Pension and Other Postretirement Benefit Plans (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Pension [Member]
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Service Cost		$ 2.4	$ 2.7
Interest Cost	[1]	6.7	6.1
Expected Return on Plan Assets	[1]	(10.4)	(10.8)
Amortization of Prior Service Credits	[1]	0.0	0.0
Amortization of Net Loss	[1]	3.2	4.7
Net Periodic Benefit Cost (Credit)		1.9	2.7
Employer Contributions to Defined Benefit Plans		0.0	10.3
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		0.0
Other Postretirement [Member]
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Service Cost		0.8	0.9
Interest Cost	[1]	1.1	1.1
Expected Return on Plan Assets	[1]	(2.4)	(2.4)
Amortization of Prior Service Credits	[1]	(1.9)	(1.9)
Amortization of Net Loss	[1]	0.1	0.7
Net Periodic Benefit Cost (Credit)		(2.3)	(1.6)
Employer Contributions to Defined Benefit Plans		0.0	$ 0.0
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year		$ 0.0

[1] These components of net periodic benefit cost (credit) are included in the line item “Other” under Other Income (Expense) on the Consolidated Statement of Income.