Retirement benefits (Tables)

6 Months Ended

Jun. 30, 2016

Compensation and Retirement Disclosure [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)	2016			2015		2016		2015		2016		2015
Three months ended June 30,
Service cost	$	—		—		2.7		2.6		2.7		2.6
Interest cost on projected benefit obligation	9.3			9.0		3.1		3.0		12.4		12.0
Return on assets – expected	(13.6		)	(13.6	)	(2.5	)	(2.4	)	(16.1	)	(16.0	)
Amortization of losses	6.2			7.7		1.2		1.2		7.4		8.9
Amortization of prior service cost	—			—		0.2		0.2		0.2		0.2
Settlement loss	—			—		0.6		1.1		0.6		1.1
Net periodic pension cost	$	1.9		3.1		5.3		5.7		7.2		8.8
Included in:
Continuing operations	$	1.9		3.1		5.3		5.7		7.2		8.8
Discontinued operations	—			—		—		—		—		—
Net periodic pension cost	$	1.9		3.1		5.3		5.7		7.2		8.8
Six months ended June 30,
Service cost	$	—		—		5.5		5.5		5.5		5.5
Interest cost on projected benefit obligation	18.5			18.0		6.5		6.2		25.0		24.2
Return on assets – expected	(27.3		)	(27.3	)	(4.8	)	(4.8	)	(32.1	)	(32.1	)
Amortization of losses	12.3			15.5		2.4		2.5		14.7		18.0
Amortization of prior service cost	—			—		0.2		0.2		0.2		0.2
Settlement loss	—			—		1.4		3.4		1.4		3.4
Net periodic pension cost	$	3.5		6.2		11.2		13.0		14.7		19.2
Included in:
Continuing operations	$	3.5		6.2		11.2		11.9		14.7		18.1
Discontinued operations	—			—		—		1.1		—		1.1
Net periodic pension cost	$	3.5		6.2		11.2		13.0		14.7		19.2

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)	2016			2015		2016	2015	2016		2015
Three months ended June 30,
Service cost	$	—		—		—	0.1	—		0.1
Interest cost on accumulated postretirement benefit obligations	4.8			4.2		0.7	0.7	5.5		4.9
Return on assets – expected	(4.3		)	(5.1	)	—	—	(4.3	)	(5.1	)
Amortization of losses	4.5			3.7		0.7	0.8	5.2		4.5
Amortization of prior service (credit) cost	(1.2		)	(1.1	)	0.4	0.4	(0.8	)	(0.7	)
Net periodic postretirement cost	$	3.8		1.7		1.8	2.0	5.6		3.7
Six months ended June 30,
Service cost	$	—		—		—	0.1	—		0.1
Interest cost on accumulated postretirement benefit obligations	9.4			8.7		1.3	1.4	10.7		10.1
Return on assets – expected	(8.7		)	(10.3	)	—	—	(8.7	)	(10.3	)
Amortization of losses	8.8			8.0		1.2	1.5	10.0		9.5
Amortization of prior service (credit) cost	(2.3		)	(2.3	)	0.9	0.9	(1.4	)	(1.4	)
Net periodic postretirement cost	$	7.2		4.1		3.4	3.9	10.6		8.0