Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive loss, net of tax	$ (34.5)	$ (30.7)
Net current period other comprehensive income ending balance	(3.8)	2.6	$ 9.3
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	0.1	0.1	(1.6)
Defined Benefit Pension Plan Adjustments
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive loss, net of tax	(34.5)	(30.7)	(33.3)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(3.6)	2.8
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(0.3)	(0.2)
Net current period other comprehensive income ending balance		2.6
Pension Benefit Plans \| Defined Benefit Pension Plan Adjustments
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive loss, net of tax	(47.8)	(42.0)	(46.5)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(6.0)	4.5
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.1	0.1
Net current period other comprehensive income ending balance	(5.9)	4.6
Other Postretirement Benefits Plan [Member]
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive loss, net of tax	13.4	11.3	$ 13.3
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	2.4	(1.7)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(0.4)	(0.3)
Net current period other comprehensive income ending balance	$ 2.1	$ (2.0)

Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

- Definition

Amount after tax, before reclassification adjustments of other comprehensive income (loss).

+ References + Details

- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

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+ Details

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

+ References + Details

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