Premises and Equipment - Schedule of Right-of-use Asset and Lease Obligations by Type of Property (Detail) $ in Thousands	Dec. 31, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Right-of-Use Asset	$ 4,153
Lease Liability	$ 4,112
Weighted Average Lease Term in Years	16 years
Weighted Average Discount Rate	2.95%
Land and Building Leases [Member]
Property, Plant and Equipment [Line Items]
Right-of-Use Asset	$ 4,153
Lease Liability	$ 4,112
Weighted Average Lease Term in Years	16 years
Weighted Average Discount Rate	2.95%