Fair Value Measurements - Summary of Carrying Amounts and Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Financial assets
Cash and due from banks	$ 140,610	$ 114,342	$ 61,320	$ 78,705
Securities available for sale	34,344	28,555
Loans, net	951,928	940,944
Accrued interest receivable	3,247	3,398
Financial liabilities
Deposits	1,029,353	991,631
Other borrowings	22,539	10,032
Subordinated debt	5,103	5,112
Accrued interest payable	376	400
Carrying Amount [Member]
Financial assets
Cash and due from banks	140,610	114,342
Securities available for sale	34,344	28,555
Loans, net	960,282	941,132
Accrued interest receivable	3,247	3,398
Financial liabilities
Deposits	1,028,861	988,236
Other borrowings	22,000	10,000
Subordinated debt	4,981	4,977
Accrued interest payable	376	400
Level 1 [Member]
Financial assets
Cash and due from banks	140,610	114,342
Financial liabilities
Deposits	884,043	870,495
Level 2 [Member]
Financial assets
Securities available for sale	34,344	28,555
Accrued interest receivable	109	168
Financial liabilities
Deposits	145,310	121,136
Accrued interest payable	300	326
Level 3 [Member]
Financial assets
Loans, net	951,928	940,944
Accrued interest receivable	3,138	3,230
Financial liabilities
Other borrowings	22,539	10,032
Subordinated debt	5,103	5,112
Accrued interest payable	$ 76	$ 74