Changes In Equity And Comprehensive Income (Classification Of Accumulated Other Comprehensive Income Reflected On Consolidated Balance Sheets) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance	$ (447.6)
Other comprehensive income (loss) before reclassifications	(0.1)
Amounts reclassified from accumulated other comprehensive income	2.2
Net current-period othre comprehensive income (loss)	2.1
Accumulated other comprehensive loss, ending balance	(445.5)
Deferred tax assets, other comprehensive loss	$ 123.0	$ 122.2
Document Period End Date	Mar. 31, 2019
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance	$ (318.3)
Other comprehensive income (loss) before reclassifications	0.7
Net current-period othre comprehensive income (loss)	2.9
Accumulated other comprehensive loss, ending balance	(315.4)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance	(129.3)
Other comprehensive income (loss) before reclassifications	(0.8)
Amounts reclassified from accumulated other comprehensive income	0.0
Net current-period othre comprehensive income (loss)	(0.8)
Accumulated other comprehensive loss, ending balance	$ (130.1)