Retirement benefits (Tables)

3 Months Ended

Mar. 31, 2020

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)	2020			2019		2020		2019		2020		2019
Three months ended March 31,
Service cost	$	—		—		2.9		2.5		2.9		2.5
Interest cost on projected benefit obligation	6.6			8.5		2.4		2.6		9.0		11.1
Return on assets – expected	(11.5		)	(12.7	)	(2.6	)	(2.6	)	(14.1	)	(15.3	)
Amortization of losses	6.9			5.0		1.2		1.0		8.1		6.0
Settlement loss	—			—		0.4		0.3		0.4		0.3
Net periodic pension cost	$	2.0		0.8		4.3		3.8		6.3		4.6

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)	2020			2019		2020	2019		2020		2019
Three months ended March 31,
Interest cost on accumulated postretirement benefit obligations	$	3.3		5.0		0.9	0.9		4.2		5.9
Return on assets – expected	(3.3		)	(3.3	)	—	—		(3.3	)	(3.3	)
Amortization of losses	4.0			5.1		2.0	1.1		6.0		6.2
Amortization of prior service credit	(1.2		)	(1.1	)	—	(0.1	)	(1.2	)	(1.2	)
Net periodic postretirement cost	$	2.8		5.7		2.9	1.9		5.7		7.6