Shareholders' Equity (Schedule of Accumulated Other Comprehensive (Loss) Activity) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		$ 669.0	$ 566.7	$ 591.8	$ 535.0
Ending Balance		717.0	585.5	717.0	585.5
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	(0.2)	1.1	1.0	0.5
Other comprehensive (loss) income before reclassifications, net of tax benefit (expense)	[1]	0.3	(0.5)	(0.9)	0.1
Amounts reclassified from accumulated other comprehensive (loss)	[1]	0.0	0.0	0.0	0.0
Net current period other comprehensive income (loss)	[1]	0.3	(0.5)	(0.9)	0.1
Ending Balance	[1]	0.1	0.6	0.1	0.6
Derivative Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	1.2	7.1	0.5	9.5
Other comprehensive (loss) income before reclassifications, net of tax benefit (expense)	[1]	(4.7)	0.7	(1.4)	2.5
Amounts reclassified from accumulated other comprehensive (loss)	[1]	(1.0)	(2.6)	(3.6)	(6.8)
Net current period other comprehensive income (loss)	[1]	(5.7)	(1.9)	(5.0)	(4.3)
Ending Balance	[1]	(4.5)	5.2	(4.5)	5.2
Pension And Postretirement Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	(107.5)	(110.0)	(106.2)	(110.1)
Other comprehensive (loss) income before reclassifications, net of tax benefit (expense)	[1]	(0.4)	(0.1)	(0.4)	0.2
Amounts reclassified from accumulated other comprehensive (loss)	[1]	(0.6)	(0.1)	(1.9)	(0.3)
Net current period other comprehensive income (loss)	[1]	(1.0)	(0.2)	(2.3)	(0.1)
Ending Balance	[1]	(108.5)	(110.2)	(108.5)	(110.2)
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	(106.5)	(101.8)	(104.7)	(100.1)
Other comprehensive (loss) income before reclassifications, net of tax benefit (expense)	[1]	(4.8)	0.1	(2.7)	2.8
Amounts reclassified from accumulated other comprehensive (loss)	[1]	(1.6)	(2.7)	(5.5)	(7.1)
Net current period other comprehensive income (loss)	[1]	(6.4)	(2.6)	(8.2)	(4.3)
Ending Balance	[1]	$ (112.9)	$ (104.4)	$ (112.9)	$ (104.4)

[1] Amounts are net of tax.