Retirement benefits (Tables)

3 Months Ended

Mar. 31, 2019

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)	2019			2018		2019		2018		2019		2018
Three months ended March 31,
Service cost	$	—		—		2.5		3.0		2.5		3.0
Interest cost on projected benefit obligation	8.5			8.0		2.6		4.0		11.1		12.0
Return on assets – expected	(12.7		)	(13.4	)	(2.6	)	(2.9	)	(15.3	)	(16.3	)
Amortization of losses	5.0			7.1		1.0		1.3		6.0		8.4
Amortization of prior service cost	—			—		—		0.2		—		0.2
Settlement loss	—			—		0.3		0.5		0.3		0.5
Net periodic pension cost	$	0.8		1.7		3.8		6.1		4.6		7.8

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)	2019			2018		2019		2018	2019		2018
Three months ended March 31,
Interest cost on accumulated postretirement benefit obligations	$	5.0		4.5		0.9		0.7	5.9		5.2
Return on assets – expected	(3.3		)	(4.2	)	—		—	(3.3	)	(4.2	)
Amortization of losses	5.1			5.5		1.1		1.2	6.2		6.7
Amortization of prior service (credit) cost	(1.1		)	(1.1	)	(0.1	)	0.3	(1.2	)	(0.8	)
Net periodic postretirement cost	$	5.7		4.7		1.9		2.2	7.6		6.9