FAIR VALUE MEASUREMENT - Financial Assets Measured at Fair Value on a Recurring Basis using Level 3 Inputs (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Non-Agency
Gains (losses) included in net income
Included in gain (loss) on settlement of investments, net	$ 18,400
Excess MSRs Investees
Purchases, sales and repayments
New Residential’s ownership	50.00%	50.00%
Recurring Basis | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	$ 11,503,879
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	(8,736)
Included in change in fair value of investments in excess mortgage servicing rights	(32,650)
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	6,056
Included in servicing revenue, net	(81,986)
Included in change in fair value of investments in mortgage servicing rights financing receivable	75,828
Included in change in fair value of servicer advance investments	70,469
Included in gain (loss) on settlement of investments, net	29,746
Included in other income	2,288
Gains (losses) included in other comprehensive income, net of tax	259,313
Interest income	768,794
Purchases, sales and repayments
Purchases	13,338,888
Proceeds from sales	(166,400)
Proceeds from repayments	(12,043,659)
Ocwen Transaction	(488,752)
Balance, ending	13,233,078
Recurring Basis | Level 3 | Servicer Advances
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	5,706,593
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivable	0
Included in change in fair value of servicer advance investments	70,469
Included in gain (loss) on settlement of investments, net	9,327
Included in other income	0
Gains (losses) included in other comprehensive income, net of tax	0
Interest income	446,666
Purchases, sales and repayments
Purchases	9,328,137
Proceeds from sales	0
Proceeds from repayments	(11,035,170)
Ocwen Transaction	(481,220)
Balance, ending	4,044,802
Recurring Basis | Level 3 | Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	659,483
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	(81,986)
Included in change in fair value of investments in mortgage servicing rights financing receivable	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income	0
Gains (losses) included in other comprehensive income, net of tax	0
Interest income	0
Purchases, sales and repayments
Purchases	1,125,252
Proceeds from sales	0
Proceeds from repayments	0
Ocwen Transaction	0
Balance, ending	1,702,749
Recurring Basis | Level 3 | Mortgage Servicing Rights Financing Receivable
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	0
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivable	75,828
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income	0
Gains (losses) included in other comprehensive income, net of tax	0
Interest income	0
Purchases, sales and repayments
Purchases	467,118
Proceeds from sales	0
Proceeds from repayments	0
Ocwen Transaction	64,450
Balance, ending	607,396
Recurring Basis | Level 3 | Non-Agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	3,543,560
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	(8,736)
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivable	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	18,426
Included in other income	340
Gains (losses) included in other comprehensive income, net of tax	259,313
Interest income	246,890
Purchases, sales and repayments
Purchases	2,418,381
Proceeds from sales	(166,400)
Proceeds from repayments	(787,584)
Ocwen Transaction	0
Balance, ending	5,524,190
Recurring Basis | Level 3 | MSRs Agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	381,757
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	(9,550)
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	0
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivable	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income	1,755
Gains (losses) included in other comprehensive income, net of tax	0
Interest income	20,505
Purchases, sales and repayments
Purchases	0
Proceeds from sales	0
Proceeds from repayments	(60,618)
Ocwen Transaction	0
Balance, ending	333,849
Recurring Basis | Level 3 | MSRs Agency | Excess MSRs Investees
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	194,788
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	0
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees	6,056
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivable	0
Included in change in fair value of servicer advance investments	0
Included in gain (loss) on settlement of investments, net	0
Included in other income	0
Gains (losses) included in other comprehensive income, net of tax	0
Interest income	0
Purchases, sales and repayments
Purchases	0
Proceeds from sales	0
Proceeds from repayments	(25,211)
Ocwen Transaction	0
Balance, ending	175,633
Recurring Basis | Level 3 | MSRs Non-Agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning	1,017,698
Transfers from Level 3	0
Transfers to Level 3	0
Gains (losses) included in net income
Included in other-than-temporary impairment (''OTTI'') on securities	0
Included in change in fair value of investments in excess mortgage servicing rights	(23,100)
Included in change in fair value of investments in excess mortgage servicing rights, equity method investees
Included in servicing revenue, net	0
Included in change in fair value of investments in mortgage servicing rights financing receivable	0
Included in change in fair value of servicer advance investments
Included in gain (loss) on settlement of investments, net	1,993
Included in other income	193
Gains (losses) included in other comprehensive income, net of tax	0
Interest income	54,733
Purchases, sales and repayments
Purchases	0
Proceeds from sales	0
Proceeds from repayments	(135,076)
Ocwen Transaction	(71,982)
Balance, ending	$ 844,459