ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of accumulated other comprehensive income (loss) (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 147,576,211	$ 128,468,076
Comprehensive (loss) income	(957,502)	3,049,239
Ending balance	145,025,932	143,078,150
Unrealized Gain and Losses on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(289,814)	100,569
Other comprehensive loss	(2,399,988)
Other comprehensive gain before reclassification		11,551
Comprehensive (loss) income	(2,399,988)	11,551
Ending balance	(2,689,802)	112,120
Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	17,158	(373,582)
Other comprehensive loss	41,589
Other comprehensive gain before reclassification		31,381
Comprehensive (loss) income	41,589	31,381
Ending balance	58,747	(342,201)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(272,656)	(273,013)
Other comprehensive loss	(2,358,399)
Other comprehensive gain before reclassification		42,932
Comprehensive (loss) income	(2,358,399)	42,932
Ending balance	$ (2,631,055)	$ (230,081)