Guarantor Financial Statement Information - Consolidating Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Service related, net	$ 137	$ 317	$ 221	$ 781
Net gain on mortgage loans held for sale	262	127	428	251
Total revenues	399	444	649	1,032
Expenses:
Salaries, wages and benefits	238	177	453	357
General and administrative	254	162	482	346
Total expenses	492	339	935	703
Other income (expenses):
Interest income	162	140	296	285
Interest expense	(187)	(164)	(376)	(335)
Other income (expenses)	1	(2)	16	6
Gain (loss) from subsidiaries	0	0	0	0
Total other income (expenses), net	(24)	(26)	(64)	(44)
(Loss) income before income tax (benefit) expense	(117)	79	(350)	285
Less: Income tax benefit	29	(21)	76	(67)
Net (loss) income	(88)	58	(274)	218
Less: Net (loss) income attributable to non-controlling interests	(1)	0	(1)	0
Net (loss) income attributable to Successor/Predecessor	(87)	58	(273)	218
Eliminations
Revenues:
Service related, net	0	0	0	0
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	0	0	0	0
Expenses:
Salaries, wages and benefits	0	0	0	0
General and administrative	0	0	0	0
Total expenses	0	0	0	0
Other income (expenses):
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other income (expenses)	0	0	0	0
Gain (loss) from subsidiaries	46	(76)	185	(268)
Total other income (expenses), net	46	(76)	185	(268)
(Loss) income before income tax (benefit) expense	46	(76)	185	(268)
Less: Income tax benefit	0	0	0	0
Net (loss) income	46	(76)	185	(268)
Less: Net (loss) income attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to Successor/Predecessor	46	(76)	185	(268)
Mr. Cooper | Reportable entities
Revenues:
Service related, net	0	0	0	0
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	0	0	0	0
Expenses:
Salaries, wages and benefits	0	0	0	0
General and administrative	0	0	0	0
Total expenses	0	0	0	0
Other income (expenses):
Interest income	0	0	0	0
Interest expense	(39)	0	(77)	0
Other income (expenses)	0	0	0	0
Gain (loss) from subsidiaries	(48)	58	(196)	218
Total other income (expenses), net	(87)	58	(273)	218
(Loss) income before income tax (benefit) expense	(87)	58	(273)	218
Less: Income tax benefit	0	0	0	0
Net (loss) income	(87)	58	(273)	218
Less: Net (loss) income attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to Successor/Predecessor	(87)	58	(273)	218
Issuer | Reportable entities
Revenues:
Service related, net	21	247	2	637
Net gain on mortgage loans held for sale	262	127	428	251
Total revenues	283	374	430	888
Expenses:
Salaries, wages and benefits	198	149	372	301
General and administrative	179	134	344	290
Total expenses	377	283	716	591
Other income (expenses):
Interest income	147	127	265	258
Interest expense	(134)	(153)	(268)	(315)
Other income (expenses)	1	(3)	5	(4)
Gain (loss) from subsidiaries	2	18	11	50
Total other income (expenses), net	16	(11)	13	(11)
(Loss) income before income tax (benefit) expense	(78)	80	(273)	286
Less: Income tax benefit	29	(22)	76	(68)
Net (loss) income	(49)	58	(197)	218
Less: Net (loss) income attributable to non-controlling interests	(1)	0	(1)	0
Net (loss) income attributable to Successor/Predecessor	(48)	58	(196)	218
Guarantor (Subsidiaries of Issuer) | Reportable entities
Revenues:
Service related, net	5	7	11	13
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	5	7	11	13
Expenses:
Salaries, wages and benefits	1	1	2	2
General and administrative	1	0	2	1
Total expenses	2	1	4	3
Other income (expenses):
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other income (expenses)	0	0	0	0
Gain (loss) from subsidiaries	0	0	0	0
Total other income (expenses), net	0	0	0	0
(Loss) income before income tax (benefit) expense	3	6	7	10
Less: Income tax benefit	0	0	0	0
Net (loss) income	3	6	7	10
Less: Net (loss) income attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to Successor/Predecessor	3	6	7	10
Non-Guarantor (Subsidiaries of Issuer) | Reportable entities
Revenues:
Service related, net	111	63	208	131
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	111	63	208	131
Expenses:
Salaries, wages and benefits	39	27	79	54
General and administrative	74	28	136	55
Total expenses	113	55	215	109
Other income (expenses):
Interest income	15	13	31	27
Interest expense	(14)	(11)	(31)	(20)
Other income (expenses)	0	1	11	10
Gain (loss) from subsidiaries	0	0	0	0
Total other income (expenses), net	1	3	11	17
(Loss) income before income tax (benefit) expense	(1)	11	4	39
Less: Income tax benefit	0	1	0	1
Net (loss) income	(1)	12	4	40
Less: Net (loss) income attributable to non-controlling interests	0	0	0	0
Net (loss) income attributable to Successor/Predecessor	$ (1)	$ 12	$ 4	$ 40