Financial Instruments - Derivative Instruments Which Were Not Designated as Hedging Instruments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Foreign Currency Contracts [Member] | Other (income) expense, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) on derivative	$ 1,999	$ (10,057)
Fair Value of Derivatives Not Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) on derivative	14,505	(10,057)
Deal Contingent Swaps [Member] | Fair Value of Derivatives Not Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member] | Other Income Expense Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) on derivative	12,154	0
Deal Contingent Swaps [Member] | Fair Value of Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) on derivative	$ 352	$ 0