REAL ESTATE EQUITY SECURITIES (Narrative) (Details) $ in Thousands		12 Months Ended
	Oct. 29, 2019 USD ($) shares	Dec. 31, 2019 USD ($) investment shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Number of investments in equity securities | investment		3
Payments to acquire investments		$ 0	$ 0	$ 12,514
Interest and Dividend Income, Securities, Operating, Available-for-sale		$ 5,800	$ 6,000	$ 2,500
Plymouth Industrial REIT, Inc.
Schedule of Available-for-sale Securities [Line Items]
Stock repurchased during period (in shares) | shares		555,555
Payments to acquire investments		$ 10,000
Plymouth Industrial REIT, Inc. | Common Stock
Schedule of Available-for-sale Securities [Line Items]
Number of securities sold (in shares) | shares		139,714
Proceeds from sale of equity securities		$ 2,700
Whitestone REIT | Common Stock
Schedule of Available-for-sale Securities [Line Items]
Number of securities sold (in shares) | shares		1,781,894
Proceeds from sale of equity securities		$ 25,400
SREIT
Schedule of Available-for-sale Securities [Line Items]
Payments to acquire investments	$ 5,200
Number of shares owned (in shares) | shares	7,186,000