Retirement Benefits (Details 14) $ in Millions	Dec. 31, 2018 USD ($)
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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