Indebtedness - Notes Payable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Outstanding debt	$ 595,000,000
Warehouse facilities
Debt Instrument [Line Items]
Debt issuance costs	(1,000,000)
Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding debt	2,349,000,000
Servicing | Advance facilities
Debt Instrument [Line Items]
Debt issuance costs	0
Servicing | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross	595,000,000
Collateral Pledged	777,000,000
Outstanding debt	595,000,000
Servicing | Nationstar agency advance receivables trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Capacity Amount	350,000,000
Outstanding, gross	218,000,000
Collateral Pledged	255,000,000
Servicing | Nationstar mortgage advance receivable trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Capacity Amount	325,000,000
Outstanding, gross	209,000,000
Collateral Pledged	284,000,000
Servicing | MBS servicer advance facility (2014) | Notes Payable, Other Payables
Debt Instrument [Line Items]
Capacity Amount	125,000,000
Outstanding, gross	90,000,000
Collateral Pledged	149,000,000
Servicing | Nationstar agency advance financing facility | Notes Payable, Other Payables
Debt Instrument [Line Items]
Capacity Amount	125,000,000
Outstanding, gross	78,000,000
Collateral Pledged	89,000,000
Servicing | MBS advance financing facility | Notes Payable, Other Payables
Debt Instrument [Line Items]
Capacity Amount	0
Outstanding, gross	0
Collateral Pledged	0
Originations | Warehouse facilities
Debt Instrument [Line Items]
Outstanding, gross	2,250,000,000
Collateral Pledged	2,466,000,000
Originations | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross	2,350,000,000
Collateral Pledged	4,152,000,000
Originations | Mortgage Servicing Rights
Debt Instrument [Line Items]
Outstanding, gross	100,000,000
Collateral Pledged	1,686,000,000
Originations | $1,200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	1,200,000,000
Outstanding, gross	464,000,000
Collateral Pledged	514,000,000
Originations | $1,000 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	1,000,000,000
Outstanding, gross	137,000,000
Collateral Pledged	140,000,000
Originations | $950 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	950,000,000
Outstanding, gross	560,000,000
Collateral Pledged	622,000,000
Originations | $600 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	600,000,000
Outstanding, gross	151,000,000
Collateral Pledged	168,000,000
Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	500,000,000
Outstanding, gross	290,000,000
Collateral Pledged	299,000,000
Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	500,000,000
Outstanding, gross	220,000,000
Collateral Pledged	248,000,000
Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	500,000,000
Outstanding, gross	187,000,000
Collateral Pledged	200,000,000
Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	500,000,000
Outstanding, gross	119,000,000
Collateral Pledged	122,000,000
Originations | $300 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	300,000,000
Outstanding, gross	103,000,000
Collateral Pledged	132,000,000
Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	200,000,000
Outstanding, gross	18,000,000
Collateral Pledged	19,000,000
Originations | $40 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	40,000,000
Outstanding, gross	1,000,000
Collateral Pledged	2,000,000
Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	200,000,000
Outstanding, gross	0
Collateral Pledged	430,000,000
Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	200,000,000
Outstanding, gross	100,000,000
Collateral Pledged	928,000,000
Originations | $175 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	175,000,000
Outstanding, gross	0
Collateral Pledged	226,000,000
Originations | $50 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Capacity Amount	50,000,000
Outstanding, gross	0
Collateral Pledged	102,000,000
Mortgage loans, net | Originations
Debt Instrument [Line Items]
Collateral Pledged	1,628,000,000
Outstanding debt	1,528,000,000
Reverse mortgage interests, net | Originations
Debt Instrument [Line Items]
Collateral Pledged	838,000,000
Outstanding debt	722,000,000
MSR and other collateral | Originations
Debt Instrument [Line Items]
Collateral Pledged	1,686,000,000
Outstanding debt	$ 100,000,000
LIBOR | Servicing | Nationstar agency advance financing facility | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.50%
LIBOR | Servicing | MBS advance financing facility | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	3.50%
LIBOR | Originations | $600 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.50%
LIBOR | Originations | $300 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.30%
LIBOR | Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.30%
LIBOR | Originations | $40 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	3.00%
LIBOR | Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	3.80%
LIBOR | Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	4.00%
LIBOR | Originations | $175 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.30%
LIBOR | Originations | $50 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	4.50%
CPRATE | Servicing | MBS servicer advance facility (2014) | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.50%
Minimum | LIBOR | Servicing | Nationstar agency advance receivables trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.50%
Minimum | LIBOR | Servicing | Nationstar mortgage advance receivable trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.50%
Minimum | LIBOR | Originations | $1,200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.90%
Minimum | LIBOR | Originations | $1,000 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.60%
Minimum | LIBOR | Originations | $950 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.70%
Minimum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.00%
Minimum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.50%
Minimum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.50%
Minimum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	1.80%
Maximum | LIBOR | Servicing | Nationstar agency advance receivables trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.60%
Maximum | LIBOR | Servicing | Nationstar mortgage advance receivable trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Basis spread on variable rate percentage	6.50%
Maximum | LIBOR | Originations | $1,200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	3.80%
Maximum | LIBOR | Originations | $1,000 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.50%
Maximum | LIBOR | Originations | $950 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	3.50%
Maximum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.30%
Maximum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.80%
Maximum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	3.00%
Maximum | LIBOR | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Basis spread on variable rate percentage	2.80%
Predecessor
Debt Instrument [Line Items]
Outstanding debt		$ 855,000,000
Predecessor | Warehouse facilities
Debt Instrument [Line Items]
Debt issuance costs		(1,000,000)
Predecessor | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding debt		3,285,000,000
Predecessor | Servicing | Advance facilities
Debt Instrument [Line Items]
Debt issuance costs		0
Predecessor | Servicing | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross		855,000,000
Collateral Pledged		1,100,000,000
Outstanding debt		855,000,000
Predecessor | Servicing | Nationstar agency advance receivables trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross		416,000,000
Collateral Pledged		492,000,000
Predecessor | Servicing | Nationstar mortgage advance receivable trust | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross		230,000,000
Collateral Pledged		287,000,000
Predecessor | Servicing | MBS servicer advance facility (2014) | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross		44,000,000
Collateral Pledged		140,000,000
Predecessor | Servicing | Nationstar agency advance financing facility | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross		102,000,000
Collateral Pledged		117,000,000
Predecessor | Servicing | MBS advance financing facility | Notes Payable, Other Payables
Debt Instrument [Line Items]
Outstanding, gross		63,000,000
Collateral Pledged		64,000,000
Predecessor | Originations | Warehouse facilities
Debt Instrument [Line Items]
Outstanding, gross		3,226,000,000
Collateral Pledged		3,476,000,000
Predecessor | Originations | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		3,286,000,000
Collateral Pledged		4,737,000,000
Predecessor | Originations | Mortgage Servicing Rights
Debt Instrument [Line Items]
Outstanding, gross		60,000,000
Collateral Pledged		1,261,000,000
Predecessor | Originations | $1,200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		889,000,000
Collateral Pledged		960,000,000
Predecessor | Originations | $1,000 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		299,000,000
Collateral Pledged		308,000,000
Predecessor | Originations | $950 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		721,000,000
Collateral Pledged		785,000,000
Predecessor | Originations | $600 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		333,000,000
Collateral Pledged		347,000,000
Predecessor | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		0
Collateral Pledged		0
Predecessor | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		305,000,000
Collateral Pledged		337,000,000
Predecessor | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		246,000,000
Collateral Pledged		272,000,000
Predecessor | Originations | $500 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		233,000,000
Collateral Pledged		239,000,000
Predecessor | Originations | $300 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		116,000,000
Collateral Pledged		141,000,000
Predecessor | Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		80,000,000
Collateral Pledged		81,000,000
Predecessor | Originations | $40 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		4,000,000
Collateral Pledged		6,000,000
Predecessor | Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		0
Collateral Pledged		377,000,000
Predecessor | Originations | $200 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		50,000,000
Collateral Pledged		594,000,000
Predecessor | Originations | $175 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		0
Collateral Pledged		200,000,000
Predecessor | Originations | $50 warehouse facility | Notes Payable to Banks
Debt Instrument [Line Items]
Outstanding, gross		10,000,000
Collateral Pledged		90,000,000
Predecessor | Mortgage loans, net | Originations
Debt Instrument [Line Items]
Collateral Pledged		1,901,000,000
Outstanding debt		1,792,000,000
Predecessor | Reverse mortgage interests, net | Originations
Debt Instrument [Line Items]
Collateral Pledged		1,575,000,000
Outstanding debt		1,434,000,000
Predecessor | MSR and other collateral | Originations
Debt Instrument [Line Items]
Collateral Pledged		1,261,000,000
Outstanding debt		$ 60,000,000