Loans and advances to customers - Summary (Details) - EUR (€) € in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans And Advances To Customers Line Items
Financial assets held for trading	€ 125,458	€ 148,187	€ 146,346
Financial assets designated at fair value through profit or loss	34,782	31,609	45,043
Loans and receivables	903,013	840,004	836,156
Loans and advances to customers	848,915	790,470	790,848
Loans and advances
Loans And Advances To Customers Line Items
Financial assets held for trading	10,511	12,725	7,433
Financial assets designated at fair value through profit or loss	30,364	27,665	40,696
Loans and receivables	885,470	826,767	825,249
Loans and advances - Customers
Loans And Advances To Customers Line Items
Financial assets held for trading	8,815	9,504	6,081
Financial assets designated at fair value through profit or loss	20,475	17,596	14,293
Loans and receivables	819,625	763,370	770,474
Impairment losses	(23,934)	(24,393)	(26,517)	€ (27,217)
Loans and advances to customers	848,915	790,470	790,848
Loans and advances - Customers \| Gross carrying amount
Loans And Advances To Customers Line Items
Loans and receivables	843,559	787,763	796,991
Loans and advances to customers	872,849	814,863	817,365
Loans and advances - Customers \| Impairment losses
Loans And Advances To Customers Line Items
Loans and receivables	23,934	24,393	26,517
Loans and advances - Customers \| Country risk \| Impairment losses
Loans And Advances To Customers Line Items
Loans and receivables	€ 18	€ 15	€ 12

The amount of an allowance account used to record impairments to financial assets due to credit losses. [Refer: Financial assets]

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The amount of financial assets at fair value through profit or loss classified as held for trading. A financial asset is classified as held for trading if: (a) it is acquired principally for the purpose of selling it in the near term; (b) on initial recognition it is part of a portfolio of identified financial instruments that are managed together and for which there is evidence of a recent actual pattern of short-term profit-taking; or (c) it is a derivative (except for a derivative that is a financial guarantee contract or a designated and effective hedging instrument). [Refer: At fair value [member]; Financial assets at fair value through profit or loss]

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The amount of financial assets at fair value through profit or loss that were designated as such upon initial recognition or subsequently. [Refer: At fair value [member]; Financial assets at fair value through profit or loss]

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The amount of loans and advances the entity has made to customers.

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The amount of non-derivative financial assets with fixed or determinable payments that are not quoted in an active market, other than: (a) those that the entity intends to sell immediately or in the near term, which shall be classified as held for trading, and those that the entity, upon initial recognition, designates as at fair value through profit or loss; (b) those that the entity, upon initial recognition, designates as available for sale; or (c) those for which the holder may not recover substantially all of its initial investment, other than because of credit deterioration, which shall be classified as available for sale. An interest acquired in a pool of assets that are not loans or receivables (for example, an interest in a mutual fund or a similar fund) is not a loan or receivable. [Refer: Derivative financial assets]

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