Premises and Equipment, Net - Components of Premises and Equipment, Net of Accumulated Depreciation, Included in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 38,118	$ 35,527
Less accumulated depreciation	(19,949)	(18,064)
Premises and equipment, net	18,169	17,463
Land and Improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	4,639	4,639
Buildings and Improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	20,261	19,257
Furniture and Equipment
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 13,218	$ 11,631

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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