Retirement benefits (Tables)

6 Months Ended

Jun. 30, 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 June 30,
Service cost	$	—	—	1.9	2.0	1.9	2.0
Interest cost on projected benefit obligation	8.1		5.7	4.5	3.3	12.6	9.0
Return on assets – expected	(11.8)		(12.3)	(2.7)	(3.4)	(14.5)	(15.7)
Amortization of losses	0.4		6.3	0.4	0.5	0.8	6.8
Settlement loss	—		—	0.2	0.1	0.2	0.1
Net periodic pension cost	$	(3.3)	(0.3)	4.3	2.5	1.0	2.2
Six months ended June 30,
Service cost	$	—	—	3.7	4.1	3.7	4.1
Interest cost on projected benefit obligation	16.2		11.4	8.9	6.6	25.1	18.0
Return on assets – expected	(23.6)		(24.4)	(5.5)	(6.3)	(29.1)	(30.7)
Amortization of losses	0.9		12.1	0.8	1.0	1.7	13.1
Settlement loss	—		—	0.3	0.5	0.3	0.5
Net periodic pension cost	$	(6.5)	(0.9)	8.2	5.9	1.7	5.0

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 June 30,
Service cost	$	—	—	0.1	0.1	0.1	0.1
Interest cost on accumulated postretirement benefit obligations	2.7		2.6	1.3	0.9	4.0	3.5
Return on assets – expected	(2.6)		(3.3)	—	—	(2.6)	(3.3)
Amortization of losses	1.2		2.2	1.2	1.8	2.4	4.0
Amortization of prior service cost	(2.8)		(1.1)	—	(0.1)	(2.8)	(1.2)
Net periodic postretirement cost	$	(1.5)	0.4	2.6	2.7	1.1	3.1
Six months ended June 30,
Service cost	$	—	—	0.2	0.1	0.2	0.1
Interest cost on accumulated postretirement benefit obligations	5.7		5.3	2.6	1.8	8.3	7.1
Return on assets – expected	(5.2)		(6.6)	—	—	(5.2)	(6.6)
Amortization of losses	2.9		5.3	2.3	3.7	5.2	9.0
Amortization of prior service cost	(5.5)		(2.3)	—	(0.1)	(5.5)	(2.4)
Net periodic postretirement cost	$	(2.1)	1.7	5.1	5.5	3.0	7.2