Intangible Assets With definite Useful Life [Member]
Intangible Assets Other Than Goodwill Line Items
Other intangible assets	€ 600	€ 708

The amount of identifiable non-monetary assets without physical substance. This amount does not include goodwill. [Refer: Goodwill]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2017-01-01
-Paragraph 118
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=38&date=2017-03-01&anchor=para_118_e&doctype=Standard
-URIDate 2017-03-09

Reference 2: 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

Name:	ifrs-full_IntangibleAssetsOtherThanGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant