Retirement benefits (Tables)

3 Months Ended

Mar. 31, 2021

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)	2021		2020	2021	2020	2021	2020
Three months ended March 31,
Service cost	$	—	—	2.2	2.9	2.2	2.9
Interest cost on projected benefit obligation	5.3		6.6	2.9	2.4	8.2	9.0
Return on assets – expected	(11.8)		(11.5)	(3.1)	(2.6)	(14.9)	(14.1)
Amortization of losses	8.4		6.9	1.6	1.2	10.0	8.1
Settlement loss	—		—	0.4	0.4	0.4	0.4
Net periodic pension cost	$	1.9	2.0	4.0	4.3	5.9	6.3

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)	2021		2020	2021	2020	2021	2020
Three months ended March 31,
Interest cost on accumulated postretirement benefit obligations	$	2.5	3.3	0.8	0.9	3.3	4.2
Return on assets – expected	(3.1)		(3.3)	—	—	(3.1)	(3.3)
Amortization of losses	4.8		4.0	2.1	2.0	6.9	6.0
Amortization of prior service credit	(1.2)		(1.2)	—	—	(1.2)	(1.2)
Net periodic postretirement cost	$	3.0	2.8	2.9	2.9	5.9	5.7