Defined contribution and defined benefit retirement plans - Summary of Actuarial Assumptions Used to Determine Net Periodic Benefit Cost (Credit) (Details) - Pension Plans	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
UNITED STATES
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Discount rate	5.50%	5.00%	5.30%
Long-term return on plan assets	5.00%	5.00%	5.00%
Non-U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Discount rate	3.60%	3.40%	3.90%
Increase in future compensation levels	2.80%	2.70%	2.70%
Long-term return on plan assets	4.50%	4.90%	4.60%