Fair Value Measurement - Schedule of Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Inputs Asset Quantitative Information [Line Items]
Other real estate owned and repossessed assets	$ 4,178	$ 7,265
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Inputs Asset Quantitative Information [Line Items]
Impaired loans	2,362
Other real estate owned and repossessed assets	4,178	7,265
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Inputs Asset Quantitative Information [Line Items]
Impaired loans	2,362
Other real estate owned and repossessed assets	$ 4,178	$ 7,265
Impaired loans, Appraisal adjustments	(29.80%)
Impaired Loans Liquidation Expenses	(5.30%)
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Fair Value Inputs Asset Quantitative Information [Line Items]
Impaired loans, Appraisal adjustments	(29.80%)
Impaired Loans Liquidation Expenses	(5.30%)