Derivatives and Hedging Instruments - Summary of Effects of Derivatives on Cash Flow Hedging Relationships in Company's Statements of Income, Derivatives Designated as Hedging Instruments (Detail) - Cash Flow Hedging [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Foreign Currency Exchange Contracts 1 [Member]
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	$ 1,404	$ (248)
Foreign Currency Exchange Contracts 1 [Member] | Salaries and employee benefits [Member]
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	755	(472)
Foreign Currency Exchange Contracts 1 [Member] | Other (expense) income [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized - Ineffective Portion and Amount Excluded from Effectiveness Testing	0	0
Foreign Currency Exchange Contracts 2 [Member]
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	(5)	88
Foreign Currency Exchange Contracts 2 [Member] | General and administrative expenses [Member]
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	105	(74)
Foreign Currency Exchange Contracts 2 [Member] | Other (expense) income [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized - Ineffective Portion and Amount Excluded from Effectiveness Testing	0	0
Interest Rate Swap [Member]
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	(131)	0
Interest Rate Swap [Member] | Interest Expense [Member]
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	0	0
Interest Rate Swap [Member] | Other (expense) income [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized - Ineffective Portion and Amount Excluded from Effectiveness Testing	$ 0	$ 0