Employee Benefits - Weighted-average assumptions used to determine the net periodic benefit cost (Details) - Pension Plan	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
U.K.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.95%	1.85%	1.20%
Expected return on plan assets, net of administration expenses	5.34%	2.34%	2.04%
U.K. | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Rate of compensation increase	3.59%	3.62%	3.22%
U.K. | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Rate of compensation increase	4.09%	4.12%	3.72%
Other | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.35%	0.84%	0.28%
Expected return on plan assets, net of administration expenses	4.20%	1.80%	1.70%
Rate of compensation increase	1.00%	1.00%	1.00%
Other | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	5.15%	2.58%	2.00%
Expected return on plan assets, net of administration expenses	4.85%	3.15%	2.65%
Rate of compensation increase	3.00%	3.00%	3.00%
U.S. | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.80%	1.67%	1.12%
Expected return on plan assets, net of administration expenses	6.82%	2.03%	2.65%
U.S. | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.91%	2.25%	1.79%
Expected return on plan assets, net of administration expenses		5.28%	6.56%