Fair Value Measurements - Financial Assets and Financial Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for sale, at fair value	$ 150,960	$ 100,717
Other real estate owned	264	1,381
Items measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for sale, at fair value	150,960	100,717
Equity investments	10,136	9,655
Interest rate swap asset	10,141	1,722
Interest rate swap liability	(10,708)	(1,813)
Items measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	264
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]
Debt securities, available-for sale, at fair value		11,639
Fair value	8,794	1,381
Level 1 Inputs | Items measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for sale, at fair value	0	0
Equity investments	10,136	9,655
Interest rate swap asset	0	0
Interest rate swap liability	0	0
Level 1 Inputs | Items measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	0
Level 1 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]
Debt securities, available-for sale, at fair value		0
Fair value	0	0
Level 2 Inputs | Items measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for sale, at fair value	150,935	100,717
Equity investments	0	0
Interest rate swap asset	10,141	1,722
Interest rate swap liability	(10,708)	(1,813)
Level 2 Inputs | Items measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	0
Level 2 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]
Debt securities, available-for sale, at fair value		0
Fair value	0	0
Level 3 Inputs | Items measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for sale, at fair value	25	0
Equity investments	0	0
Interest rate swap asset	0	0
Interest rate swap liability	0	0
Level 3 Inputs | Items measured on a non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	264
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]
Debt securities, available-for sale, at fair value		11,639
Fair value	$ 8,794	$ 1,381