Securities - Aggregate Amortized Costs and Fair Values of Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 80,214	$ 83,804
Gross Unrealized Gains	733	118
Gross Unrealized (Losses)	(199)	(1,690)
Fair Value	80,748	82,232	[1]
US Government Agencies and Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50,324	51,126
Gross Unrealized Gains	286	35
Gross Unrealized (Losses)	(192)	(1,279)
Fair Value	50,418	49,882
State and Municipal Obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,717	20,484
Gross Unrealized Gains	382	60
Gross Unrealized (Losses)	(3)	(327)
Fair Value	17,096	20,217
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,173	12,194
Gross Unrealized Gains	65	23
Gross Unrealized (Losses)	(4)	(84)
Fair Value	$ 13,234	$ 12,133

[1] Derived from audited December 31, 2018 Consolidated Financial Statements.