Pension and Other Post-Retirement Benefits - Expected Benefit Plan Payments (Details) $ in Millions	Dec. 31, 2021 USD ($)
Qualified Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
2018	$ 28.3
2019	28.2
2020	29.6
2021	28.7
2022	28.0
Years 2027-2031	135.2
Total	278.0
Nonqualified Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
2018	16.5
2019	2.8
2020	2.5
2021	2.5
2022	2.4
Years 2027-2031	12.8
Total	39.5
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2018	2.0
2019	1.9
2020	1.8
2021	1.6
2022	1.5
Years 2027-2031	5.9
Total	$ 14.7