Retirement benefits (Tables)
 9 Months Ended
Sep. 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 September 30,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Service cost
$
—

 
—

 
2.6

 
2.6

 
2.6

 
2.6

Interest cost on projected benefit obligation
9.3

 
9.0

 
3.0

 
2.9

 
12.3

 
11.9

Return on assets – expected
(13.7
)
 
(13.6
)
 
(2.4
)
 
(2.4
)
 
(16.1
)
 
(16.0
)
Amortization of losses
6.4

 
7.7

 
1.2

 
1.1

 
7.6

 
8.8

Settlement loss
—

 
—

 
0.4

 
1.5

 
0.4

 
1.5

Net periodic pension cost
$
2.0

 
3.1

 
4.8

 
5.7

 
6.8

 
8.8

 
 
 
 
 
 
 
 
 
 
 
 
Nine months ended September 30,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Service cost
$
—

 
—

 
8.1

 
8.1

 
8.1

 
8.1

Interest cost on projected benefit obligation
27.8

 
27.0

 
9.5

 
9.1

 
37.3

 
36.1

Return on assets – expected
(41.0
)
 
(40.9
)
 
(7.2
)
 
(7.2
)
 
(48.2
)
 
(48.1
)
Amortization of losses
18.7

 
23.2

 
3.6

 
3.6

 
22.3

 
26.8

Amortization of prior service cost
—

 
—

 
0.2

 
0.2

 
0.2

 
0.2

Settlement loss
—

 
—

 
1.8

 
4.9

 
1.8

 
4.9

Net periodic pension cost
$
5.5

 
9.3

 
16.0

 
18.7

 
21.5

 
28.0

 
 
 
 
 
 
 
 
 
 
 
 
Included in:
 

 
 

 
 

 
 

 
 

 
 

Continuing operations
$
5.5

 
9.3

 
16.0

 
17.6

 
21.5

 
26.9

Discontinued operations
—

 
—

 
—

 
1.1

 
—

 
1.1

Net periodic pension cost
$
5.5

 
9.3

 
16.0

 
18.7

 
21.5

 
28.0
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 September 30,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Interest cost on accumulated postretirement benefit obligations
$
4.7

 
4.2

 
0.7

 
0.7

 
5.4

 
4.9

Return on assets – expected
(4.4
)
 
(5.1
)
 
—

 
—

 
(4.4
)
 
(5.1
)
Amortization of losses
4.7

 
3.7

 
0.6

 
0.8

 
5.3

 
4.5

Amortization of prior service (credit) cost
(1.2
)
 
(1.1
)
 
0.4

 
0.5

 
(0.8
)
 
(0.6
)
Net periodic postretirement cost
$
3.8

 
1.7

 
1.7

 
2.0

 
5.5

 
3.7

 
 
 
 
 
 
 
 
 
 
 
 
Nine months ended September 30,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Service cost
$
—

 
—

 
—

 
0.1

 
—

 
0.1

Interest cost on accumulated postretirement benefit obligations
14.1

 
12.9

 
2.0

 
2.1

 
16.1

 
15.0

Return on assets – expected
(13.1
)
 
(15.4
)
 
—

 
—

 
(13.1
)
 
(15.4
)
Amortization of losses
13.5

 
11.7

 
1.8

 
2.3

 
15.3

 
14.0

Amortization of prior service (credit) cost
(3.5
)
 
(3.4
)
 
1.3

 
1.4

 
(2.2
)
 
(2.0
)
Net periodic postretirement cost
$
11.0

 
5.8

 
5.1

 
5.9

 
16.1

 
11.7