Derivatives and Hedging Activities - Summary of Fair Values of Derivative Instruments on Balance Sheets (Detail) - Derivatives Not Designated as Hedging Instruments [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	$ 5,596	$ 1,893
Total Liability Derivatives	5,199	1,991
Interest Rate Product [Member]
Derivatives, Fair Value [Line Items]
Total Asset Derivatives	5,596	1,893
Total Liability Derivatives	$ 5,199	$ 1,991