INCOME TAXES - Summary of Provision for Federal Income Taxes Differs from that Computed by Applying the Federal Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Tax based on statutory rate	$ 3,641	$ 4,401	$ 3,619
Increase (decrease) resulting from:
Effect of tax-exempt income	(299)	(250)	(249)
Acquisition costs	0	32	29
Historical tax credits	29	6	6
Effect of tax rate change	0	0	338
State taxes	33	15	0
Other	46	(85)	(113)
Total income tax expense	$ 3,450	$ 4,119	$ 3,630
Effective rate	19.90%	19.70%	21.10%