Changes in Accumulated Other Comprehensive Loss (Classification Of Accumulated Other Comprehensive Income Reflected On Consolidated Balance Sheets) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive loss, beginning balance	$ (503.3)
Other comprehensive income (loss) before reclassifications	12.8
Amounts reclassified from accumulated other comprehensive loss	2.7
Net period other comprehensive income (loss)	15.5
Accumulated other comprehensive loss, ending balance	(487.8)
Deferred tax assets, other comprehensive loss	107.3		$ 106.6
Reclassification out of Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss	2.7	$ 3.3
Defined Benefit Pension and Postretirement Items
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive loss, beginning balance	(271.9)
Net period other comprehensive income (loss)	2.7
Accumulated other comprehensive loss, ending balance	(269.2)
Currency Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated other comprehensive loss, beginning balance	(231.4)
Other comprehensive income (loss) before reclassifications	12.8
Net period other comprehensive income (loss)	12.8
Accumulated other comprehensive loss, ending balance	$ (218.6)