Retirement benefits (Tables)

9 Months Ended

Sep. 30, 2022

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)	2022		2021	2022	2021	2022	2021
Three months ended September 30,
Service cost	$	—	—	2.0	2.1	2.0	2.1
Interest cost on projected benefit obligation	5.8		5.3	3.2	3.0	9.0	8.3
Return on assets – expected	(12.1)		(11.8)	(3.2)	(3.1)	(15.3)	(14.9)
Amortization of losses	5.9		8.4	0.5	1.7	6.4	10.1
Amortization of prior service credit	—		—	(0.1)	—	(0.1)	—
Settlement loss	—		—	0.1	0.3	0.1	0.3
Net periodic pension cost	$	(0.4)	1.9	2.5	4.0	2.1	5.9
Nine months ended September 30,
Service cost	$	—	—	6.1	6.8	6.1	6.8
Interest cost on projected benefit obligation	17.2		15.9	9.8	9.0	27.0	24.9
Return on assets – expected	(36.5)		(35.5)	(9.5)	(9.3)	(46.0)	(44.8)
Amortization of losses	18.0		25.4	1.5	5.0	19.5	30.4
Amortization of prior service cost	—		—	(0.1)	(0.1)	(0.1)	(0.1)
Curtailment gain	—		—	—	(0.6)	—	(0.6)
Settlement loss	—		—	0.6	1.0	0.6	1.0
Net periodic pension cost	$	(1.3)	5.8	8.4	11.8	7.1	17.6

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)	2022		2021	2022	2021	2022	2021
Three months ended September 30,
Interest cost on accumulated postretirement benefit obligations	$	2.5	2.4	0.9	0.8	3.4	3.2
Return on assets – expected	(3.3)		(3.1)	—	—	(3.3)	(3.1)
Amortization of losses	2.4		4.3	1.8	2.3	4.2	6.6
Amortization of prior service cost	(1.2)		(1.2)	(0.1)	—	(1.3)	(1.2)
Net periodic postretirement cost	$	0.4	2.4	2.6	3.1	3.0	5.5
Nine months ended September 30,
Service cost	$	—	—	0.1	0.1	0.1	0.1
Interest cost on accumulated postretirement benefit obligations	7.8		7.3	2.7	2.4	10.5	9.7
Return on assets – expected	(9.9)		(9.2)	—	—	(9.9)	(9.2)
Amortization of losses	7.7		13.3	5.5	6.7	13.2	20.0
Amortization of prior service cost	(3.5)		(3.5)	(0.2)	(0.2)	(3.7)	(3.7)
Net periodic postretirement cost	$	2.1	7.9	8.1	9.0	10.2	16.9