INVESTMENT IN UNCONSOLIDATED JOINT VENTURES (Details 3) (USD $)	3 Months Ended								12 Months Ended																			12 Months Ended							12 Months Ended							12 Months Ended													12 Months Ended							12 Months Ended							12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Hamilton Essex 81	Dec. 31, 2011 Hamilton Essex 81	Dec. 31, 2010 Hamilton Essex 81	Dec. 31, 2012 Hamilton Essex 81 NERA 50%	Dec. 31, 2011 Hamilton Essex 81 NERA 50%	Dec. 31, 2010 Hamilton Essex 81 NERA 50%	Dec. 31, 2012 Hamilton Essex Development	Dec. 31, 2011 Hamilton Essex Development	Dec. 31, 2010 Hamilton Essex Development	Dec. 31, 2012 Hamilton Essex Development NERA 50%	Dec. 31, 2011 Hamilton Essex Development NERA 50%	Dec. 31, 2010 Hamilton Essex Development NERA 50%	Dec. 31, 2012 345 Franklin	Dec. 31, 2011 345 Franklin	Dec. 31, 2010 345 Franklin	Nov. 30, 2001 345 Franklin	Dec. 31, 2012 345 Franklin NERA 50%	Dec. 31, 2011 345 Franklin NERA 50%	Dec. 31, 2010 345 Franklin NERA 50%	Dec. 31, 2012 Hamilton 1025	Dec. 31, 2011 Hamilton 1025	Dec. 31, 2010 Hamilton 1025	Mar. 02, 2005 Hamilton 1025	Dec. 31, 2012 Hamilton 1025 NERA 50%	Dec. 31, 2011 Hamilton 1025 NERA 50%	Dec. 31, 2010 Hamilton 1025 NERA 50%	Dec. 31, 2012 Hamilton Bay Sales	Dec. 31, 2011 Hamilton Bay Sales	Dec. 31, 2010 Hamilton Bay Sales	Oct. 03, 2005 Hamilton Bay Sales	Dec. 31, 2012 Hamilton Bay Sales NERA 50%	Dec. 31, 2011 Hamilton Bay Sales NERA 50%	Dec. 31, 2010 Hamilton Bay Sales NERA 50%	Dec. 31, 2012 Hamilton Bay	Dec. 31, 2011 Hamilton Bay	Dec. 31, 2010 Hamilton Bay	Dec. 31, 2012 Hamilton Bay NERA 50%	Dec. 31, 2011 Hamilton Bay NERA 50%	Dec. 31, 2010 Hamilton Bay NERA 50%	Dec. 31, 2012 Hamilton Minuteman	Dec. 31, 2011 Hamilton Minuteman	Dec. 31, 2010 Hamilton Minuteman	Sep. 30, 2004 Hamilton Minuteman	Dec. 31, 2012 Hamilton Minuteman NERA 50%	Dec. 31, 2011 Hamilton Minuteman NERA 50%	Dec. 31, 2010 Hamilton Minuteman NERA 50%	Dec. 31, 2012 Hamilton on Main	Dec. 31, 2011 Hamilton on Main	Dec. 31, 2010 Hamilton on Main	Aug. 31, 2004 Hamilton on Main	Dec. 31, 2012 Hamilton on Main NERA 50%	Dec. 31, 2011 Hamilton on Main NERA 50%	Dec. 31, 2010 Hamilton on Main NERA 50%	Dec. 31, 2012 Dexter Park	Dec. 31, 2011 Dexter Park	Dec. 31, 2010 Dexter Park	Oct. 28, 2009 Dexter Park	Dec. 31, 2012 Dexter Park NERA 40%	Dec. 31, 2011 Dexter Park NERA 40%	Dec. 31, 2010 Dexter Park NERA 40%	Dec. 31, 2012 Total	Dec. 31, 2011 Total	Dec. 31, 2010 Total	Dec. 31, 2012 Total NERA 50%	Dec. 31, 2011 Total NERA 50%	Dec. 31, 2010 Total NERA 50%	Dec. 31, 2012 Total NERA 40%	Dec. 31, 2011 Total NERA 40%	Dec. 31, 2010 Total NERA 40%
Revenues
Rental income									$ 35,244,008	$ 33,608,799	$ 31,816,175	$ 1,270,141	$ 1,244,322	$ 1,122,915				$ 287,537	$ 255,050	$ 275,950				$ 1,178,712	$ 1,136,831	$ 1,097,957					$ 861,998	$ 816,015	$ 794,993					$ 235,061	$ 232,938	$ 221,191					$ 886,122	$ 863,657	$ 839,361				$ 809,707	$ 789,897	$ 765,509					$ 2,623,994	$ 2,491,957	$ 2,455,222					$ 12,202,615	$ 11,559,414	$ 11,019,862					$ 20,355,887	$ 19,390,080	$ 18,592,960
Laundry and sundry income									388,401	426,803	439,782	15,363	16,589	16,184										1,206	2,367	2,436																									2,435	1,362	762					20,952	20,599	19,780					98,042	97,275	97,902					137,999	138,193	137,063
Total Revenues	9,104,015	8,875,596	8,800,416	8,852,382	8,760,538	8,648,526	8,345,643	8,280,894	35,632,409	34,035,602	32,255,957	1,285,504	1,260,911	1,139,099				287,537	255,050	275,950				1,179,918	1,139,198	1,100,393					861,998	816,015	794,993					235,061	232,938	221,191					886,122	863,657	839,361				812,142	791,258	766,271					2,644,946	2,512,556	2,475,002					12,300,657	11,656,690	11,117,764					20,493,885	19,528,273	18,730,023
Expenses
Administrative									1,825,951	1,707,408	1,772,599	15,237	20,839	13,709				1,749	1,339					27,942	24,424	30,904					5,142	11,258	13,038					7,553	5,396	7,073					34,600	18,625	17,324				7,825	10,249	10,288					46,400	36,155	39,289					219,218	163,511	148,097					365,666	291,796	279,724
Depreciation and amortization									6,092,725	5,910,746	5,531,509	409,488	424,695	425,450				11,638	8,498	6,254				441,704	443,055	439,666					256,696	257,961	269,475					82,287	103,536	98,678					297,737	329,930	359,727				317,231	322,216	320,553					957,452	965,324	981,881					5,733,920	5,698,657	9,428,284					8,508,153	8,553,872	12,329,966
Management fees												55,308	49,677	46,734				11,502	11,040	11,040				48,596	45,829	45,559					34,517	32,120	31,795					9,894	9,486	9,245					34,659	33,916	33,345				32,615	31,666	31,563					104,807	100,581	97,239					261,355	251,071	244,178					593,253	565,386	550,698
Operating									3,633,619	4,080,647	3,784,401	112,172	121,521	134,016										62,277	66,278	62,994					816	1,733	1,777					1,251	239						1,190	732	411				73,092	54,650	63,841					341,054	371,687	358,827					1,006,570	929,543	960,328					1,598,421	1,546,382	1,582,193
Renting									183,529	365,110	528,686	18,350	8,058	24,785										5,326	19,206	49,517					6,815	13,322	8,576					1,894	1,750	375					4,053	8,927	6,213				3,538	3,559	3,770					10,974	15,140	15,361					74,705	144,149	281,545					125,655	214,111	390,142
Repairs and maintenance									5,179,408	5,056,054	4,886,724	118,786	127,528	134,941				5,475	3,050					82,052	71,479	80,190					320,997	300,534	376,560					70,812	78,167	76,510					273,652	316,782	344,852				57,448	98,904	99,553					380,605	371,109	342,310					880,103	935,839	859,088					2,189,930	2,303,393	2,314,005
Taxes and insurance									4,348,492	4,146,554	4,082,588	197,566	184,119	179,939				49,237	47,709	46,658				106,785	97,028	98,151					145,755	143,002	127,637					46,017	45,303	42,465					161,137	155,681	132,188				102,505	92,300	96,213					337,256	325,868	318,150					1,485,297	1,300,995	1,451,017					2,631,555	2,392,005	2,492,417
Total Expenses	5,704,596	5,730,319	5,413,735	5,861,694	5,722,971	5,665,232	5,508,842	5,773,941	22,710,344	22,670,986	21,916,664	926,908	936,438	959,574				79,600	71,636	63,952				774,681	767,299	806,981					770,738	759,930	828,857					219,707	243,877	234,346					807,027	864,593	894,061				594,254	613,544	625,780					2,178,549	2,185,864	2,153,057					9,661,169	9,423,765	13,372,537					16,012,632	15,866,945	19,939,145
Income Before Other Income (loss) and Discontinued Operations	3,399,419	3,145,277	3,386,681	2,990,688	3,037,567	2,983,294	2,836,801	2,506,953	12,922,065	11,364,616	10,339,293	358,596	324,473	179,525				207,937	183,414	211,998				405,237	371,899	293,412					91,260	56,085	(33,864)					15,354	(10,939)	(13,155)					79,095	(936)	(54,700)				217,888	177,714	140,491					466,397	326,693	321,944					2,639,488	2,232,924	(2,254,773)					4,481,253	3,661,328	(1,209,122)
Other Income (Loss)
Interest expense									(7,802,999)	(7,965,422)	(8,053,628)	(497,631)	(503,102)	(507,425)				(60,451)	(61,593)	(62,694)				(486,051)	(494,468)	(504,667)					(288,470)	(289,222)	(289,042)					(98,361)	(98,010)	(97,909)					(271,283)	(271,348)	(271,389)				(317,448)	(317,927)	(317,360)					(840,874)	(848,786)	(860,500)					(5,092,838)	(5,113,523)	(5,116,598)					(7,953,407)	(7,997,979)	(8,027,583)
Interest income									2,216	3,861	5,932			3						2				48	49	47					74	88	90					215	457	569							2						1,780							8						3,219	5					337	3,814	2,505
Interest Income from Note																																						6,180	8,904	11,445																																6,180	8,904	11,445
Gain on the sale of real estate										7,720,459
Other Income (Expenses)													(2,331)												(5,375)							(3,621)								11,021						(2,271)	9,478					(61,589)							(1,152)	2,168						(3,500)	(17,720)						(79,839)	4,947
Total Other Income (Expense)	(2,214,288)	(2,370,824)	(2,339,420)	(2,363,735)	(2,469,002)	(2,523,314)	(2,480,305)	(2,402,740)	(9,288,267)	(9,875,361)	(11,918,392)	(497,631)	(505,433)	(507,422)				(60,451)	(61,593)	(62,692)				(486,003)	(499,793)	(504,619)					(288,395)	(292,756)	(288,952)					(91,966)	(88,649)	(74,874)					(271,283)	(273,619)	(261,909)				(317,448)	(379,515)	(315,581)					(840,874)	(849,938)	(858,323)					(5,092,838)	(5,113,804)	(5,134,313)					(7,946,890)	(8,065,100)	(8,008,686)
Net Income (loss)	1,185,131	774,453	1,047,261	626,953	568,257	456,926	8,093,285	172,812	3,633,798	9,291,281	(1,359,232)	(139,035)	(180,960)	(327,897)				147,486	121,821	149,305				(80,766)	(127,894)	(211,208)					(197,135)	(236,671)	(322,816)					(76,612)	(99,588)	(88,029)					(192,188)	(274,555)	(316,608)				(99,560)	(201,801)	(175,090)					(374,477)	(523,245)	(536,379)					(2,453,350)	(2,880,880)	(7,389,086)					(3,465,636)	(4,403,772)	(9,217,808)
Proportionate share of net loss															$ (69,517)	$ (90,480)	$ (163,948)				$ 73,743	$ 60,911	$ 74,653					$ (40,383)	$ (63,947)	$ (105,604)					$ (98,567)	$ (118,335)	$ (161,408)					$ (38,306)	$ (49,794)	$ (44,015)				$ (96,094)	$ (137,277)	$ (158,304)					$ (49,780)	$ (100,900)	$ (87,545)					$ (187,239)	$ (261,622)	$ (268,189)					$ (981,340)	$ (1,152,352)	$ (2,955,635)	$ (1,487,483)	$ (1,913,798)	$ (3,869,995)	$ (506,143)	$ (761,446)	$ (914,361)	$ (981,340)	$ (1,152,352)	$ (2,955,635)
Percentage of ownership interest															50.00%	50.00%	50.00%				50.00%	50.00%	50.00%				50.00%	50.00%	50.00%	50.00%				50.00%	50.00%	50.00%	50.00%				50.00%	50.00%	50.00%	50.00%				50.00%	50.00%	50.00%				50.00%	50.00%	50.00%	50.00%				50.00%	50.00%	50.00%	50.00%				40.00%	40.00%	40.00%	40.00%				50.00%	50.00%	50.00%	40.00%	40.00%	40.00%