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Retirement Benefits (Details 14) $ in Millions | Dec. 31, 2018 USD ($)
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Pension Benefits [Member] |
Defined Benefit Plan Expected Future Benefit Payments [Abstract] |
2019 | $ 186.6
2020 | 180.7
2021 | 177.9
2022 | 176.1
2023 | 173.9
2024-2028 | 825.0
Other Postretirement Benefits [Member] |
Defined Benefit Plan Expected Future Benefit Payments [Abstract] |
2019 | 40.6
2020 | 38.2
2021 | 35.6
2022 | 33.1
2023 | 30.8
2024-2028 | 123.9
Medicare Part D Subsidy [Abstract] |
2019 | 0.6
2020 | 0.6
2021 | 0.6
2022 | 0.5
2023 | 0.5
2024-2028 | $ 1.9

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