Fair Value Measurements - Financial Assets and Financial Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale, fair value	$ 100,717	$ 81,581
Items measured on a recurring basis | U.S. Agency Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale, fair value	100,717	81,581
Items measured on a recurring basis | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments	9,655	8,700
Items measured on a recurring basis | Interest rate swap asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap asset	1,722
Items measured on a recurring basis | Interest rate swap liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liability	(1,813)
Items measured on a non-recurring basis | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	1,381	8,186
Items measured on a non-recurring basis | Loans measured for impairment based on the fair value of the underlying collateral
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	11,639	16,496
Level 1 Inputs | Items measured on a recurring basis | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments	9,655	8,700
Level 2 Inputs | Items measured on a recurring basis | U.S. Agency Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale, fair value	100,717	81,581
Level 2 Inputs | Items measured on a recurring basis | Interest rate swap asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap asset	1,722
Level 2 Inputs | Items measured on a recurring basis | Interest rate swap liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liability	(1,813)
Level 3 Inputs | Items measured on a non-recurring basis | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	1,381	8,186
Level 3 Inputs | Items measured on a non-recurring basis | Loans measured for impairment based on the fair value of the underlying collateral
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	$ 11,639	$ 16,496