Real Estate Properties - Schedule of Real Estate Properties Owned (Details) - USD ($) $ in Thousands	6 Months Ended
Mar. 31, 2018	Mar. 31, 2018	Sep. 30, 2017
Real Estate Properties
Land		$ 157,105	$ 138,094
Building		874,679	808,366
Building improvements		29,109	31,411
Real estate properties		1,060,893	977,871
Accumulated depreciation		(67,643)	(66,621)
Total real estate properties, net	$ 911,250	993,250	911,250
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real estate properties, beginning balance	911,250
Additions	198,296
Capitalized Costs and Improvements	5,247
Depreciation	(17,888)
Sales	(103,655)
Real estate properties, ending balance	993,250
Multi-family
Real Estate Properties
Total real estate properties, net	890,300	959,474	890,300
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real estate properties, beginning balance	890,300
Additions	185,415
Capitalized Costs and Improvements	5,247
Depreciation	(17,833)
Sales	(103,655)
Real estate properties, ending balance	959,474
Multi-family \| West Nashville, TN
Real Estate Properties
Total real estate properties, net	10,448	23,329	10,448
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real estate properties, beginning balance	10,448
Additions	12,881
Capitalized Costs and Improvements	0
Depreciation	0
Sales	0
Real estate properties, ending balance	23,329
Land
Real Estate Properties
Total real estate properties, net	8,021	8,021	8,021
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real estate properties, beginning balance	8,021
Additions	0
Capitalized Costs and Improvements	0
Depreciation	0
Sales	0
Real estate properties, ending balance	8,021
Shopping centers/Retail \| VIE \| RBHTRB Newark Holdings LLC
Real Estate Properties
Total real estate properties, net	2,481	$ 2,426	$ 2,481
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Real estate properties, beginning balance	2,481
Additions	0
Capitalized Costs and Improvements	0
Depreciation	(55)
Sales	0
Real estate properties, ending balance	$ 2,426

Investment Building

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- Definition

Investment Building Improvements

+ References

No definition available.

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- Definition

Represents the depreciation and amortization in real estate investment property.

+ References

No definition available.

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Represents the aggregate of the amount of improvements and costs capitalized to real estate investments during the period.

+ References

No definition available.

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Amount of increase in real estate investments from acquisitions other than through foreclosure for entities with a substantial portion of business acquiring and holding investment real estate. Excludes improvements and costs capitalized to real estate investments during the period.

+ References

No definition available.

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- Definition

Reflects for the period the total of the carrying amount of the commercial, industrial and residential land and buildings sold plus certain overhead and other costs incurred to place the real estate in saleable condition, capitalized interest costs in the properties sold, and inventory impairment losses recognized. This element would most likely be used by an entity whose principal activities involve real estate or which has significant real estate operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
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- Definition

Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6812-107765

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.13)
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- Definition

The cumulative amount of depreciation for real estate property held for investment purposes.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(3))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(d))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Amount of real estate investments, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; (7) other real estate investments; (8) real estate joint ventures; and (9) unconsolidated real estate and other joint ventures not separately presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(d))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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