Financial assets - Movement in provisions that cover impairment losses (Details) - EUR (€) € in Millions	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Disclosure of reconciliation of changes in loss allowance of financial instruments
Recorded impairment, net of recoveries	€ 4,368
Impairment loss on financial assets		€ 4,352
Financial assets at amortised cost, category
Disclosure of reconciliation of changes in loss allowance of financial instruments
Net impairment losses charged to income for the period	5,199	5,174
Impairment losses charged to income	9,697	9,042
Impairment losses reversed with a credit to income	(4,498)	(3,868)
Write-off of impaired assets against recorded allowance	(6,246)	(6,140)
Exchange differences and other	434	(749)
Previously written-off assets recovered	837	823
Recorded impairment, net of recoveries	4,362
Impairment loss on financial assets		4,351
Financial assets at amortised cost, category \| Accumulated impairment
Disclosure of reconciliation of changes in loss allowance of financial instruments
Financial assets at beginning of period	(23,945)	(26,656)
Financial assets at end of period	(23,332)	(24,941)
Financial instruments credit-impaired \| Financial assets at amortised cost, category \| Accumulated impairment
Disclosure of reconciliation of changes in loss allowance of financial instruments
Financial assets at end of period	(15,110)	(16,131)
Financial instruments not credit-impaired [member] \| Financial assets at amortised cost, category \| Accumulated impairment
Disclosure of reconciliation of changes in loss allowance of financial instruments
Financial assets at end of period	(8,222)	(8,810)
Expected credit losses individually assessed [member] \| Financial assets at amortised cost, category \| Accumulated impairment
Disclosure of reconciliation of changes in loss allowance of financial instruments
Financial assets at end of period	(4,983)	(6,146)
Expected credit losses collectively assessed [member] \| Financial assets at amortised cost, category \| Accumulated impairment
Disclosure of reconciliation of changes in loss allowance of financial instruments
Financial assets at end of period	€ (18,349)	€ (18,795)

The decrease in financial assets resulting from write-off. [Refer: Financial assets]

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The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) 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 receive 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 the entity’s own equity instruments do not include puttable financial instruments 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. [Refer: Financial instruments, class [member]; Financial liabilities]

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The gain on the recovery of loans and advances previously written off.

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The amount of impairment loss, impairment gain or reversal of impairment loss that is recognised in profit or loss in accordance with paragraph 5.5.8 of IFRS 9 and that arises from applying the impairment requirements in Section 5.5 of IFRS 9.

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The amount of impairment loss on financial assets. [Refer: Financial assets; Impairment loss]

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The increase (decrease) in financial assets resulting from foreign exchange and other movements. [Refer: Financial assets]

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