Defined benefit pension plans - Components of Net Periodic Defined Benefit Pension Benefit Cost (Details) - Defined Benefit Pension Plans - USD ($) $ in Millions		12 Months Ended
	Dec. 16, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
UNITED STATES
Defined benefit pension plans [Line Items]
Interest cost		$ 3.4	$ 2.7	$ 2.2
Expected return on plan assets		(3.6)	(3.2)	(1.9)
Recognized net actuarial losses		1.4	1.9	2.0
Settlements	$ 28.7	28.7
Total		29.9	1.4	2.3
Non-U.S.
Defined benefit pension plans [Line Items]
Service cost		6.0	6.6	6.3
Interest cost		19.9	18.9	19.8
Expected return on plan assets		(19.2)	(19.9)	(18.3)
Recognized net actuarial losses		1.7	1.9	1.8
Amortization of prior service cost		0.1	0.1
Settlements		0.3	0.4	6.5
Total		$ 8.8	$ 8.0	$ 16.1