Acquisitions and Dispositions - Property Acquisitions (Details)	9 Months Ended
	Sep. 30, 2020 USD ($) property property_Unit	Sep. 30, 2019 USD ($) property
Business Acquisition [Line Items]
No. of Units | property_Unit	1,880
Property Acquisition | VIE | Multi-family | Corporate Joint Venture
Business Acquisition [Line Items]
No. of Units | property		840
Purchase Price		$ 109,465,000
Initial BRT Equity		27,176,000
Capitalized Acquisition Costs		$ 1,245,000
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 | Birmingham, Alabama
Business Acquisition [Line Items]
No. of Units | property		328
Purchase Price		$ 43,000,000
Initial BRT Equity		$ 11,625,000
Ownership Percentage		80.00%
Capitalized Acquisition Costs		$ 546,000
Property Acquisition | VIE | Multi-family | Corporate Joint Venture | Auburn, AL
Business Acquisition [Line Items]
No. of Units | property		200
Purchase Price		$ 18,400,000
Initial BRT Equity		$ 4,320,000
Ownership Percentage		80.00%
Capitalized Acquisition Costs		$ 140,000
Property Acquisition | VIE | Multi-family | Corporate Joint Venture | Mortgages payable
Business Acquisition [Line Items]
Acquisition Mortgage Debt		80,097,000
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
Property Acquisition | VIE | Multi-family | Corporate Joint Venture | Mortgages payable | Birmingham, Alabama
Business Acquisition [Line Items]
Acquisition Mortgage Debt		32,250,000
Property Acquisition | VIE | Multi-family | Corporate Joint Venture | Mortgages payable | Auburn, AL
Business Acquisition [Line Items]
Acquisition Mortgage Debt		$ 14,500,000