ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of accumulated other comprehensive income (loss) (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 145,025,932	$ 143,078,150	$ 147,576,211	$ 128,468,076
Comprehensive (loss) income	(2,458,737)	1,479,317	(3,416,239)	4,528,556
Ending balance	140,460,794	144,622,102	140,460,794	144,622,102
Unrealized Gain and Losses on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,689,802)	112,120	(289,814)	100,569
Amounts reclassified	(4,142,333)	9,212	(6,542,321)	20,763
Comprehensive (loss) income	(4,142,333)	9,212	(6,542,321)	20,763
Ending balance	(6,832,135)	121,332	(6,832,135)	121,332
Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	58,747	(342,201)	17,158	(373,582)
Amounts reclassified	41,589	31,381	83,178	62,762
Comprehensive (loss) income	41,589	31,381	83,178	62,762
Ending balance	100,336	(310,820)	100,336	(310,820)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,631,055)	(230,081)	(272,656)	(273,013)
Amounts reclassified	(4,100,744)	40,593	(6,459,143)	83,525
Comprehensive (loss) income	(4,100,744)	40,593	(6,459,143)	83,525
Ending balance	$ (6,731,799)	$ (189,488)	$ (6,731,799)	$ (189,488)