Retirement benefits (Tables)

3 Months Ended

Mar. 31, 2023

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

The components of net periodic pension cost for our pension plans were as follows:

	U.S. Plans			Non-U.S. Plans		Total
(In millions)	2023		2022	2023	2022	2023	2022
Three months ended March 31,
Service cost	$	—	—	1.8	2.1	1.8	2.1
Interest cost on projected benefit obligation	8.1		5.7	4.4	3.3	12.5	9.0
Return on assets – expected	(11.8)		(12.1)	(2.8)	(2.9)	(14.6)	(15.0)
Amortization of losses	0.5		5.8	0.4	0.5	0.9	6.3
Settlement loss	—		—	0.1	0.4	0.1	0.4
Net periodic pension cost	$	(3.2)	(0.6)	3.9	3.4	0.7	2.8

Schedule of Costs of Retirement Plans

The components of net periodic postretirement cost related to retirement benefits other than pensions were as follows:

	UMWA Plans			Black Lung and Other Plans		Total
(In millions)	2023		2022	2023	2022	2023	2022
Three months ended March 31,
Service cost	$	—	—	0.1	—	0.1	—
Interest cost on accumulated postretirement benefit obligations	3.0		2.7	1.3	0.9	4.3	3.6
Return on assets – expected	(2.6)		(3.3)	—	—	(2.6)	(3.3)
Amortization of losses	1.7		3.1	1.1	1.9	2.8	5.0
Amortization of prior service cost	(2.7)		(1.2)	—	—	(2.7)	(1.2)
Net periodic postretirement cost	$	(0.6)	1.3	2.5	2.8	1.9	4.1