Note 15 - Financial assets at fair value through OCI (Detail) - Financial assets at fair value through OCI [Member] - EUR (€) € in Millions	Dec. 31, 2023	Dec. 31, 2022
Financial assets at fair value through OCI [Line Items]
Securities purchased under resale agreement	€ 1,805	€ 2,156
Debt securities [Abstract]:
German government	1,566	602
U.S. Treasury and U.S. government agencies	9,232	12,334
U.S. local (municipal) governments	446	392
Other foreign governments	15,672	9,960
Corporates	686	708
Other asset-backed securities	0	0
Mortgage-backed securities, including obligations of U.S. federal agencies	442	486
Other debt securities	831	969
Total debt securities	28,874	25,450
Loans	4,867	4,069
Total financial assets at fair value through other comprehensive income	€ 35,546	€ 31,675

The amount of financial assets that are measured at fair value through other comprehensive income. A financial asset shall be measured at fair value through other comprehensive income if both of the following conditions are met: (a) the financial asset is held within a business model whose objective is achieved by both collecting contractual cash flows and selling financial assets and (b) the contractual terms of the financial asset give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. [Refer: At fair value [member]; Financial assets]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2023-01-01
-Paragraph 8
-Subparagraph h
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2023-en-r&anchor=para_8_h&doctype=Standard
-URIDate 2023-03-23

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