TRANSACTIONS WITH AFFILIATES AND AFFILIATED ENTITIES - Narrative (Details) $ / shares in Units, $ in Thousands		1 Months Ended		6 Months Ended
	May 19, 2020 USD ($)	Mar. 31, 2020 USD ($)	Feb. 28, 2019 shares	Jun. 30, 2020 USD ($) purchasers $ / shares shares	Dec. 31, 2019 USD ($) $ / shares
Related Party Transaction [Line Items]
Management agreement, renewal term (in years)				1 year
Termination fee, number of months' pay (in months)				12 months
Proportion of directors' votes needed to terminate				0.6667
Number of purchasers | purchasers				6
Mortgage-backed securities				$ 6,100,000
Proceeds from sale of mortgage-backed securities		$ 3,300,000
Options granted (in shares) | shares				1,619,739
Common stock, par value (in dollars per share) | $ / shares				$ 0.01	$ 0.01
Share-based Payment Arrangement, Nonemployee
Related Party Transaction [Line Items]
Options granted (in shares) | shares			4,600,000
Common stock purchase warrants | Share-based Payment Arrangement, Nonemployee
Related Party Transaction [Line Items]
Options granted (in shares) | shares				43,400,000
Percentage of lenders and recipients managed by an affiliate of the manager	0.48
2020 Term Loan
Related Party Transaction [Line Items]
Debt instrument, term	3 years
Principal outstanding	$ 600,000			$ 600,000	$ 0
Manager
Related Party Transaction [Line Items]
Management fee rate (percent)				1.50%
Incentive compensation percentage				25.00%
Interest rate for incentive compensation				10.00%
Fortress Purchaser
Related Party Transaction [Line Items]
Mortgage-backed securities				$ 1,850,000
Payments to acquire mortgage-backed securities		$ 1,000,000