The amount of outstanding funds that the entity is obligated to repay.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_55&doctype=Standard
-URIDate 2017-03-09

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The current portion of non-current borrowings. [Refer: Borrowings]

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
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- Definition

The amount of assistance by government in the form of transfers of resources to an entity in return for past or future compliance with certain conditions relating to the operating activities of the entity, recognised as deferred income. They exclude those forms of government assistance that cannot reasonably have a value placed upon them and transactions with government that cannot be distinguished from the normal trading transactions of the entity. [Refer: Government [member]]

+ References

+ Details

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

- Definition

The amount of outstanding commitments made by the entity in related party transactions. [Refer: Related parties [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2017-01-01
-Paragraph 18
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=24&date=2017-03-01&anchor=para_18_b&doctype=Standard
-URIDate 2017-03-09

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Conditional Payment Period To Suppliers

+ References

No definition available.

+ Details

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Namespace Prefix:	tef_
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Balance Type:	na
Period Type:	duration

- Definition

Payment On Borrowings

+ References

No definition available.

+ Details

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

- Definition

Pending Payments of Other Current Non-Financial Non-Trade Payables

+ References

No definition available.

+ Details

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

- Definition

[Line Items] for Trade And Other Payables [Table]

+ References

No definition available.

+ Details

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Namespace Prefix:	tef_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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Period Type:

Trade and Other Payables - Narrative (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Trade And Other Payables [Line Items]
Grants	€ 87	€ 110
Borrowings	47,375
Pending payments of other current non-financial non-trade payables	€ 145
Maximum payment period to suppliers	60 days
Licenses
Trade And Other Payables [Line Items]
Payment on borrowings	€ 329	198
Spectrum \| Licenses
Trade And Other Payables [Line Items]
Short-term payables	172	504
Fundación Telefónica
Trade And Other Payables [Line Items]
Outstanding commitments made by entity, related party transactions			€ 325
Telefónica México \| Spectrum \| Licenses
Trade And Other Payables [Line Items]
Borrowings	598	654
Short-term payables	72	73
Telefónica Brazil \| Spectrum \| Licenses
Trade And Other Payables [Line Items]
Borrowings	65	288
Short-term payables	€ 36	€ 261