Other Real Estate Owned, net - Carrying Value of Properties Included in Other Real Estate Owned, Net (Detail) $ in Thousands	Dec. 31, 2018 USD ($) Property	Dec. 31, 2017 USD ($) Property
Real Estate Properties [Line Items]
No. of Properties | Property	26	29
Carrying Value | $	$ 3,597	$ 4,284
Residential
Real Estate Properties [Line Items]
No. of Properties | Property	6	5
Carrying Value | $	$ 1,339	$ 443
Land
Real Estate Properties [Line Items]
No. of Properties | Property	17	20
Carrying Value | $	$ 1,741	$ 3,223
Commercial
Real Estate Properties [Line Items]
No. of Properties | Property	3	4
Carrying Value | $	$ 517	$ 618