The amount of additional other provisions made. [Refer: Other provisions]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2024-01-01
-Paragraph 84
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2024-en-r&anchor=para_84_b&doctype=Standard
-URIDate 2024-03-27

+ Details

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

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

- Definition

The losses on settlements of litigation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 98
-Subparagraph f
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_98_f&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_LossesOnLitigationSettlements
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of provisions other than provisions for employee benefits. [Refer: Provisions]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2024-01-01
-Paragraph 84
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2024-en-r&anchor=para_84_a&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 78
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_78_d&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_OtherProvisions
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Guarantees Partially Executed From Tax Litigation

+ References

No definition available.

+ Details

Name:	tef_GuaranteesPartiallyExecutedFromTaxLitigation
Namespace Prefix:	tef_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase Legal Claim In Peru, Tax Litigation, Percentage

+ References

No definition available.

+ Details

Name:	tef_IncreaseLegalClaimTaxLitigationPercentage
Namespace Prefix:	tef_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Years In Processing Lawsuits, Tax Litigation In Peru

+ References

No definition available.

+ Details

Name:	tef_NumberOfYearsInProcessingLawsuitsTaxLitigation
Namespace Prefix:	tef_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Other possible contingent liabilities

+ References

No definition available.

+ Details

Name:	tef_OtherPossibleContingentLiabilities
Namespace Prefix:	tef_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Tax Amortization From Goodwill, Assessment

+ References

No definition available.

+ Details

Name:	tef_TaxAmortizationFromGoodwillAssessment
Namespace Prefix:	tef_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	ifrs-full_ClassesOfProvisionsAxis=ifrs-full_ProvisionForTaxesOtherThanIncomeTaxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=tef_TelefonicaPeruMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=tef_PeruRulingsinJuneandAugust2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=tef_TelefonicaBrazilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=tef_TelefonicaPeruMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	tef_TaxablePeriodAxis=tef_TaxYear2011To2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Tax Matters - Tax Litigation in Telefonica Brazil and Peru Narrative (Details) € in Millions, S/ in Millions, R$ in Millions	6 Months Ended			12 Months Ended
	Jun. 30, 2024 EUR (€)	Jun. 30, 2024 BRL (R$)	Jun. 30, 2024 PEN (S/)	Dec. 31, 2024 EUR (€) yr	Dec. 31, 2024 BRL (R$)	Dec. 31, 2024 PEN (S/)	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 BRL (R$)	Dec. 31, 2023 PEN (S/)	Dec. 31, 2024 BRL (R$) yr	Dec. 31, 2024 PEN (S/) yr	Dec. 31, 2023 BRL (R$)	Dec. 31, 2023 PEN (S/)	Dec. 31, 2022 yr
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Losses on litigation settlements				€ 4,002	R$ 25,760		€ 4,323	R$ 23,130
Other provisions \| €				2,189			2,574
Tax proceedings \| Telefónica Peru
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Additions				132		S/ 517	143		S/ 587
Tax proceedings \| Telefónica Peru \| Peru - Rulings in June and August 2015
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Other provisions				700			761				S/ 2,739		S/ 3,117
Telefónica Brazil
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Other possible contingencies				€ 34			37			R$ 216		R$ 198
Telefónica Peru
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Number of years in processing lawsuits, tax litigation \| yr				20						20	20			20
Increase legal claim, tax litigation, (in percent)														80.00%
Guarantees partially executed from tax litigation	€ 272		S/ 1,105
Tax Year 2011 to 2021 \| Telefónica Brazil
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Other possible contingencies				€ 5,706			€ 5,678			R$ 36,723		R$ 30,379
Tax amortization from goodwill, assessment	€ 624	R$ 4,018