Revenue From Contracts With Customers - Allowance for Doubtful Accounts (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable Classified [Abstract]
Allowance for doubtful accounts, beginning of period	$ 35.4	$ 17.4	$ 14.0
Charged to costs and expenses	5.0	10.6	6.0
Write-offs	(3.2)	(1.7)	(1.2)
Foreign exchange and other	3.1	9.1	1.4
Allowance for doubtful accounts, end of period	$ 40.3	$ 35.4	$ 17.4