v3.26.1
Other disclosures - Schedule of effect on fair value of financial instruments classified as Level 3 of a reasonable change in the assumptions used in the valuation (Details)
€ in Thousands
6 Months Ended 12 Months Ended
Jun. 30, 2026
EUR (€)
Dec. 31, 2025
EUR (€)
Discounted cash flow | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value liabilities due to changes in inputs € (1,110) € (2,420)
Increase in fair value of liabilities due to change in inputs € 630 € 660
Discounted cash flow | Minimum | Credit spread, measurement input | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.0020 0.00084
Discounted cash flow | Maximum | Credit spread, measurement input | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.0037 0.00192
Discounted cash flow | Weighted average | Credit spread, measurement input | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.002620 0.001070
IR option pricing model | Financial liabilities held for trading | Caps/Floors    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value liabilities due to changes in inputs € (170) € (90)
Increase in fair value of liabilities due to change in inputs 140 70
IR option pricing model | Financial liabilities held for trading | Foreign Exchange Options    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value liabilities due to changes in inputs (710) (330)
Increase in fair value of liabilities due to change in inputs € 470 € 220
IR option pricing model | Minimum | Historical volatility for shares, measurement input | Financial liabilities held for trading | Caps/Floors    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.10 0.10
IR option pricing model | Minimum | Historical volatility for shares, measurement input | Financial liabilities held for trading | Foreign Exchange Options    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.10 0.10
IR option pricing model | Maximum | Historical volatility for shares, measurement input | Financial liabilities held for trading | Caps/Floors    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.90 0.90
IR option pricing model | Maximum | Historical volatility for shares, measurement input | Financial liabilities held for trading | Foreign Exchange Options    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.90 0.90
IR option pricing model | Weighted average | Historical volatility for shares, measurement input | Financial liabilities held for trading | Caps/Floors    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.4630 0.4380
IR option pricing model | Weighted average | Historical volatility for shares, measurement input | Financial liabilities held for trading | Foreign Exchange Options    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.4190 0.4230
Discounted Cash Flows On Inflation Swap Rate | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value liabilities due to changes in inputs € (20) € (1,380)
Increase in fair value of liabilities due to change in inputs € 20 € 1,400
Discounted Cash Flows On Inflation Swap Rate | Minimum | Inflation Swap Rate, Measurement Input | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.10 0.01
Discounted Cash Flows On Inflation Swap Rate | Maximum | Inflation Swap Rate, Measurement Input | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.90 0.99
Discounted Cash Flows On Inflation Swap Rate | Weighted average | Inflation Swap Rate, Measurement Input | Financial liabilities held for trading | Interest rate swap contract    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, liabilities 0.46 0.5040
Financial assets held for trading | Repos / Reverse Repos | Other Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (11,700) € (10,500)
Increase in fair value of assets due to change in inputs 11,700 10,500
Financial assets held for trading | Repos / Reverse Repos | Present Value Method    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs (7,970)  
Increase in fair value of assets due to change in inputs € 570  
Financial assets held for trading | Repos / Reverse Repos | Present Value Method | Minimum | Interest Rate Curve    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets (0.000490)  
Financial assets held for trading | Repos / Reverse Repos | Present Value Method | Maximum | Interest Rate Curve    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.006890  
Financial assets held for trading | Repos / Reverse Repos | Present Value Method | Weighted average | Interest Rate Curve    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.00  
Financial assets held for trading | Corporate Debt | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (2,060) (2,240)
Increase in fair value of assets due to change in inputs € 2,110 € 2,290
Financial assets held for trading | Corporate Debt | Discounted cash flow | Minimum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | Corporate Debt | Discounted cash flow | Maximum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.1000 0.10
Financial assets held for trading | Corporate Debt | Discounted cash flow | Weighted average | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0510 0.0510
Financial assets held for trading | Government Debt | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (9,970) € (9,210)
Increase in fair value of assets due to change in inputs € 9,900 € 9,240
Financial assets held for trading | Government Debt | Discounted cash flow | Minimum | Discount Curve, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | Government Debt | Discounted cash flow | Maximum | Discount Curve, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.08 0.08
Financial assets held for trading | Government Debt | Discounted cash flow | Weighted average | Discount Curve, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0400 0.0400
Financial assets held for trading | Debt Securities, Other | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (880) € (1,320)
Increase in fair value of assets due to change in inputs € 550 € 620
Financial assets held for trading | Debt Securities, Other | Discounted cash flow | Minimum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.10 0.10
Financial assets held for trading | Debt Securities, Other | Discounted cash flow | Maximum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.90 0.90
Financial assets held for trading | Debt Securities, Other | Discounted cash flow | Weighted average | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.4070 0.3550
Financial assets held for trading | Caps/Floors | Black Scholes Model    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (30) € (380)
Increase in fair value of assets due to change in inputs € 60 € 520
Financial assets held for trading | Caps/Floors | Black Scholes Model | Minimum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets (0.000650) (0.000650)
Financial assets held for trading | Caps/Floors | Black Scholes Model | Maximum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.000650 0.000650
Financial assets held for trading | Caps/Floors | Black Scholes Model | Weighted average | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.000260 0.000100
Financial assets held for trading | Currency swap contract | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs   € (10)
Increase in fair value of assets due to change in inputs   € 10
Financial assets held for trading | Currency swap contract | Discounted cash flow | Minimum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets   1.463
Financial assets held for trading | Currency swap contract | Discounted cash flow | Maximum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets   1.483
Financial assets held for trading | Currency swap contract | Discounted cash flow | Weighted average | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets   1.4730
Financial assets held for trading | EQ Options | EQ Option Pricing Model Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (700) € (170)
Increase in fair value of assets due to change in inputs € 720 € 240
Financial assets held for trading | EQ Options | EQ Option Pricing Model Valuation Technique | Minimum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | EQ Options | EQ Option Pricing Model Valuation Technique | Maximum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.70 0.70
Financial assets held for trading | EQ Options | EQ Option Pricing Model Valuation Technique | Weighted average | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.3550 0.4050
Financial assets held for trading | EQ Options | Local Volatility Option Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (35,740) € (18,860)
Increase in fair value of assets due to change in inputs € 35,740 € 18,860
Financial assets held for trading | EQ Options | Local Volatility Option Technique | Minimum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.10 0.10
Financial assets held for trading | EQ Options | Local Volatility Option Technique | Maximum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.90 0.90
Financial assets held for trading | EQ Options | Local Volatility Option Technique | Weighted average | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.5000 0.5000
Financial assets held for trading | Foreign Exchange Options | FX Option Pricing Model    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (390) € (500)
Increase in fair value of assets due to change in inputs € 380 € 490
Financial assets held for trading | Foreign Exchange Options | FX Option Pricing Model | Minimum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | Foreign Exchange Options | FX Option Pricing Model | Maximum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.40 0.40
Financial assets held for trading | Foreign Exchange Options | FX Option Pricing Model | Weighted average | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.1980 0.1980
Financial assets held for trading | Foreign Exchange Forward Contract | Forward Estimation Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (120) € (10)
Increase in fair value of assets due to change in inputs € 120 € 20
Financial assets held for trading | Foreign Exchange Forward Contract | Forward Estimation Valuation Technique | Minimum | Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | Foreign Exchange Forward Contract | Forward Estimation Valuation Technique | Maximum | Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.15 0.15
Financial assets held for trading | Foreign Exchange Forward Contract | Forward Estimation Valuation Technique | Weighted average | Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0760 0.0810
Financial assets held for trading | Inflation Derivatives | Asset Swap Model Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (180) € (180)
Increase in fair value of assets due to change in inputs € 170 € 170
Financial assets held for trading | Inflation Derivatives | Asset Swap Model Valuation Technique | Minimum | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.02 0.02
Financial assets held for trading | Inflation Derivatives | Asset Swap Model Valuation Technique | Maximum | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.08 0.08
Financial assets held for trading | Inflation Derivatives | Asset Swap Model Valuation Technique | Weighted average | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0490 0.0490
Financial assets held for trading | IR Options | Interest Rate Option Pricing Model    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (180) € (190)
Increase in fair value of assets due to change in inputs € 180 € 190
Financial assets held for trading | IR Options | Interest Rate Option Pricing Model | Minimum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | IR Options | Interest Rate Option Pricing Model | Maximum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.30 0.30
Financial assets held for trading | IR Options | Interest Rate Option Pricing Model | Weighted average | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.1480 0.1480
Financial assets held for trading | IR Options | Inflation Option Pricing Model    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (600) € (630)
Increase in fair value of assets due to change in inputs € 590 € 630
Financial assets held for trading | IR Options | Inflation Option Pricing Model | Minimum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets held for trading | IR Options | Inflation Option Pricing Model | Maximum | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.30 0.30
Financial assets held for trading | IR Options | Inflation Option Pricing Model | Weighted average | Historical volatility for shares, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.1490 0.1490
Financial assets held for trading | Interest rate swap contract | Other Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (4,880) € (11,240)
Increase in fair value of assets due to change in inputs € 3,080 € 8,230
Financial assets held for trading | Interest rate swap contract | Other Valuation Technique | Minimum | Other Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.05 0.05
Financial assets held for trading | Interest rate swap contract | Discounted Cash Flows on credit spread    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (2,290) € (2,100)
Increase in fair value of assets due to change in inputs € 1,440 € 840
Financial assets held for trading | Interest rate swap contract | Discounted Cash Flows on credit spread | Minimum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.000910 0.196
Financial assets held for trading | Interest rate swap contract | Discounted Cash Flows on credit spread | Maximum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.006970 1.275
Financial assets held for trading | Interest rate swap contract | Discounted Cash Flows on credit spread | Weighted average | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.003240 0.5050
Financial assets held for trading | Interest rate swap contract | Flow Discounting Method On Inflation Swap Rate    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (2,190) € 0
Increase in fair value of assets due to change in inputs € 1,180 € 1,410
Financial assets held for trading | Interest rate swap contract | Flow Discounting Method On Inflation Swap Rate | Minimum | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.010 0.010
Financial assets held for trading | Interest rate swap contract | Flow Discounting Method On Inflation Swap Rate | Maximum | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.990 0.990
Financial assets held for trading | Interest rate swap contract | Flow Discounting Method On Inflation Swap Rate | Weighted average | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.3530 0.9900
Financial assets held for trading | Other IR derivatives | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (970)  
Increase in fair value of assets due to change in inputs 970  
Financial assets held for trading | Others | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs (0)  
Increase in fair value of assets due to change in inputs € 0  
Financial assets held for trading | Others | Discounted cash flow | Minimum | Commodity Curve, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.100  
Financial assets held for trading | Others | Discounted cash flow | Maximum | Commodity Curve, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.900  
Financial assets held for trading | Others | Discounted cash flow | Weighted average | Commodity Curve, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.1000  
Financial assets held for trading | Others | Forward Estimation Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (3,370) € (3,480)
Increase in fair value of assets due to change in inputs € 3,350 € 3,470
Financial assets held for trading | Others | Forward Estimation Valuation Technique | Minimum | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0060 0.0060
Financial assets held for trading | Others | Forward Estimation Valuation Technique | Maximum | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0300 0.0300
Financial assets held for trading | Others | Forward Estimation Valuation Technique | Weighted average | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.017980 0.01798
Financial assets held for trading | Property Derivatives | Option pricing model    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (2,320) € (2,640)
Increase in fair value of assets due to change in inputs € 2,320 € 2,640
Financial assets held for trading | Property Derivatives | Option pricing model | Minimum | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets (0.050) (0.05)
Financial assets held for trading | Property Derivatives | Option pricing model | Maximum | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.050 0.05
Financial assets held for trading | Property Derivatives | Option pricing model | Weighted average | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0000 0.0000
Financial assets held for trading | Securitisation Swap | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (11,780) € 0
Increase in fair value of assets due to change in inputs € 14,400 € 0
Financial assets held for trading | Securitisation Swap | Discounted cash flow | Minimum | Constant prepayment rate, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.100 0.10
Financial assets held for trading | Securitisation Swap | Discounted cash flow | Maximum | Constant prepayment rate, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.900 0.90
Financial assets held for trading | Securitisation Swap | Discounted cash flow | Weighted average | Constant prepayment rate, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.5400 0.5000
Financial assets designated at fair value through profit or loss | Debt Securities, Other | Other Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (3,870) € 0
Increase in fair value of assets due to change in inputs € 3,790 € 0
Financial assets designated at fair value through profit or loss | Debt Securities, Other | Other Valuation Technique | Minimum | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0
Financial assets designated at fair value through profit or loss | Debt Securities, Other | Other Valuation Technique | Maximum | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.08 0.08
Financial assets designated at fair value through profit or loss | Debt Securities, Other | Other Valuation Technique | Weighted average | Inflation Swap Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.04 0.0410
Financial assets designated at fair value through profit or loss | Loans | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs   € (120)
Increase in fair value of assets due to change in inputs   € 120
Financial assets designated at fair value through profit or loss | Loans | Discounted cash flow | Minimum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets   0.001
Financial assets designated at fair value through profit or loss | Loans | Discounted cash flow | Maximum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets   0.03
Financial assets designated at fair value through profit or loss | Loans | Discounted cash flow | Weighted average | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets   0.0160
Financial assets designated at fair value through profit or loss | Mortgage Portfolio | Black Scholes Model    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (120) € (230)
Increase in fair value of assets due to change in inputs € 120 € 230
Financial assets designated at fair value through profit or loss | Mortgage Portfolio | Black Scholes Model | Minimum | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets (0.05) (0.05)
Financial assets designated at fair value through profit or loss | Mortgage Portfolio | Black Scholes Model | Maximum | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.05 0.05
Financial assets designated at fair value through profit or loss | Mortgage Portfolio | Black Scholes Model | Weighted average | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0000 0.0000
Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities | Probability Weighting Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € 0 € (110)
Increase in fair value of assets due to change in inputs € 0 € 110
Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities | Probability Weighting Valuation Technique | Minimum | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets (0.05) (0.05)
Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities | Probability Weighting Valuation Technique | Maximum | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.05 0.05
Non-trading financial assets mandatorily at fair value through profit or loss | Debt securities | Probability Weighting Valuation Technique | Weighted average | Growth Rate, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0 0.0000
Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments | Price Based Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (260,300) € (254,290)
Increase in fair value of assets due to change in inputs € 260,300 € 254,290
Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments | Price Based Valuation Technique | Minimum | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.90 0.90
Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments | Price Based Valuation Technique | Maximum | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 1.10 1.10
Non-trading financial assets mandatorily at fair value through profit or loss | Equity instruments | Price Based Valuation Technique | Weighted average | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 1 1.0000
Financial assets at fair value through other comprehensive income | Loans | Present Value Method    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (20) € (1,600)
Increase in fair value of assets due to change in inputs € 0 € 0
Financial assets at fair value through other comprehensive income | Loans | Present Value Method | Minimum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.01857 0.01219
Financial assets at fair value through other comprehensive income | Loans | Present Value Method | Maximum | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.01193 0.01747
Financial assets at fair value through other comprehensive income | Loans | Present Value Method | Weighted average | Credit spread, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.018570 0.01219
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows on credit spread    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (25,340) € (2,330)
Increase in fair value of assets due to change in inputs 9,260 2,330
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Interest Rate Curve    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs (0) 0
Increase in fair value of assets due to change in inputs € 0 € 0
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Interest Rate Curve | Minimum | Interest rate, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.046 0.061
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Interest Rate Curve | Maximum | Interest rate, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.071 0.072
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Interest Rate Curve | Weighted average | Interest rate, measurement input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0580 0.066
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Margin Of A Reference Portfolio    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (590) € (250)
Increase in fair value of assets due to change in inputs € 590 € 250
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Margin Of A Reference Portfolio | Minimum | Margin Of A Preference Portfolio, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.028 0.033
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Margin Of A Reference Portfolio | Maximum | Margin Of A Preference Portfolio, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.065 0.065
Financial assets at fair value through other comprehensive income | Loans | Discounted Cash Flows On Margin Of A Reference Portfolio | Weighted average | Margin Of A Preference Portfolio, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0470 0.05
Financial assets at fair value through other comprehensive income | Loans | Market comparable prices    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (8,940) € (2,700)
Increase in fair value of assets due to change in inputs € 8,940 € 540
Financial assets at fair value through other comprehensive income | Loans | Market comparable prices | Minimum | Market Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets (0.005) (0.003)
Financial assets at fair value through other comprehensive income | Loans | Market comparable prices | Maximum | Market Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.005 0.001
Financial assets at fair value through other comprehensive income | Loans | Market comparable prices | Weighted average | Market Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0000 (0.0030)
Financial assets at fair value through other comprehensive income | Equity instruments | Price Based Valuation Technique    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (27,260) € (27,160)
Increase in fair value of assets due to change in inputs € 27,260 € 27,160
Financial assets at fair value through other comprehensive income | Equity instruments | Price Based Valuation Technique | Minimum | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.90 0.90
Financial assets at fair value through other comprehensive income | Equity instruments | Price Based Valuation Technique | Maximum | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 1.10 1.10
Financial assets at fair value through other comprehensive income | Equity instruments | Price Based Valuation Technique | Weighted average | Price, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 1.0000 1.0000
Financial assets at fair value through other comprehensive income | Mortgage Letters, Debt Securities | Discounted cash flow    
Disclosure of detailed information about financial instruments [line items]    
Decrease in fair value assets due to changes in inputs € (0) € 0
Increase in fair value of assets due to change in inputs € 0 € 0
Financial assets at fair value through other comprehensive income | Mortgage Letters, Debt Securities | Discounted cash flow | Minimum | Mortgage Letters, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.032 0.034
Financial assets at fair value through other comprehensive income | Mortgage Letters, Debt Securities | Discounted cash flow | Maximum | Mortgage Letters, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.083 0.055
Financial assets at fair value through other comprehensive income | Mortgage Letters, Debt Securities | Discounted cash flow | Weighted average | Mortgage Letters, Measurement Input    
Disclosure of detailed information about financial instruments [line items]    
Significant unobservable input, assets 0.0570 0.0450