Retirement and Postretirement Plans - Schedule of Reconciliation of Plans Benefit Obligations, Plan Assets and Funded Status and Amounts Recognized (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations at beginning of period	$ 2,257.1	$ 2,553.5
Service cost	1.1	1.1	$ 1.0
Interest cost	46.8	40.2	63.6
Plan amendments	0.7
Actuarial (gain) loss	(399.7)	(82.9)
ESOP transfer	3.0	2.7
Benefit payments	(129.7)	(257.5)
Benefit obligation at end of period	1,779.3	2,257.1	2,553.5
Fair value of plan assets at beginning of period	2,152.4	2,221.8
Actual return on plan assets	(467.3)	181.2
Employer contributions	4.1	4.2
ESOP transfer	3.0	2.7
Benefit payments	(129.7)	(257.5)
Fair value of plan assets at end of period	1,562.5	2,152.4	2,221.8
Amounts recognized in Consolidated Balance Sheets
Current liabilities	(4.0)	(4.0)
Noncurrent liabilities	(212.8)	(100.7)
Funded status	(216.8)	(104.7)
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations at beginning of period	27.2	29.6
Interest cost	0.5	0.4	0.6
Actuarial (gain) loss	(4.9)	(1.1)
Benefit payments	(1.5)	(1.7)
Benefit obligation at end of period	21.3	27.2	$ 29.6
Employer contributions	1.5	1.7
Benefit payments	(1.5)	(1.7)
Amounts recognized in Consolidated Balance Sheets
Current liabilities	(2.6)	(2.8)
Noncurrent liabilities	(18.7)	(24.4)
Funded status	$ (21.3)	$ (27.2)