Other Real Estate Owned, Net - Summary of Properties Included in Other Real Estate Owned (OREO) (Detail) $ in Thousands	Jun. 30, 2018 USD ($) Property	Dec. 31, 2017 USD ($) Property
Real Estate Properties [Line Items]
No. of Properties | Property	26	29
Carrying Value | $	$ 3,501	$ 4,284	[1]
Residential
Real Estate Properties [Line Items]
No. of Properties | Property	3	5
Carrying Value | $	$ 945	$ 443
Land
Real Estate Properties [Line Items]
No. of Properties | Property	20	20
Carrying Value | $	$ 2,020	$ 3,223
Commercial properties
Real Estate Properties [Line Items]
No. of Properties | Property	3	4
Carrying Value | $	$ 536	$ 618

[1] Derived from audited December 31, 2017 Consolidated Financial Statements.