Investment in Unconsolidated Ventures - Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
ASSETS
Carry value of investment property	$ 166,760	$ 169,689
Cash and cash equivalents	16,874	22,699	$ 8,305
Other assets	7,738	7,282
Total Assets	385,602	390,610
Liabilities:
Mortgages payable	131,840	133,215
Accounts payable and accrued liabilities	21,538	20,772
Total Liabilities	190,451	191,050
Commitments and contingencies
Equity:
Total unconsolidated joint venture equity	195,274	199,653
Total Liabilities and Equity	385,602	390,610
Deferred mortgage costs	1,020	1,160
Mortgages payable
Equity:
Deferred mortgage costs	693	823
Unconsolidated joint ventures
ASSETS
Carry value of investment property	1,091,791	1,070,941
Cash and cash equivalents	14,700	12,804
Deposits and escrows	23,077	23,912
Other assets	5,687	4,136
Total Assets	1,135,255	1,111,793
Liabilities:
Mortgages payable	826,074	803,289
Accounts payable and accrued liabilities	20,081	19,731
Total Liabilities	846,155	823,020
Equity:
Total unconsolidated joint venture equity	289,100	288,773
Total Liabilities and Equity	1,135,255	1,111,793
BRT interest in joint venture equity	180,768	177,071
Real estate properties, net of accumulated depreciation	124,715	104,001
Unconsolidated joint ventures | Mortgages payable
Equity:
Deferred mortgage costs	$ 5,594	$ 5,839