Changes In Equity And Accumulated Other Comprehensive Loss (Classification Of Accumulated Other Comprehensive Income Reflected On Consolidated Balance Sheets) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance	$ (483.7)
Other comprehensive income (loss) before reclassifications	13.2
Amounts reclassified from accumulated other comprehensive income	10.4
Net current-period othre comprehensive income (loss)	23.6
Accumulated other comprehensive loss, ending balance	(460.1)
Deferred tax assets, other comprehensive loss	138.5	$ 135.4
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance	(366.0)
Other comprehensive income (loss) before reclassifications	0.0
Net current-period othre comprehensive income (loss)	10.4
Accumulated other comprehensive loss, ending balance	(355.6)
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance	(117.7)
Other comprehensive income (loss) before reclassifications	13.2
Amounts reclassified from accumulated other comprehensive income	0.0
Net current-period othre comprehensive income (loss)	13.2
Accumulated other comprehensive loss, ending balance	$ (104.5)