Securities Available-for-Sale - Summary of gross unrealized losses and fair value for those investments with unrealized losses (Detail) $ in Thousands	Jun. 30, 2020 USD ($) Number	Dec. 31, 2019 USD ($) Number
Less than 12 Months, Number of Securities | Number	14	14
Less than 12 Months, Fair Value	$ 4,793	$ 10,766
Less than 12 Months, Unrealized Losses	(37)	$ (91)
More than 12 Months, Number of Securities | Number		1
More than 12 Months, Fair Value		$ 1,991
More than 12 Months, Unrealized Losses		(9)
Total, Fair Value	4,793	12,757
Total, Unrealized Losses	$ (37)	$ (100)
U.S. Government-sponsored enterprises obligations [Member]
Less than 12 Months, Number of Securities | Number		2
Less than 12 Months, Fair Value		$ 1,995
Less than 12 Months, Unrealized Losses		$ (5)
More than 12 Months, Number of Securities | Number		1
More than 12 Months, Fair Value		$ 1,991
More than 12 Months, Unrealized Losses		(9)
Total, Fair Value		3,986
Total, Unrealized Losses		$ (14)
U.S. Government agency small business administration pools guaranteed by SBA [Member]
Less than 12 Months, Number of Securities | Number		2
Less than 12 Months, Fair Value		$ 2,740
Less than 12 Months, Unrealized Losses		(20)
Total, Fair Value		2,740
Total, Unrealized Losses		$ (20)
Collateralized mortgage obligations issued by the FHLMC [Member]
Less than 12 Months, Number of Securities | Number		1
Less than 12 Months, Fair Value		$ 980
Less than 12 Months, Unrealized Losses		(6)
Total, Fair Value		980
Total, Unrealized Losses		$ (6)
Residential mortgage backed securities [Member]
Less than 12 Months, Number of Securities | Number		1
Less than 12 Months, Fair Value		$ 999
Less than 12 Months, Unrealized Losses		(2)
Total, Fair Value		999
Total, Unrealized Losses		$ (2)
Municipal bonds [Member]
Less than 12 Months, Number of Securities | Number	14	8
Less than 12 Months, Fair Value	$ 4,793	$ 4,052
Less than 12 Months, Unrealized Losses	(37)	(58)
Total, Fair Value	4,793	4,052
Total, Unrealized Losses	$ (37)	$ (58)