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, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Foreign Currency Exchange Contracts 1
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	$ 1,146	$ (207)	$ 1,735	$ 295
Foreign Currency Exchange Contracts 1 | Salaries and employee benefits
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	297	274	472	532
Foreign Currency Exchange Contracts 1 | Other (expense) income
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
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	160	(36)	240	(190)
Foreign Currency Exchange Contracts 2 | General and administrative expenses
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	27	46	41	69
Foreign Currency Exchange Contracts 2 | Other (expense) income
Derivative [Line Items]
Amount of Gain or (Loss) Recognized - Ineffective Portion and Amount Excluded from Effectiveness Testing	0	0	0	0
Cash Flow Hedging | Interest rate swap agreements
Derivative [Line Items]
Gain or (Loss) Recognized in OCI- Effective Portion	14	0	19	0
Cash Flow Hedging | Interest rate swap agreements | Interest expense
Derivative [Line Items]
Gain or (Loss) Reclassified from OCI into Income - Effective Portion	33	0	110	0
Cash Flow Hedging | Interest rate swap agreements | Other (expense) income
Derivative [Line Items]
Amount of Gain or (Loss) Recognized - Ineffective Portion and Amount Excluded from Effectiveness Testing	$ 0	$ 0	$ 0	$ 0