Summary of Information about Contract Balance with Customers (Detail) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Contract With Customer Asset And Liability [Abstract]
Receivables, net		$ 1,652.1	$ 1,696.7	$ 1,515.1
Contract assets	[1]	19.5
Contract liabilities	[2]	$ 29.4	$ 33.0

[1] Included in other current assets.

[2] Included in other current and other non-current liabilities.