Note 38 - Dividend income (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividens Revenue Line Items
Dividend income	€ 334	€ 467	€ 415
Financial assets at fair value through profit or loss classified as held for trading [Member]
Dividens Revenue Line Items
Dividend income	145	156	144
Available for sale financial assets [Member]
Dividens Revenue Line Items
Dividend income	188	307	271
Other Assets [Member]
Dividens Revenue Line Items
Dividend income	€ 0	€ 5	€ 0

The amount of dividends recognised as income. Dividends are distributions of profits to holders of equity investments in proportion to their holdings of a particular class of capital.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2018-01-01
-Name IAS
-Number 18
-IssueDate 2016-01-13
-Paragraph 35
-Subparagraph b
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=18&date=2016-03-30&anchor=para_35_b_v&doctype=Standard
-URIDate 2016-03-31

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2016-01-13
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_112_c&doctype=Standard
-URIDate 2016-03-31

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration