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) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Foreign Currency Exchange Contracts 1 [Member]
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	$ (207)	$ (395)	$ 295	$ 77
Foreign Currency Exchange Contracts 1 [Member] | Salaries and Employee Benefits [Member]
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	274	(164)	532	(315)
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	0	0
Foreign Currency Exchange Contracts 2 [Member]
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	(36)	(70)	(190)	150
Foreign Currency Exchange Contracts 2 [Member] | General and Administrative Expenses [Member]
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	46	(31)	69	(47)
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	$ 0	$ 0