Financial instruments fair value risk - Summary of Reconciliation of Movements in Level 3 Valuations (Details) - At fair value - Level 3 - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Disclosure of Fair Value Measurement of Assets [Line Items]
Assets and liabilities at beginning of period	€ 962	€ 684
Gains/(losses) recognised in income statement	(46)	(58)
Gains/(losses) recognised in other comprehensive income	(22)	67
Purchases and new issues	30	135
Sales and settlements	(80)	134
Assets and liabilities at end of period	€ 844	€ 962

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

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Financial assets and financial liabilities at fair value.

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- Definition

Gains (losses) recognised in other comprehensive income, fair value measurement, Assets Liabilities.

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- Definition

Gains (losses) recognised in profit or loss, fair value measurement, assets and liabilities.

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- Definition

Purchases and new issues, fair value measurement, assets and liabilities.

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- Definition

Sales and Settlements, fair value measurement, assets and liabilities.

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