Indebtedness - Notes Payable Summary (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt Outstanding	$ 578,000,000	$ 595,000,000
Servicing Segment | Notes Payable, Other
Debt Instrument [Line Items]
Debt outstanding, gross	578,000,000	595,000,000
Debt Outstanding	578,000,000	595,000,000
Collateral Pledged	765,000,000	777,000,000
Servicing Segment | Notes Payable, Other | Nationstar agency advance receivables trust
Debt Instrument [Line Items]
Capacity Amount	350,000,000
Debt outstanding, gross	225,000,000	218,000,000
Collateral Pledged	$ 262,000,000	255,000,000
Servicing Segment | Notes Payable, Other | Nationstar agency advance receivables trust | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.50%
Servicing Segment | Notes Payable, Other | Nationstar agency advance receivables trust | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.60%
Servicing Segment | Notes Payable, Other | Nationstar mortgage advance receivable trust
Debt Instrument [Line Items]
Capacity Amount	$ 325,000,000
Debt outstanding, gross	195,000,000	209,000,000
Collateral Pledged	$ 265,000,000	284,000,000
Servicing Segment | Notes Payable, Other | Nationstar mortgage advance receivable trust | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.50%
Servicing Segment | Notes Payable, Other | Nationstar mortgage advance receivable trust | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	6.50%
Servicing Segment | Notes Payable, Other | MBS servicer advance facility (2014)
Debt Instrument [Line Items]
Capacity Amount	$ 135,000,000
Debt outstanding, gross	89,000,000	90,000,000
Collateral Pledged	$ 160,000,000	149,000,000
Servicing Segment | Notes Payable, Other | MBS servicer advance facility (2014) | CPRATE
Debt Instrument [Line Items]
Basis spread on rate	2.50%
Servicing Segment | Notes Payable, Other | Nationstar agency advance financing facility
Debt Instrument [Line Items]
Capacity Amount	$ 125,000,000
Debt outstanding, gross	69,000,000	78,000,000
Collateral Pledged	$ 78,000,000	89,000,000
Servicing Segment | Notes Payable, Other | Nationstar agency advance financing facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.50%
Servicing Segment | Notes Payable, Other | Nationstar agency advance financing facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	7.40%
Servicing Segment | Advance facilities
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ 0	0
Originations Segment | Mortgage loans, net
Debt Instrument [Line Items]
Debt Outstanding	2,027,000,000	1,528,000,000
Collateral Pledged	2,177,000,000	1,628,000,000
Originations Segment | Reverse mortgage interests
Debt Instrument [Line Items]
Debt Outstanding	764,000,000	722,000,000
Collateral Pledged	899,000,000	838,000,000
Originations Segment | MSR
Debt Instrument [Line Items]
Debt Outstanding	260,000,000	100,000,000
Collateral Pledged	1,340,000,000	1,686,000,000
Originations Segment | Notes Payable to Banks
Debt Instrument [Line Items]
Debt outstanding, gross	2,791,000,000	2,250,000,000
Collateral Pledged	3,076,000,000	2,466,000,000
Originations Segment | Notes Payable to Banks | $1,000 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	1,000,000,000
Debt outstanding, gross	210,000,000	137,000,000
Collateral Pledged	$ 215,000,000	140,000,000
Originations Segment | Notes Payable to Banks | $1,000 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.60%
Originations Segment | Notes Payable to Banks | $1,000 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.50%
Originations Segment | Notes Payable to Banks | $950 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 950,000,000
Debt outstanding, gross	462,000,000	560,000,000
Collateral Pledged	$ 525,000,000	622,000,000
Originations Segment | Notes Payable to Banks | $950 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.70%
Originations Segment | Notes Payable to Banks | $950 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	3.50%
Originations Segment | Notes Payable to Banks | $800 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 800,000,000
Debt outstanding, gross	388,000,000	464,000,000
Collateral Pledged	$ 491,000,000	514,000,000
Originations Segment | Notes Payable to Banks | $800 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.90%
Originations Segment | Notes Payable to Banks | $800 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.90%
Originations Segment | Notes Payable to Banks | $600 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 600,000,000
Debt outstanding, gross	168,000,000	151,000,000
Collateral Pledged	$ 188,000,000	168,000,000
Originations Segment | Notes Payable to Banks | $600 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	2.30%
Originations Segment | Notes Payable to Banks | $500 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 500,000,000
Debt outstanding, gross	427,000,000	290,000,000
Collateral Pledged	$ 441,000,000	299,000,000
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	2.00%
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.30%
Originations Segment | Notes Payable to Banks | $500 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 500,000,000
Debt outstanding, gross	223,000,000	220,000,000
Collateral Pledged	$ 250,000,000	248,000,000
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.50%
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.80%
Originations Segment | Notes Payable to Banks | $500 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 500,000,000
Debt outstanding, gross	218,000,000	187,000,000
Collateral Pledged	$ 235,000,000	200,000,000
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.50%
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	3.00%
Originations Segment | Notes Payable to Banks | $500 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 500,000,000
Debt outstanding, gross	115,000,000	119,000,000
Collateral Pledged	$ 118,000,000	122,000,000
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.80%
Originations Segment | Notes Payable to Banks | $500 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.80%
Originations Segment | Notes Payable to Banks | $250 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 250,000,000
Debt outstanding, gross	245,000,000	0
Collateral Pledged	$ 246,000,000	0
Originations Segment | Notes Payable to Banks | $250 warehouse facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on rate	1.90%
Originations Segment | Notes Payable to Banks | $250 warehouse facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on rate	2.50%
Originations Segment | Notes Payable to Banks | $200 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 200,000,000
Debt outstanding, gross	186,000,000	0
Collateral Pledged	$ 187,000,000	0
Originations Segment | Notes Payable to Banks | $200 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	1.50%
Originations Segment | Notes Payable to Banks | $200 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 200,000,000
Debt outstanding, gross	75,000,000	103,000,000
Collateral Pledged	$ 100,000,000	132,000,000
Originations Segment | Notes Payable to Banks | $200 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	2.30%
Originations Segment | Notes Payable to Banks | $200 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 200,000,000
Debt outstanding, gross	0	18,000,000
Collateral Pledged	$ 0	19,000,000
Basis spread on rate	2.30%
Originations Segment | Notes Payable to Banks | $165 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 165,000,000
Debt outstanding, gross	67,000,000	0
Collateral Pledged	$ 68,000,000	0
Basis spread on rate	1.60%
Originations Segment | Notes Payable to Banks | $50 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 50,000,000
Debt outstanding, gross	6,000,000	0
Collateral Pledged	$ 9,000,000	0
Basis spread on rate	1.50%
Originations Segment | Notes Payable to Banks | $40 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 40,000,000
Debt outstanding, gross	1,000,000	1,000,000
Collateral Pledged	$ 3,000,000	2,000,000
Originations Segment | Notes Payable to Banks | $40 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	3.00%
Originations Segment | Mortgage servicing rights
Debt Instrument [Line Items]
Debt outstanding, gross	$ 260,000,000	100,000,000
Collateral Pledged	1,340,000,000	1,686,000,000
Originations Segment | Mortgage servicing rights | $200 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	200,000,000
Debt outstanding, gross	50,000,000	0
Collateral Pledged	$ 232,000,000	430,000,000
Originations Segment | Mortgage servicing rights | $200 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	3.80%
Originations Segment | Mortgage servicing rights | $200 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 200,000,000
Debt outstanding, gross	100,000,000	100,000,000
Collateral Pledged	$ 884,000,000	928,000,000
Originations Segment | Mortgage servicing rights | $200 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	4.00%
Originations Segment | Mortgage servicing rights | $175 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 175,000,000
Debt outstanding, gross	70,000,000	0
Collateral Pledged	$ 129,000,000	226,000,000
Originations Segment | Mortgage servicing rights | $175 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	2.30%
Originations Segment | Mortgage servicing rights | $50 warehouse facility
Debt Instrument [Line Items]
Capacity Amount	$ 50,000,000
Debt outstanding, gross	40,000,000	0
Collateral Pledged	$ 95,000,000	102,000,000
Originations Segment | Mortgage servicing rights | $50 warehouse facility | LIBOR
Debt Instrument [Line Items]
Basis spread on rate	2.80%
Originations Segment | Warehouse Facilities
Debt Instrument [Line Items]
Debt outstanding, gross	$ 3,051,000,000	2,350,000,000
Debt Outstanding	3,050,000,000	2,349,000,000
Collateral Pledged	4,416,000,000	0
Unamortized debt issuance costs	$ (1,000,000)	$ (1,000,000)