Provisions, income tax liabilities and other liabilities - Expected Timing of Benefit Payments under Pension and Other Post-employment Benefit Plans (Details) € in Millions	Dec. 31, 2023 EUR (€)
Year 1
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	€ 579
Year 2
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	545
Year 3
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	556
Year 4
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	584
Year 5
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	616
2029 to 2033
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	3,213
France \| Year 1
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	103
France \| Year 2
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	68
France \| Year 3
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	60
France \| Year 4
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	79
France \| Year 5
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	93
France \| 2029 to 2033
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	438
Germany \| Year 1
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	198
Germany \| Year 2
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	212
Germany \| Year 3
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	218
Germany \| Year 4
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	221
Germany \| Year 5
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	229
Germany \| 2029 to 2033
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	1,190
US \| Year 1
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	102
US \| Year 2
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	91
US \| Year 3
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	95
US \| Year 4
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	98
US \| Year 5
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	101
US \| 2029 to 2033
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	526
UK \| Year 1
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	116
UK \| Year 2
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	120
UK \| Year 3
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	123
UK \| Year 4
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	127
UK \| Year 5
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	131
UK \| 2029 to 2033
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	716
Other \| Year 1
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	60
Other \| Year 2
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	54
Other \| Year 3
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	60
Other \| Year 4
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	59
Other \| Year 5
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	62
Other \| 2029 to 2033
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	€ 343

Provisions, income tax liabilities and other liabilities - Expected Timing of Benefit Payments under Pension and Other Post-employment Benefit Plans (Details)
€ in Millions