Summary of Significant Accounting Policies - Summary of Other (Income) Expense, Net (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Other expense	$ 52.2	$ 43.8	$ 57.2
Other income	(27.6)	(12.2)	(61.3)
Other (income) expense, net	$ 24.6	$ 31.6	$ (4.1)