Derivatives - Schedule of Changes in Fair Value of Derivative Assets and Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 789	$ 2
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Instruments Designated As Hedging Instruments Interest Income	(81)	249
Derivative, Net Hedge Ineffectiveness Gain (Loss)	0	78
Forward Contracts [Member]
Derivative [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	(62)	112
Foreign Exchange [Member]
Derivative [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	$ (3)	$ 2