Retirement Benefits - Assumptions (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement benefits other than pension
Defined Benefit Plan Disclosure [Line Items]
Pension cost	5.60%	2.90%	2.40%
Benefit obligation at year end	5.30%	5.60%	2.90%
Expected return on assets	8.00%	8.00%	8.00%
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Pension cost	5.40%	2.80%	2.40%
Benefit obligation at year end	5.10%	5.40%	2.80%
Expected return on assets	7.00%	7.00%	7.00%
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Pension cost	5.40%	2.80%	2.30%
Benefit obligation at year end	4.90%	5.40%	2.80%
Expected return on assets	4.59%	3.76%	3.55%
Average rate of increase in salaries - pension cost	1.90%	1.60%	1.90%
Average rate of increase in salaries - benefit obligation at year end	2.00%	1.90%	1.60%
UMWA Plans
Defined Benefit Plan Disclosure [Line Items]
Pension cost	5.40%	2.80%	2.30%
Benefit obligation at year end	5.10%	5.40%	2.80%
Black Lung and Other Plans
Defined Benefit Plan Disclosure [Line Items]
Pension cost	5.40%	2.70%	2.20%
Benefit obligation at year end	5.10%	5.40%	2.70%