Accumulated Other Comprehensive Loss (Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 892.9
Ending balance	910.3
Foreign Currency
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(7.7)	$ (12.4)
Other comprehensive (loss) income before reclassifications	(8.9)	2.0
Amounts reclassified from accumulated other comprehensive income (net of tax $(1.9) and $(1.3))	0.0	0.0
Net current-period other comprehensive (loss) income	(8.9)	2.0
Ending balance	(16.6)	(10.4)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(242.9)	(227.9)
Other comprehensive (loss) income before reclassifications	0.0	0.0
Amounts reclassified from accumulated other comprehensive income (net of tax $(1.9) and $(1.3))	5.5	3.7
Net current-period other comprehensive (loss) income	5.5	3.7
Ending balance	(237.4)	(224.2)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(250.6)	(240.3)
Other comprehensive (loss) income before reclassifications	(8.9)	2.0
Amounts reclassified from accumulated other comprehensive income (net of tax $(1.9) and $(1.3))	5.5	3.7
Net current-period other comprehensive (loss) income	(3.4)	5.7
Ending balance	$ (254.0)	$ (234.6)