Goodwill - Summary of Goodwill (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Goodwill [Line Items]
Gross cost, beginning balance	$ 599.5
Accumulated impairment losses, beginning balance	(236.5)
Net book amount, beginning balance	363.0
Exchange effect	(1.8)
Exchange effect	0.0
Gross cost, ending balance	597.7
Accumulated impairment losses, ending balance	(236.5)
Net book amount, ending balance	$ 361.2