Defined Benefit and Postretirement Benefits Contributions by Plan Type (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	$ 21.4
Defined Benefit Plan, Plan Assets, Contributions by Employer	1.6
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	2.5
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 1.5