Derivative Financial Instruments - Summary of (Gain) Loss Reclassified From Accumulated Other Comprehensive Loss Earnings For Derivatives (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments Gain Loss [Line Items]
(Gain) loss on derivative hedging instruments	$ 16,950	$ 1,884
Cross Currency Swap Agreements [Member] | Designated as Hedging Instrument [Member] | Other Non-operating (Income) Expense, Net [Member]
Derivative Instruments Gain Loss [Line Items]
(Gain) loss on derivative hedging instruments	13,242	995
Cross Currency Swap Agreements [Member] | Not Designated as Hedging Instrument [Member] | Other Non-operating (Income) Expense, Net [Member]
Derivative Instruments Gain Loss [Line Items]
(Gain) loss on derivative hedging instruments	$ 3,708	$ 889