Derivatives - Schedule of Changes in Fair Value of Derivative Assets and Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 0	$ (13)	$ 789	$ (49)
Derivative, Net Hedge Ineffectiveness Gain (Loss)	221	0
Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)			(432)	0
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Instruments Designated As Hedging Instruments Interest Income	(193)	35	(424)	420
Derivative, Net Hedge Ineffectiveness Gain (Loss)	0	9	10	82
Forward Contracts [Member]
Derivative [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	125	61	96	(34)
Foreign Exchange [Member]
Derivative [Line Items]
Derivative, Net Hedge Ineffectiveness Gain (Loss)	$ 2	$ 2	$ 10	$ 3