Employee Benefit Plans and Other Postretirement Benefit Plans Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Liability, Defined Benefit Pension Plan, Noncurrent	$ 130.4	$ 141.2
Liability, Other Postretirement Defined Benefit Plan, Noncurrent	552.8	$ 556.7
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	1.0
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 17.0