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.

No definition available.

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount recognised as of the acquisition date for identifiable intangible assets acquired in a business combination. [Refer: Intangible assets other than goodwill; Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 3
-IssueDate 2023-01-01
-Paragraph B64
-Subparagraph i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2023-en-r&anchor=para_B64_i&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 3
-IssueDate 2023-01-01
-Paragraph IE72
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2023-en-r&anchor=para_IE72&doctype=Illustrative%20Examples
-URIDate 2023-03-23

+ Details

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

- Definition

The amount of impairment loss recognised in profit or loss for intangible assets other than goodwill. [Refer: Impairment loss recognised in profit or loss; Intangible assets other than goodwill]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-Clause iv
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e_iv&doctype=Standard
-URIDate 2023-03-23

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Additions other than through business combinations related to companies held-for-sale, intangible assets other than goodwill

+ References

No definition available.

+ Details

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Namespace Prefix:	tef_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Data Type:	na
Balance Type:
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- Details

Name:	ifrs-full_BusinessCombinationsAxis=tef_BETernaGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfIntangibleAssetsOtherThanGoodwillAxis=ifrs-full_LicencesAndFranchisesMember
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Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Data Type:	na
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Data Type:	na
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- Details

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Data Type:	na
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- Details

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Data Type:	na
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Intangible Assets - Narrative (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Apr. 20, 2022
Disclosure of detailed information about intangible assets [line items]
Impairment loss recognised in profit or loss, intangible assets other than goodwill	€ 2	€ 31
Oi Group
Disclosure of detailed information about intangible assets [line items]
Intangible assets			€ 539
Incremental Group
Disclosure of detailed information about intangible assets [line items]
Intangible assets			24
BE-terna Group
Disclosure of detailed information about intangible assets [line items]
Intangible assets			€ 77
Service concession arrangements and licenses
Disclosure of detailed information about intangible assets [line items]
Additions	183	173
Impairment loss recognised in profit or loss, intangible assets other than goodwill	0	19
Service concession arrangements and licenses \| Telefónica Hispam
Disclosure of detailed information about intangible assets [line items]
Additions		125
Service concession arrangements and licenses \| Telefónica Hispam \| Argentina
Disclosure of detailed information about intangible assets [line items]
Additions	109
Service concession arrangements and licenses \| Telefónica Hispam \| Ecuador
Disclosure of detailed information about intangible assets [line items]
Additions	18
Service concession arrangements and licenses \| Telefónica Hispam \| Uruguay
Disclosure of detailed information about intangible assets [line items]
Additions	€ 24
Service concession arrangements and licenses \| Telefónica Brazil
Disclosure of detailed information about intangible assets [line items]
Additions		35
Licences and computer software
Disclosure of detailed information about intangible assets [line items]
Impairment loss recognised in profit or loss, intangible assets other than goodwill		€ 21