INVESTMENT IN EQUITY SECURITIES (Details) - USD ($) $ / shares in Units, shares in Millions		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 19, 2020	Oct. 27, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2016	Dec. 31, 2019
Marketable Securities [Line Items]
Investment in equity securities			$ 30,185,000		$ 30,185,000			$ 42,618,000
Unrealized gain (loss) on investment in equity securities			$ 138,000	$ (2,294,000)	$ (12,433,000)	$ 11,731,000
RESI
Marketable Securities [Line Items]
Number of investment shares acquired (in shares)							4.1
Number of securities outstanding (in shares)			3.5		3.5			3.5
Investment in equity securities			$ 30,200,000		$ 30,200,000			$ 42,600,000
Unrealized gain (loss) on investment in equity securities			100,000	(2,300,000)	(12,400,000)	11,700,000
Investment income, dividend			0	$ 500,000	500,000	$ 1,700,000
Number of investment shares disposed (in shares)				0.1		0.7
Proceeds from investment shares sold			$ 0	$ 1,300,000	$ 0	$ 7,800,000
RESI | Subsequent Event
Marketable Securities [Line Items]
Number of investment shares disposed (in shares)		1.6
Proceeds from investment shares sold		$ 21,100,000
Price of shares in merger agreement (in dollars per share)	$ 13.50
RESI, Shares Sold During Period
Marketable Securities [Line Items]
Unrealized gain (loss) on investment in equity securities				$ (100,000)		$ 1,900,000