Disclosures About Fair Value of Financial Instruments - Statement of Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis (Detail) - Significant Unobservable Inputs (Level 3) - Residential Mortgage Loan Commitments - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning	$ 73	$ 87	$ 45	$ 43
Issuances	157	71	230	158
Settlements	(73)	(87)	(118)	(130)
Balance at ending	$ 157	$ 71	$ 157	$ 71