Tax matters - Schedule of tax recognized in equity (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Other comprehensive income
Items not reclassified to profit or loss	€ 115	€ 85	€ 358
Actuarial gains or (-) losses on defined benefit pension plans	63	172	302
Changes in the fair value of equity instruments measured at fair value through other comprehensive income	4	(4)	20
Financial liabilities at fair value with changes in results attributable to changes in credit risk	48	(83)	36
Items that may be reclassified to profit or loss	(440)	54	(919)
Cash flow hedges	(207)	(205)	(732)
Changes in the fair value of debt instruments through other comprehensive income	(204)	261	(214)
Hedging instruments (items not designated)	3	0	0
Non-current assets held for sale	(32)	0	0
Other recognised income and expense of investments in subsidiaries, joint ventures and associates	0	(2)	27
Total	€ (325)	€ 139	€ (561)

The amount of income tax relating to amounts recognised in other comprehensive income in relation to cash flow hedges. [Refer: Cash flow hedges [member]; Other comprehensive income]

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to changes in the fair value of financial liabilities attributable to a change in the credit risk of those liabilities. [Refer: Credit risk [member]; Other comprehensive income]

+ References

+ Details

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income. [Refer: Other comprehensive income]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2025-01-01
-Paragraph 81
-Subparagraph ab
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_ab&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 194
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_194_b&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 194
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_194_b&doctype=Standard
-URIDate 2025-03-27

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 90
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_90&doctype=Standard
-URIDate 2025-03-27

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- References

No definition available.

+ Details

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to financial assets measured at fair value through other comprehensive income applying paragraph 4.1.2A of IFRS 9. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income]

+ References

+ Details

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to hedges of investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: Other comprehensive income; Reserve of gains and losses on hedging instruments that hedge investments in equity instruments]

+ References

+ Details

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to hedges of net investments in foreign operations. [Refer: Other comprehensive income]

+ References

+ Details

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income in relation to remeasurements of defined benefit plans. [Refer: Other comprehensive income; Reserve of remeasurements of defined benefit plans; Defined benefit plans [domain]]

+ References

+ Details

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- Definition

The amount of income tax relating to an entity's share of other comprehensive income of associates and joint ventures accounted for using the equity method that will be reclassified to profit or loss. [Refer: Share of other comprehensive income of associates and joint ventures accounted for using equity method, before tax]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 91
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_91&doctype=Standard
-URIDate 2025-03-27

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income that will be reclassified to profit or loss, including share of OCI of associates and joint ventures accounted for using the equity method.

+ References

No definition available.

+ Details

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- Definition

The amount of income tax relating to amounts recognised in other comprehensive income that will not be reclassified to profit or loss including share of OCI of associates and joint ventures accounted for using equity method.

+ References

No definition available.

+ Details

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- Definition

Income Tax Relating To Non Current Assets Held For Sale Included In Other Comprehensive Income

+ References

No definition available.

+ Details

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