INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Income) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 28, 2009	Oct. 03, 2005	Mar. 02, 2005	Sep. 30, 2004	Aug. 31, 2004	Nov. 30, 2001
Revenues
Rental income									$ 61,661,551	$ 60,012,174	$ 57,535,734
Laundry and sundry income									441,159	465,140	478,330
Total Revenues	$ 14,825,754	$ 15,142,266	$ 15,759,106	$ 16,375,584	$ 15,447,866	$ 15,155,901	$ 14,991,403	$ 14,882,144	62,102,710	60,477,314	58,014,064
Expenses
Administrative									2,209,780	2,495,272	2,204,923
Depreciation and amortization									18,410,811	14,684,248	15,568,973
Management fee									2,452,814	2,409,151	2,326,225
Operating									5,766,160	5,682,264	5,542,605
Renting									864,542	953,043	779,503
Repairs and maintenance									8,781,789	9,191,561	9,187,714
Taxes and insurance									8,647,781	7,790,008	7,485,749
Total Expenses									47,133,677	43,205,547	43,095,692
Income Before Other Income (Expense)	2,952,494	3,227,636	4,444,469	4,344,434	4,563,916	4,177,017	4,579,147	3,951,687	14,969,033	17,271,767	14,918,372
Other Income (Expense)
Interest expense									(13,705,415)	(12,201,966)	(12,389,680)
Interest income									195	607	344
Total Other Income (Expense)	(3,922,516)	(3,666,920)	(2,979,418)	(2,975,651)	(2,665,403)	(2,793,038)	(2,814,903)	(2,451,171)	(13,544,505)	(10,724,515)	(10,749,282)
Net (Loss) Income	$ (970,022)	$ (439,284)	$ 1,465,051	$ 1,368,783	$ 1,898,513	$ 1,383,979	$ 1,764,244	$ 1,500,516	$ 1,424,528	$ 6,547,252	$ 4,169,090
NERA 50%
Other Income (Expense)
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%
NERA 40%
Other Income (Expense)
Ownership interest (as a percent)	40.00%				40.00%				40.00%	40.00%	40.00%
Investment Properties
Revenues
Rental income									$ 21,776,809	$ 24,648,947	$ 23,919,253
Laundry and sundry income									129,713	165,096	163,958
Total Revenues									21,906,522	24,814,043	24,083,211
Expenses
Administrative									327,697	377,298	360,792
Depreciation and amortization									5,956,370	5,903,401	5,832,195
Management fee									580,029	664,341	652,200
Operating									1,633,551	1,791,071	1,942,878
Renting									466,296	495,103	645,890
Repairs and maintenance									2,441,880	2,511,741	2,666,148
Taxes and insurance									3,383,874	3,074,653	2,827,058
Total Expenses									14,789,697	14,817,608	14,927,161
Income Before Other Income (Expense)									7,116,825	9,996,435	9,156,050
Other Income (Expense)
Interest expense									(6,742,727)	(6,915,193)	(6,866,175)
Other (loss)											(3,829,950)
Gain on sale of real estate										734,635	4,410,541
Total Other Income (Expense)										(6,180,558)	(6,285,584)
Net (Loss) Income									374,098	3,815,877	2,870,466
Proportionate share of net income (loss)									160,715	1,678,554	1,640,054
Investment Properties | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									55,380	761,014	2,459,336
Investment Properties | NERA 40%
Other Income (Expense)
Proportionate share of net income (loss)									105,335	917,540	(819,282)
Hamilton Essex 81
Revenues
Rental income									874,212	1,743,610	1,654,459
Laundry and sundry income									12,495	14,350	14,595
Total Revenues									886,707	1,757,960	1,669,054
Expenses
Administrative									20,296	29,307	21,146
Depreciation and amortization									488,315	483,748	475,646
Management fee									42,958	69,039	59,246
Operating									79,195	89,002	78,979
Renting									22,782	43,534	41,946
Repairs and maintenance									128,728	152,930	159,486
Taxes and insurance									256,162	245,086	247,729
Total Expenses									1,038,436	1,112,646	1,084,178
Income Before Other Income (Expense)									(151,729)	645,314	584,876
Other Income (Expense)
Interest expense									(299,161)	(466,737)	(440,676)
Total Other Income (Expense)										(466,737)	(440,676)
Net (Loss) Income									$ (450,890)	$ 178,577	$ 144,200
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%
Hamilton Essex 81 | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									$ (225,445)	$ 89,289	$ 72,100
Hamilton Essex Development
Revenues
Rental income									19,848	222,183	244,137
Total Revenues									19,848	222,183	244,137
Expenses
Administrative									4,026	25,369	9,280
Depreciation and amortization									20,297	20,297	8,706
Management fee									2,203	8,683	8,632
Operating										8
Renting											37,353
Repairs and maintenance									3,180	3,180	8,643
Taxes and insurance									61,612	61,493	64,529
Total Expenses									91,318	119,030	137,143
Income Before Other Income (Expense)									(71,470)	103,153	106,994
Other Income (Expense)
Net (Loss) Income									$ (71,470)	$ 103,153	$ 106,994
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%
Hamilton Essex Development | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									$ (35,735)	$ 51,577	$ 53,497
345 Franklin
Revenues
Rental income									1,516,648	1,613,295	1,567,718
Laundry and sundry income									604	2,844	5,410
Total Revenues									1,517,252	1,616,139	1,573,128
Expenses
Administrative									36,431	24,610	27,601
Depreciation and amortization									339,513	345,282	347,547
Management fee									57,986	62,486	65,058
Operating									67,885	80,581	76,512
Renting									52,571	36,918	44,869
Repairs and maintenance									138,991	125,474	130,926
Taxes and insurance									167,456	154,731	147,217
Total Expenses									860,833	830,082	839,730
Income Before Other Income (Expense)									656,419	786,057	733,398
Other Income (Expense)
Interest expense									(369,742)	(377,448)	(384,824)
Total Other Income (Expense)										(377,448)	(384,824)
Net (Loss) Income									$ 286,677	$ 408,609	$ 348,574
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%						50.00%
345 Franklin | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									$ 143,339	$ 204,305	$ 174,287
Hamilton 1025
Revenues
Rental income									96,223	93,116	112,785
Total Revenues									96,223	93,116	112,785
Expenses
Administrative									12,995	7,497	5,939
Depreciation and amortization									3,264	7,655
Management fee									3,529	3,556	4,503
Operating									276	974	1,606
Renting										64	108
Repairs and maintenance										28,399	94,680
Taxes and insurance									17,416	22,213	46,164
Total Expenses									37,480	70,358	153,000
Income Before Other Income (Expense)									58,743	22,758	(40,215)
Other Income (Expense)
Gain on sale of real estate										306,075	1,972,876
Total Other Income (Expense)										306,075	1,972,876
Net (Loss) Income									$ 58,743	$ 328,834	$ 1,932,662
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%			50.00%
Hamilton 1025 | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									$ 29,372	$ 164,417	$ 966,331
Hamilton Bay Apts
Revenues
Rental income										3,541	74,812
Total Revenues										3,541	74,812
Expenses
Administrative										6,147	12,566
Depreciation and amortization											30,000
Management fee										145	3,091
Operating											1,435
Repairs and maintenance										10,266	92,268
Taxes and insurance										5,206	36,094
Total Expenses										21,764	175,454
Income Before Other Income (Expense)										(18,223)	(100,642)
Other Income (Expense)
Gain on sale of real estate										428,560	2,437,665
Total Other Income (Expense)										428,560	2,437,665
Net (Loss) Income										410,337	$ 2,337,023
Ownership interest (as a percent)											50.00%		50.00%
Hamilton Bay Apts | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)										205,169	$ 1,168,512
Hamilton Minuteman
Revenues
Rental income									1,165,027	1,136,912	1,077,105
Laundry and sundry income									2,951	6,033	(364)
Total Revenues									1,167,978	1,142,945	1,076,741
Expenses
Administrative									13,603	7,722	5,449
Depreciation and amortization									348,994	357,932	355,463
Management fee									46,275	45,624	42,852
Operating									102,397	83,872	93,795
Renting									7,994	5,324	5,940
Repairs and maintenance									95,185	133,812	121,222
Taxes and insurance									144,664	131,821	127,505
Total Expenses									759,112	766,107	752,226
Income Before Other Income (Expense)									408,866	376,838	324,515
Other Income (Expense)
Interest expense									(238,233)	(235,883)	(237,707)
Total Other Income (Expense)										(235,883)	(237,707)
Net (Loss) Income									$ 170,633	$ 140,955	$ 86,807
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%				50.00%
Hamilton Minuteman | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									$ 85,317	$ 70,478	$ 43,404
Hamilton on Main Apts
Revenues
Rental income									3,497,639	3,429,864	3,419,218
Laundry and sundry income									35,302	41,174	38,080
Total Revenues									3,532,941	3,471,038	3,457,298
Expenses
Administrative									59,014	68,877	56,339
Depreciation and amortization									1,059,165	1,046,022	1,032,394
Management fee									132,513	132,195	131,500
Operating									362,318	398,286	388,387
Renting									73,837	47,817	25,947
Repairs and maintenance									513,642	651,948	663,314
Taxes and insurance									449,692	404,805	426,665
Total Expenses									2,650,181	2,749,950	2,724,546
Income Before Other Income (Expense)									882,760	721,088	732,752
Other Income (Expense)
Interest expense									(765,692)	(769,526)	(770,342)
Total Other Income (Expense)										(769,526)	(770,342)
Net (Loss) Income									$ 117,068	$ (48,438)	$ (37,590)
Ownership interest (as a percent)	50.00%				50.00%				50.00%	50.00%	50.00%					50.00%
Hamilton on Main Apts | NERA 50%
Other Income (Expense)
Proportionate share of net income (loss)									$ 58,534	$ (24,219)	$ (18,795)
Dexter Park
Revenues
Rental income									14,607,212	16,406,426	15,769,019
Laundry and sundry income									78,361	100,695	106,237
Total Revenues									14,685,573	16,507,121	15,875,256
Expenses
Administrative									181,332	207,769	222,472
Depreciation and amortization									3,696,822	3,642,465	3,582,439
Management fee									294,565	342,613	337,318
Operating									1,021,480	1,138,348	1,302,164
Renting									309,112	361,446	489,727
Repairs and maintenance									1,562,154	1,405,732	1,395,609
Taxes and insurance									2,286,872	2,049,298	1,731,155
Total Expenses									9,352,337	9,147,671	9,060,884
Income Before Other Income (Expense)									5,333,236	7,359,450	6,814,372
Other Income (Expense)
Interest expense									(5,069,899)	(5,065,599)	(5,032,626)
Other (loss)											(3,829,950)
Total Other Income (Expense)										(5,065,599)	(8,862,576)
Net (Loss) Income									$ 263,337	$ 2,293,851	$ (2,048,202)
Ownership interest (as a percent)	40.00%				40.00%				40.00%	40.00%	40.00%	40.00%
Dexter Park | NERA 40%
Other Income (Expense)
Proportionate share of net income (loss)									$ 105,335	$ 917,540	$ (819,282)