Acquisitions and Dispositions - Property Acquisitions (Details)	3 Months Ended
Mar. 31, 2020 USD ($) property_Unit property	Mar. 31, 2019 USD ($) property
Business Acquisition [Line Items]
No. of Units \| property_Unit	1,880
Property Acquisition \| VIE \| Multi-family \| Corporate Joint Venture \| Wilmington, North Carolina
Business Acquisition [Line Items]
No. of Units \| property	264
Purchase Price	$ 38,000,000
Initial BRT Equity	$ 13,700,000
Ownership Percentage	80.00%
Capitalized Acquisition Costs	$ 459,000
Property Acquisition \| VIE \| Multi-family \| Corporate Joint Venture \| Kannapolis, North Carolina
Business Acquisition [Line Items]
No. of Units \| property		312
Purchase Price		$ 48,065,000
Initial BRT Equity		$ 11,231,000
Ownership Percentage		65.00%
Capitalized Acquisition Costs		$ 559,000
Property Acquisition \| VIE \| Multi-family \| Corporate Joint Venture \| Mortgages payable \| Wilmington, North Carolina
Business Acquisition [Line Items]
Acquisition Mortgage Debt	$ 23,160,000
Property Acquisition \| VIE \| Multi-family \| Corporate Joint Venture \| Mortgages payable \| Kannapolis, North Carolina
Business Acquisition [Line Items]
Acquisition Mortgage Debt		$ 33,347,000

Represents the contract purchase of the real estate investment property.

No definition available.

Name:	brt_RealEstateInvestmentPropertyContractPurchasePrice
Namespace Prefix:	brt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents acquisition-related costs incurred in connection with real estate investments acquired other than through foreclosure which costs have been expensed during the period.

+ References

No definition available.

+ Details

Name:	brt_RealEstateOtherAcquisitionsCostsExpensed
Namespace Prefix:	brt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118582676&loc=SL6759159-111685

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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