Accumulated Other Comprehensive Loss (Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 1,126.5
Retained Earnings	945.5		$ 850.3
Ending balance	1,235.6
Amounts reclassified from accumulated other comprehensive income, tax	(1.4)	$ (2.3)
Foreign Currency
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(5.0)	(5.1)
Other comprehensive income before reclassifications	2.1	1.4
Amounts reclassified from accumulated other comprehensive income (net of tax)
Net current-period other comprehensive income	2.1	1.4
Ending balance	(2.9)	(3.7)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(175.5)	(241.6)
Other comprehensive income before reclassifications
Amounts reclassified from accumulated other comprehensive income (net of tax)	4.4	6.6
Net current-period other comprehensive income	4.4	6.6
Ending balance	(171.1)	(235.0)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(180.5)	(246.7)
Other comprehensive income before reclassifications	2.1	1.4
Amounts reclassified from accumulated other comprehensive income (net of tax)	4.4	6.6
Net current-period other comprehensive income	6.5	8.0
Ending balance	$ (174.0)	$ (238.7)