Employee Benefit Plans (Accumulated Other Comprehensive Income (Loss) Pretax Amounts Not Yet Reclassified in Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized actuarial (gain) loss	$ (59.9)	$ 33.9
Unrecognized prior service cost (credit)	6.6	(1.4)
Total	(53.3)	32.5
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized actuarial (gain) loss	21.7	5.7
Unrecognized prior service cost (credit)	(3.7)	0.6
Total	$ 18.0	$ 6.3