Financial Liabilities - Maturity Analysis of Financial Liabilities (Details) - EUR (€) € in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total Issues	€ 41,995
Loans and other payables	4,488	€ 8,555
Telefonica, S.A.
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	42,636
Promissory notes & commercial paper	2,358
Total Issues	44,994
Loans and other payables	4,488
Derivative instruments (Note 16)	2,882
Total	52,364	€ 54,702
Telefonica, S.A. \| 2020
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	5,826
Promissory notes & commercial paper	1,635
Total Issues	7,461
Loans and other payables	1,091
Derivative instruments (Note 16)	524
Total	9,076
Telefonica, S.A. \| 2021
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	4,876
Promissory notes & commercial paper	0
Total Issues	4,876
Loans and other payables	447
Derivative instruments (Note 16)	199
Total	5,522
Telefonica, S.A. \| 2022
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	5,152
Promissory notes & commercial paper	0
Total Issues	5,152
Loans and other payables	380
Derivative instruments (Note 16)	228
Total	5,760
Telefonica, S.A. \| 2023
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	2,369
Promissory notes & commercial paper	140
Total Issues	2,509
Loans and other payables	423
Derivative instruments (Note 16)	101
Total	3,033
Telefonica, S.A. \| 2024
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	1,048
Promissory notes & commercial paper	263
Total Issues	1,311
Loans and other payables	547
Derivative instruments (Note 16)	132
Total	1,990
Telefonica, S.A. \| Subsequent years
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	23,365
Promissory notes & commercial paper	320
Total Issues	23,685
Loans and other payables	1,600
Derivative instruments (Note 16)	1,698
Total	26,983
Telefonica, S.A. \| Non-current
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debentures and bonds	36,810
Promissory notes & commercial paper	723
Total Issues	37,533
Loans and other payables	3,397
Derivative instruments (Note 16)	2,358
Total	€ 43,288

The amount of contractual undiscounted cash flows in relation to bank borrowings. [Refer: Borrowings]

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The amount of contractual undiscounted cash flows in relation to bonds issued. [Refer: Bonds issued]

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

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The amount of contractual undiscounted cash flows in relation to derivative financial liabilities. [Refer: Derivative financial liabilities]

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No definition available.

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The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity’s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity’s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Financial instruments, class [member]; Financial assets; Derivatives [member]]

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The amount of contractual undiscounted cash flows in relation to trade and other payables. [Refer: Trade and other payables]

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