Investment in Unconsolidated Ventures - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Total revenues	$ 6,961	$ 6,816	$ 14,060	$ 13,740
Expenses:
Real estate operating expenses	3,166	3,004	6,283	6,062
Interest expense	1,609	1,809	3,269	3,669
Depreciation	1,416	1,809	2,953	3,370
Total expenses	9,865	9,579	19,293	19,425
Total revenues less total expenses	(2,904)	(2,763)	(5,233)	(5,685)
Impairment charges	(520)	0	(520)	0
Net loss from joint ventures	33	31	67	63
BRT's equity in loss from joint ventures	6,027	(4,246)	2,262	(9,077)
Unconsolidated Joint Ventures
Revenues:
Rental and other revenue	33,005	31,542	65,677	62,385
Total revenues	33,005	31,542	65,677	62,385
Expenses:
Real estate operating expenses	15,233	14,674	30,936	29,206
Interest expense	8,472	8,766	16,994	17,523
Depreciation	9,791	10,417	20,176	20,773
Total expenses	33,496	33,857	68,106	67,502
Total revenues less total expenses	(491)	(2,315)	(2,429)	(5,117)
Equity in earnings	5	9	14	17
Impairment charges	(490)	0	(2,813)	0
Insurance recoveries	490	0	2,813	0
Gain on insurance recoveries	0	338	0	338
Net loss from joint ventures	(486)	(1,968)	(2,415)	(4,762)
BRT's equity in loss from joint ventures	$ (492)	$ (1,387)	$ (1,837)	$ (3,202)