Investments Accounted for Using the Equity Method - Summary of Principal Transactions and Balances with Related Parties (Details) - EUR (€) € in Millions |
6 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
Oct. 31, 2024 |
|||||||||
| Disclosure of transactions between related parties [line items] | ||||||||||||
| Other Assets | € 189 | € 189 | ||||||||||
| Subordinate Hybrid Bond, Related Party Transactions | € 200 | |||||||||||
| Associates and joint ventures | ||||||||||||
| Disclosure of transactions between related parties [line items] | ||||||||||||
| Sales | [1],[2] | 29 | € 59 | |||||||||
| Royalties and other income | [1],[2] | 63 | 33 | |||||||||
| Accounts receivable and other receivables | [3] | 299 | 184 | |||||||||
| Other Assets | [4] | 189 | 189 | |||||||||
| Purchases of goods and services (including research expenses) | [1],[2] | 371 | € 333 | |||||||||
| Amounts payable, related party transactions | € 637 | € 160 | ||||||||||
| ||||||||||||