|
Retirement Benefits (Details) (USD $)
In Millions, unless otherwise specified
|
3 Months Ended |
|
Mar. 31, 2015
|
Mar. 31, 2014
|
| Pension Contributions |
$ 20 |
|
| Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year |
30 |
|
| Pension And Other Postretirement Benefit Contributions, Estimated Future Discretionary Contributions |
270 |
|
| Pension Plans, Defined Benefit [Member] |
|
|
| Defined Benefit Plan, Service Cost |
77.0 |
62.7 |
| Defined Benefit Plan, Interest Cost |
117.1 |
119.2 |
| Defined Benefit Plan, Expected Return on Plan Assets |
(191.8) |
(189.3) |
| Defined Benefit Plan, Amortization of Prior Service Cost (Credit) |
2.5 |
0.9 |
| Defined Benefit Plan, Actuarial Gain (Loss) |
92.4 |
69.1 |
| Defined Benefit Plan, Net Periodic Benefit Cost, Total |
97.2 |
62.6 |
| Other Postretirement Benefit Plans, Defined Benefit [Member] |
|
|
| Defined Benefit Plan, Service Cost |
9.8 |
11.3 |
| Defined Benefit Plan, Interest Cost |
15.4 |
21.2 |
| Defined Benefit Plan, Expected Return on Plan Assets |
(37.1) |
(36.0) |
| Defined Benefit Plan, Amortization of Prior Service Cost (Credit) |
(21.6) |
(7.3) |
| Defined Benefit Plan, Actuarial Gain (Loss) |
9.4 |
5.1 |
| Defined Benefit Plan, Net Periodic Benefit Cost, Total |
$ (24.1) |
$ (5.7) |