Shareholders' Equity (Schedule of Accumulated Other Comprehensive (Loss) Activity) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 519.7	$ 450.9
Ending Balance	537.6	473.6
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	2.3	2.3
Other comprehensive income before reclassifications, net of tax (expense)	0.7	0.6
Amounts reclassified from accumulated other comprehensive (loss)	0.0	0.0
Net current period other comprehensive income	0.7	0.6
Ending Balance	3.0	2.9
Derivative (Loss) Gain [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(9.1)	(19.0)
Other comprehensive income before reclassifications, net of tax (expense)	12.3	5.3
Amounts reclassified from accumulated other comprehensive (loss)	(1.7)	(1.5)
Net current period other comprehensive income	10.6	3.8
Ending Balance	1.5	(15.2)
Pension And Postretirement Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(102.8)	(92.6)
Other comprehensive income before reclassifications, net of tax (expense)	0.5	0.0
Amounts reclassified from accumulated other comprehensive (loss)	0.1	0.2
Net current period other comprehensive income	0.6	0.2
Ending Balance	(102.2)	(92.4)
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(109.6)	(109.3)
Other comprehensive income before reclassifications, net of tax (expense)	13.5	5.9
Amounts reclassified from accumulated other comprehensive (loss)	(1.6)	(1.3)
Net current period other comprehensive income	11.9	4.6
Ending Balance	$ (97.7)	$ (104.7)