LOANS - Summary of activity in the allowance for loan losses by portfolio segment (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Past Due [Line Items]
Beginning balance	$ 2,153,174	$ 2,241,174
Provision (credit) for loan losses		(59,000)
Ending balance	2,153,174	2,182,174
Commercial Real Estate Portfolio Segment | Residential First Mortgage
Financing Receivable, Past Due [Line Items]
Beginning balance	1,092,474	1,254,174
Provision (credit) for loan losses	(17,400)	(68,500)
Ending balance	1,075,074	1,185,674
Commercial Real Estate Portfolio Segment | Commercial and Multi-Family Real Estate
Financing Receivable, Past Due [Line Items]
Beginning balance	768,600	841,000
Provision (credit) for loan losses	11,400	8,000
Ending balance	780,000	849,000
Commercial Real Estate Portfolio Segment | Construction
Financing Receivable, Past Due [Line Items]
Beginning balance	195,000	45,000
Provision (credit) for loan losses	13,000	3,000
Ending balance	208,000	48,000
Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Beginning balance	9,400	14,000
Provision (credit) for loan losses	(100)	(1,000)
Ending balance	9,300	13,000
Consumer | Home Equity and Other
Financing Receivable, Past Due [Line Items]
Beginning balance	87,700	87,000
Provision (credit) for loan losses	(6,900)	(500)
Ending balance	$ 80,800	$ 86,500