XML 215 R133.htm IDEA: XBRL DOCUMENT
v3.26.1

Grupo Santander - Schedule of list of offshore territories (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2025 branch subsidiary | Dec. 31, 2024 branch subsidiary
Guernsey |  |
Disclosure of detailed information about business combination [line items] |  |
Number of subsidiaries tax resident in the UK | subsidiary | 1 |
Off-shore entities |  |
Disclosure of detailed information about business combination [line items] |  |
Number of subsidiaries resident in off-shore territories | subsidiary | 0 | 0
Number of branches resident in off-shore territories | branch | 3 | 3
Off-shore entities | Spanish legislation |  |
Disclosure of detailed information about business combination [line items] |  |
Number of subsidiaries resident in off-shore territories | subsidiary | 0 |
Number of branches resident in off-shore territories | branch | 3 |
Off-shore entities | Council of the EU blacklist |  |
Disclosure of detailed information about business combination [line items] |  |
Number of subsidiaries resident in off-shore territories | subsidiary | 0 |
Number of branches resident in off-shore territories | branch | 0 |
Off-shore entities | OECD |  |
Disclosure of detailed information about business combination [line items] |  |
Number of subsidiaries resident in off-shore territories | subsidiary | 0 |
Number of branches resident in off-shore territories | branch | 0 |
Off-shore entities | Jersey, The Isle of Man And The Cayman Islands | Spanish legislation |  |
Disclosure of detailed information about business combination [line items] |  |
Number of branches resident in off-shore territories | branch | 3 |

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfBusinessCombinationsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of branches. + References No definition available. + Details
Name: | san_NumberOfBranchesResidentInOffShoreTerritories
Namespace Prefix: | san_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of subsidiaries resident in off-shore territories. + References No definition available. + Details
Name: | san_NumberOfSubsidiariesResidentInOffShoreTerritories
Namespace Prefix: | san_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of subsidiaries tax resident in UK. + References No definition available. + Details
Name: | san_NumberOfSubsidiariesTaxResidentInTheUK
Namespace Prefix: | san_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_GG
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=san_OffShoreEntitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | san_TerritorialJurisdictionAxis=san_SpanishLegislationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | san_TerritorialJurisdictionAxis=san_CouncilOfTheEUBlacklistMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | san_TerritorialJurisdictionAxis=san_OECDMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=san_JerseyTheIsleOfManAndTheCaymanIslandsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |