Investment in Unconsolidated Ventures - Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
ASSETS
Real estate properties, net of accumulated depreciation of $64,831 and $66,945	$ 643,869		$ 651,603
Cash and cash equivalents	31,336		20,281	$ 57,045
Other assets	16,241		16,786
Total Assets	727,806		732,118
Liabilities:
Mortgages payable, net of deferred costs of $1,234 and $1,421	423,383		403,792
Accounts payable and accrued liabilities	21,544		22,631
Total Liabilities	482,060		482,048
Commitments and contingencies
Equity:
Total unconsolidated joint venture equity	245,746	$ 243,334	250,070	$ 249,150	$ 214,202	$ 202,951
Total Liabilities and Equity	727,806		732,118
Deferred costs	4,705		4,941
Unconsolidated Joint Ventures
ASSETS
Real estate properties, net of accumulated depreciation of $64,831 and $66,945	280,305		318,304
Cash and cash equivalents	6,743		6,591
Other assets	37,701		35,372
Total Assets	324,749		360,267
Liabilities:
Mortgages payable, net of deferred costs of $1,234 and $1,421	233,445		255,261
Accounts payable and accrued liabilities	6,880		8,222
Total Liabilities	240,325		263,483
Commitments and contingencies
Equity:
Total unconsolidated joint venture equity	84,424		96,784
Total Liabilities and Equity	324,749		360,267
BRT's interest in joint venture equity	35,530		42,576
Unconsolidated Joint Ventures
Equity:
Real estate properties, net of accumulated depreciation	64,831		66,945
Unconsolidated Joint Ventures | Mortgages payable
Equity:
Deferred costs	$ 1,234		$ 1,421