SEGMENT REPORTING (Details) $ in Thousands		3 Months Ended								12 Months Ended
		Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment										2
Revenues:
Rental and other revenues from real estate properties										$ 118,872	$ 104,477	$ 95,202
Other income										763	1,294	3,319
Total revenues		$ 31,481	$ 30,154	$ 29,651	$ 28,349	$ 28,387	$ 26,861	$ 24,883	$ 25,640	119,635	105,771	98,521
Expenses:
Real estate operating expenses										57,665	51,279	47,519
Interest expense										34,389	28,171	23,878
General and administrative										9,210	9,396	8,536
Depreciation										38,504	30,491	23,180
Advisor's fees, related party										0	0	693
Property acquisition costs										0	0	3,852
Total expenses		37,045	35,897	34,548	32,278	32,504	30,333	28,473	28,027	139,768	119,337	107,658
Total revenues less total expenses		(5,564)	(5,743)	(4,897)	(3,929)	(4,117)	(3,472)	(3,590)	(2,387)	(20,133)	(13,566)	(9,137)
Equity in loss of unconsolidated joint ventures		(173)	(127)	(63)	(25)	(77)	(307)	0	0	(388)	(384)	0
Gain on sale of real estate		424	0	51,981	12,519	16,763	0	0	35,838	64,924	52,601	46,477
Loss on extinguishment of debt		0	0	(593)	(257)	(664)	0	0	(799)	(850)	(1,463)	(4,547)
Income from continuing operations		(4,042)	(5,870)	49,655	8,308	11,905	(3,779)	(3,590)	32,652	48,051	37,188	33,179
Provision for taxes		96	101	(253)	106	61	41	1,108	350	50	1,560	700
Income from continuing operations, net of taxes						11,844	(3,820)	(4,698)	32,302	48,001	35,628	32,479
Net income (loss)		(4,138)	(5,971)	49,908	8,202					48,001	35,628	45,158
Income from continuing operations, net of taxes		1,027	1,282	(24,686)	(1,851)	(6,383)	418	469	(16,532)	(24,228)	(22,028)	(13,869)
Net income (loss) attributable to common stockholders		(3,111)	$ (4,689)	$ 25,222	$ 6,351	5,461	$ (3,402)	$ (4,229)	$ 15,770	23,773	13,600	31,289
Total Assets	[1]	$ 1,153,364				993,897				1,153,364	993,897
Discontinued operations, net of non-controlling interests										0	0	14,339
Income (loss) from continuing operations										23,773	13,600	16,950
Gain on sale of partnership interest										$ 0	0	386
Operating Segments
Revenues:
Rental and other revenues from real estate properties											104,477	95,202
Other income											1,294	3,319
Total revenues											105,771	98,521
Expenses:
Real estate operating expenses											51,279	47,519
Interest expense											28,171	23,878
General and administrative											9,396	8,536
Depreciation											30,491	23,180
Advisor's fees, related party												693
Property acquisition costs												3,852
Provision for federal taxes												700
Total expenses											119,337	107,658
Total revenues less total expenses											(13,566)	(9,137)
Equity in loss of unconsolidated joint ventures											(384)
Gain on sale of real estate											52,601	46,477
Loss on extinguishment of debt											(1,463)	(4,547)
Income from continuing operations											37,188	33,179
Provision for taxes											1,560
Income from continuing operations, net of taxes												32,479
Net income (loss)											35,628
Income from continuing operations, net of taxes											(22,028)	(15,528)
Net income (loss) attributable to common stockholders											13,600	31,289
Total Assets						993,897					993,897	874,899
Discontinued operations, net of non-controlling interests												14,338
Income (loss) from continuing operations												16,951
Gain on sale of partnership interest												386
Multi-Family Real Estate | Operating Segments
Revenues:
Rental and other revenues from real estate properties											102,938	93,795
Other income											(9)	0
Total revenues											102,929	93,795
Expenses:
Real estate operating expenses											50,733	46,936
Interest expense											26,782	23,739
General and administrative											9,208	8,313
Depreciation											30,381	22,251
Advisor's fees, related party												593
Property acquisition costs												3,852
Provision for federal taxes												686
Total expenses											117,104	105,684
Total revenues less total expenses											(14,175)	(11,889)
Equity in loss of unconsolidated joint ventures											(417)
Gain on sale of real estate											52,152	45,206
Loss on extinguishment of debt											(1,463)	(4,547)
Income from continuing operations											36,097	29,156
Provision for taxes											1,529
Income from continuing operations, net of taxes												28,470
Net income (loss)											34,568
Income from continuing operations, net of taxes											(21,896)	(15,420)
Net income (loss) attributable to common stockholders											12,672
Total Assets						976,806					976,806	843,898
Income (loss) from continuing operations												13,050
Gain on sale of partnership interest												386
Other Real Estate | Operating Segments
Revenues:
Rental and other revenues from real estate properties											1,539	1,407
Other income											1,303	3,319
Total revenues											2,842	4,726
Expenses:
Real estate operating expenses											546	583
Interest expense											1,389	139
General and administrative											188	223
Depreciation											110	929
Advisor's fees, related party												100
Property acquisition costs												0
Provision for federal taxes												14
Total expenses											2,233	1,974
Total revenues less total expenses											609	2,752
Equity in loss of unconsolidated joint ventures											33
Gain on sale of real estate											449	1,271
Loss on extinguishment of debt											0	0
Income from continuing operations											1,091	4,023
Provision for taxes											31
Income from continuing operations, net of taxes												4,009
Net income (loss)											1,060
Income from continuing operations, net of taxes											(132)	(108)
Net income (loss) attributable to common stockholders											928
Total Assets						$ 17,091					$ 17,091	31,001
Income (loss) from continuing operations												3,901
Gain on sale of partnership interest												$ 0

[1] The Company's consolidated balance sheets include the assets and liabilities of consolidated variable interest entities (VIEs). See note 4. The consolidated balance sheets include the following amounts related to the Company's VIEs as of September 30, 2018 and 2017, respectively: $586,623 and $707,546 of real estate properties, $6,699 and $8,626 of cash and cash equivalents, $11,837 and $13,873 of deposits and escrows, $6,781 and $8,148 of other assets, $38,852 and $8,969 of real estate properties held for sale, $481,569 and $558,568 of mortgages payable, $12,841 and $14,419 of accounts payable and accrued liabilities.