Business Segment Reporting - Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenues:
Service related, net	$ 227	$ 258	$ 186	$ 479
Net gain on mortgage loans held for sale	645	360	1,594	788
Total revenues	872	618	1,780	1,267
Total expenses	431	478	1,294	1,413
Other income (expenses)
Interest income	56	163	250	459
Interest expense	(165)	(196)	(534)	(572)
Other income (expenses), net	(51)	0	(50)	16
Total other expenses, net	(160)	(33)	(334)	(97)
Income (loss) before income tax expense (benefit)	281	107	152	(243)
Depreciation and amortization for property and equipment and intangible assets	19	22	56	67
Total assets	21,755	18,478	21,755	18,478	$ 18,305
Operating Segments | Servicing
Revenues:
Service related, net	92	126	(202)	108
Net gain on mortgage loans held for sale	40	37	119	90
Total revenues	132	163	(83)	198
Total expenses	99	171	370	555
Other income (expenses)
Interest income	40	137	180	388
Interest expense	(105)	(120)	(335)	(343)
Other income (expenses), net	0	0	0	0
Total other expenses, net	(65)	17	(155)	45
Income (loss) before income tax expense (benefit)	(32)	9	(608)	(312)
Depreciation and amortization for property and equipment and intangible assets	6	5	14	13
Total assets	14,707	12,065	14,707	12,065
Operating Segments | Originations
Revenues:
Service related, net	27	22	68	57
Net gain on mortgage loans held for sale	605	312	1,475	687
Total revenues	632	334	1,543	744
Total expenses	195	155	528	404
Other income (expenses)
Interest income	16	24	69	64
Interest expense	(15)	(24)	(55)	(67)
Other income (expenses), net	0	(1)	0	4
Total other expenses, net	1	(1)	14	1
Income (loss) before income tax expense (benefit)	438	178	1,029	341
Depreciation and amortization for property and equipment and intangible assets	5	4	12	13
Total assets	4,250	4,386	4,250	4,386
Operating Segments | Xome
Revenues:
Service related, net	108	112	320	316
Net gain on mortgage loans held for sale	0	0	0	0
Total revenues	108	112	320	316
Total expenses	94	101	285	301
Other income (expenses)
Interest income	0	0	0	0
Interest expense	0	0	0	0
Other income (expenses), net	1	3	3	14
Total other expenses, net	1	3	3	14
Income (loss) before income tax expense (benefit)	15	14	38	29
Depreciation and amortization for property and equipment and intangible assets	5	4	11	11
Total assets	135	172	135	172
Corporate/Other
Revenues:
Service related, net	0	(2)	0	(2)
Net gain on mortgage loans held for sale	0	11	0	11
Total revenues	0	9	0	9
Total expenses	43	51	111	153
Other income (expenses)
Interest income	0	2	1	7
Interest expense	(45)	(52)	(144)	(162)
Other income (expenses), net	(52)	(2)	(53)	(2)
Total other expenses, net	(97)	(52)	(196)	(157)
Income (loss) before income tax expense (benefit)	(140)	(94)	(307)	(301)
Depreciation and amortization for property and equipment and intangible assets	3	9	19	30
Total assets	$ 2,663	$ 1,855	$ 2,663	$ 1,855