Shareholders' Equity (Schedule of Accumulated Other Comprehensive (Loss) Activity) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		$ 566.7	$ 527.8	$ 535.0	$ 519.7
Ending Balance		585.5	521.2	585.5	521.2
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		1.1	2.1	0.5	2.3
Other comprehensive (loss) income before reclassifications, net of tax (expense)		(0.5)	(2.1)	0.1	(2.3)
Amounts reclassified from accumulated other comprehensive (loss)		0.0	0.0	0.0	0.0
Net current period other comprehensive (loss)		(0.5)	(2.1)	0.1	(2.3)
Ending Balance		0.6	0.0	0.6	0.0
Derivative (Loss) Gain [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	7.1	4.5	9.5	(9.1)
Other comprehensive (loss) income before reclassifications, net of tax (expense)	[1]	0.7	4.9	2.5	21.3
Amounts reclassified from accumulated other comprehensive (loss)	[1]	(2.6)	0.0	(6.8)	(2.8)
Net current period other comprehensive (loss)	[1]	(1.9)	4.9	(4.3)	18.5
Ending Balance	[1]	5.2	9.4	5.2	9.4
Pension And Postretirement Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	(110.0)	(102.1)	(110.1)	(102.8)
Other comprehensive (loss) income before reclassifications, net of tax (expense)	[1]	(0.1)	0.0	0.2	0.3
Amounts reclassified from accumulated other comprehensive (loss)	[1]	(0.1)	0.2	(0.3)	0.6
Net current period other comprehensive (loss)	[1]	(0.2)	0.2	(0.1)	0.9
Ending Balance	[1]	(110.2)	(101.9)	(110.2)	(101.9)
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	[1]	(101.8)	(95.5)	(100.1)	(109.6)
Other comprehensive (loss) income before reclassifications, net of tax (expense)	[1]	0.1	2.8	2.8	19.3
Amounts reclassified from accumulated other comprehensive (loss)	[1]	(2.7)	0.2	(7.1)	(2.2)
Net current period other comprehensive (loss)	[1]	(2.6)	3.0	(4.3)	17.1
Ending Balance	[1]	$ (104.4)	$ (92.5)	$ (104.4)	$ (92.5)

[1] Amounts are net of tax.