Derivatives and Hedging Activities - Summary of Effect of Derivative Instruments on Income Statement (Detail) - Derivatives Not Designated as Hedging Instruments [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) on derivative financial instruments	$ 495	$ 3	$ (162)
Interest Rate Product [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss) on derivative financial instruments	$ 495	$ 3	$ (162)