INVESTMENTS IN REAL ESTATE AND OTHER SECURITIES - Summary of Real Estate Securities in an Unrealized Loss Position - Associated Intent to Sell (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Securities New Residential intends to sell
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 0	$ 0
Amortized Cost Basis After Credit Impairment	0	0
Gross Unrealized Losses, Credit	0	0
Gross Unrealized Losses, Non-Credit		0
Securities New Residential is more likely than not to be required to sell
Debt Securities, Available-for-sale [Line Items]
Fair Value	0	0
Amortized Cost Basis After Credit Impairment	0	0
Gross Unrealized Losses, Credit	0	0
Credit impaired securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	122,086	228,228
Amortized Cost Basis After Credit Impairment	134,639	237,626
Gross Unrealized Losses, Credit	(10,369)	(3,232)
Gross Unrealized Losses, Non-Credit	(12,553)	(9,398)
Non-credit impaired securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	3,051,699	4,726,409
Amortized Cost Basis After Credit Impairment	3,111,229	4,767,837
Gross Unrealized Losses, Credit	0	0
Gross Unrealized Losses, Non-Credit	(59,530)	(41,428)
Total debt securities in an unrealized loss position
Debt Securities, Available-for-sale [Line Items]
Fair Value	3,173,785	4,954,637
Amortized Cost Basis After Credit Impairment	3,245,868	5,005,463
Gross Unrealized Losses, Credit	(10,369)	(3,232)
Gross Unrealized Losses, Non-Credit	$ (72,083)	$ (50,826)