Deposits - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Interest expense on retail certificates of deposit $100,000 or greater	$ 2,100,000	$ 467,000	$ 446,000
Certificates of deposit, at or above FDIC insurance limit of 250,000	60,800,000	31,800,000
Deposit accounts of directors, executive officers and their respective affiliates	$ 7,200,000	$ 6,800,000