Accumulated Other Comprehensive Loss - Schedule of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 796.5	$ 816.1
Ending Balance	800.9	782.3
Currency Translation
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(233.4)	(246.8)
Other comprehensive income (loss)	2.2	(41.9)
Ending Balance	(231.2)	(288.7)
Accumulated Defined Benefit Plans Adjustment | Defined Benefit Pension Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(214.5)	(202.2)
Other comprehensive income (loss)	3.5	3.0
Ending Balance	(211.0)	(199.2)
Accumulated Defined Benefit Plans Adjustment | OPEB Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(0.3)	0.2
Other comprehensive income (loss)	(0.1)	(0.1)
Ending Balance	(0.4)	0.1
Total Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(448.2)	(448.8)
Other comprehensive income (loss)	5.6	(39.0)
Ending Balance	$ (442.6)	$ (487.8)