Fair Value Measurement and Fair Value of Financial Instruments - Fair Value of Assets Measured on Non-recurring Basis (Detail) - Fair Value, Measurements, Non-recurring - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets:
Impaired loans	$ 4,592	$ 5,789
Loans held for sale	2,793	1,743
Other real estate owned and other repossessed assets	354	563
(Level 1)
Assets:
Impaired loans	0	0
Loans held for sale	0	0
Other real estate owned and other repossessed assets	0	0
(Level 2)
Assets:
Impaired loans	0	0
Loans held for sale	2,793	1,743
Other real estate owned and other repossessed assets	0	0
(Level 3)
Assets:
Impaired loans	4,592	5,789
Loans held for sale	0	0
Other real estate owned and other repossessed assets	$ 354	$ 563