Pension and Postretirement Plans - Benefit Obligation and Funded Status (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		$ 400.9
Fair value of plan assets at end of period		274.6	$ 400.9
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of period		433.7	439.5
Service cost		0.0	0.0	$ 0.0
Interest cost		18.8	22.0	16.3
Plan Amendment		0.0	0.1
Actuarial (gain) loss	[1],[2]	(13.0)	8.8
Benefits paid		(28.3)	(36.7)
Settlements	[3]	(112.9)	0.0
Other		0.0	0.0
Benefit obligation at end of period		298.3	433.7	439.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		397.8	390.6
Actual return (loss) on plan assets		12.4	41.7
Employer contributions		2.7	2.2
Benefits paid		(28.3)	(36.7)
Settlements	[3]	(112.9)	0.0
Fair value of plan assets at end of period		271.7	397.8	390.6
Unfunded status		(26.6)	(35.9)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of period		102.1	102.4
Service cost		0.4	0.5	0.8
Interest cost		5.0	5.2	4.2
Plan Amendment		0.0	0.0
Actuarial (gain) loss	[1],[2]	(6.2)	1.1
Benefits paid		(8.8)	(9.1)
Settlements	[3]	0.0	0.0
Other		1.9	2.0
Benefit obligation at end of period		94.4	102.1	102.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		3.1	3.2
Actual return (loss) on plan assets		0.0	0.0
Employer contributions		6.4	6.9
Benefits paid		(6.6)	(7.0)
Settlements	[3]	0.0	0.0
Fair value of plan assets at end of period		2.9	3.1	$ 3.2
Unfunded status		$ (91.5)	$ (99.0)

[1] The actuarial (gain) recorded for the year ended December 31, 2024 for the pension plans was primarily driven by an increase in the discount rate. The actuarial loss recorded during the year ended December 31, 2023 for the pension plans was primarily driven by a decrease in the discount rate.

[2] The actuarial (gain) recorded for the year ended December 31, 2024 for the postretirement plans was primarily driven by an increase in the discount rate. The actuarial loss recorded for the year ended December 31, 2023 for the postretirement plans was primarily driven by a decrease in the discount rate.

[3] Group annuity contracts and participant elections to take lump sum payments that exceeded the settlement accounting threshold and have been categorized as settlements.