|
Retirement Benefits - Retirement Cost (Details) (USD $)
In Millions, unless otherwise specified
|
3 Months Ended |
9 Months Ended |
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
|
US Plans [Member]
|
|
|
|
|
| Net periodic pension cost (credit) [Line Items] |
|
|
|
|
| Service cost |
$ 0 |
$ 0 |
$ 0 |
$ 0 |
| Interest cost |
11.0 |
11.6 |
33.0 |
34.7 |
| Return on assets - expected |
(14.9) |
(16.2) |
(44.9) |
(48.7) |
| Amortization of losses |
9.7 |
7.0 |
29.4 |
21.0 |
| Amortization of prior service cost |
0 |
0 |
0 |
0 |
| Settlement loss |
1.0 |
0 |
5.0 |
0 |
| Net periodic pension cost |
6.8 |
2.4 |
22.5 |
7.0 |
|
Non-US Plans [Member]
|
|
|
|
|
| Net periodic pension cost (credit) [Line Items] |
|
|
|
|
| Service cost |
2.8 |
2.5 |
8.2 |
7.8 |
| Interest cost |
5.0 |
4.3 |
13.9 |
12.9 |
| Return on assets - expected |
(3.0) |
(3.0) |
(9.1) |
(9.1) |
| Amortization of losses |
0.9 |
0.5 |
3.0 |
2.0 |
| Amortization of prior service cost |
0.6 |
0.4 |
1.4 |
1.2 |
| Settlement loss |
1.5 |
0.7 |
2.6 |
1.7 |
| Net periodic pension cost |
7.8 |
5.4 |
20.0 |
16.5 |
|
Umwa Plans Postretirement Medical [Member]
|
|
|
|
|
| Net periodic pension cost (credit) [Line Items] |
|
|
|
|
| Service cost |
0 |
0 |
0 |
0 |
| Interest cost |
5.6 |
5.9 |
16.8 |
17.9 |
| Return on assets - expected |
(5.3) |
(6.4) |
(15.9) |
(19.2) |
| Amortization of losses |
5.1 |
3.8 |
15.6 |
11.3 |
| Amortization of prior service cost |
0 |
0 |
0 |
0 |
| Net periodic pension cost |
5.4 |
3.3 |
16.5 |
10.0 |
|
Black Lung And Other Plans Postretirement Medical [Member]
|
|
|
|
|
| Net periodic pension cost (credit) [Line Items] |
|
|
|
|
| Service cost |
0.2 |
0 |
0.3 |
0 |
| Interest cost |
0.7 |
0.7 |
2.2 |
2.1 |
| Return on assets - expected |
0 |
0 |
0 |
0 |
| Amortization of losses |
0.4 |
0.1 |
1.0 |
0.3 |
| Amortization of prior service cost |
0.5 |
0.5 |
1.5 |
1.5 |
| Net periodic pension cost |
1.8 |
1.3 |
5.0 |
3.9 |
|
Pension plan [Member]
|
|
|
|
|
| Net periodic pension cost (credit) [Line Items] |
|
|
|
|
| Service cost |
2.8 |
2.5 |
8.2 |
7.8 |
| Interest cost |
16.0 |
15.9 |
46.9 |
47.6 |
| Return on assets - expected |
(17.9) |
(19.2) |
(54.0) |
(57.8) |
| Amortization of losses |
10.6 |
7.5 |
32.4 |
23.0 |
| Amortization of prior service cost |
0.6 |
0.4 |
1.4 |
1.2 |
| Settlement loss |
2.5 |
0.7 |
7.6 |
1.7 |
| Net periodic pension cost |
14.6 |
7.8 |
42.5 |
23.5 |
|
Retirement benefits other than pension [Member]
|
|
|
|
|
| Net periodic pension cost (credit) [Line Items] |
|
|
|
|
| Service cost |
0.2 |
0 |
0.3 |
0 |
| Interest cost |
6.3 |
6.6 |
19.0 |
20.0 |
| Return on assets - expected |
(5.3) |
(6.4) |
(15.9) |
(19.2) |
| Amortization of losses |
5.5 |
3.9 |
16.6 |
11.6 |
| Amortization of prior service cost |
0.5 |
0.5 |
1.5 |
1.5 |
| Net periodic pension cost |
$ 7.2 |
$ 4.6 |
$ 21.5 |
$ 13.9 |