Reserve for Unfunded Commitments - Summary of Activity in Reserve for Unfunded Commitments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Balance at beginning of period	$ 2,883	$ 2,125	$ 2,475	$ 2,145
Provision for losses - unfunded commitments	25	(40)	433	(60)
Balance at end of period	$ 2,908	$ 2,085	$ 2,908	$ 2,085