Parent Company only Financial Information - Condensed Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Interest expense	$ (1,576)	$ (1,698)	$ (1,593)	$ (1,696)	$ (1,985)	$ (2,000)	$ (1,996)	$ (2,121)	$ (6,563)	$ (8,102)
Non-interest expense	994	1,302	956	921	917	1,028	777	1,290	4,173	4,012
Income (loss) before provision for income taxes	4,448	4,330	5,807	3,877	2,562	821	2,192	665	18,462	6,240
Provision for income taxes	1,267	1,114	1,645	1,068	777	326	642	192	5,094	1,937
Net income	$ 3,181	$ 3,216	$ 4,162	$ 2,809	$ 1,785	$ 495	$ 1,550	$ 473	13,368	4,303
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Interest expense									(1,477)	(495)
Non-interest expense									(543)	(1,025)
Income (loss) before provision for income taxes									(2,020)	(1,520)
Provision for income taxes									596	371
Income (loss) before equity in undistributed subsidiary income									(1,424)	(1,149)
Equity in undistributed subsidiary income									14,792	5,452
Net income									$ 13,368	$ 4,303