Derivative Financial Assets and Liabilities Measured at Fair Value on Recurring Basis for Continuing Operations (Parenthetical) (Detail) - Not Designated as Hedging Instrument - Foreign Exchange Swaps - Fair Value, Measurements, Recurring - Less Than Six Months - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative notional volume, amount after offsetting swaps	$ 1,136.0	$ 468.2
Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, amount after offsetting swaps	2.0	2.4
Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, amount after offsetting swaps	$ 3.8	$ 0.3