Segment Information - Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Service related, net	$ 1,865	$ 1,067	$ 379
Net gain on mortgage loans held for sale	599	2,251	2,310
Total revenues	2,464	3,318	2,689
Total expenses	1,274	1,662	1,782
Other Nonoperating Income (Expense) [Abstract]
Interest income	261	231	158
Interest expense	(424)	(478)	(528)
Other income (expenses), net	187	528	(135)
Total other income (expenses), net	24	281	(505)
Income from continuing operations before income tax expense	1,214	1,937	402
Depreciation and amortization for property and equipment and intangible assets from continuing operations	37	57	73
Total assets	$ 12,776	14,204	24,165
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other income (expenses), net
Operating Segments | Servicing
Revenues:
Service related, net	$ 1,691	705	(159)
Net gain on mortgage loans held for sale	(33)	568	222
Total revenues	1,658	1,273	63
Total expenses	559	502	493
Other Nonoperating Income (Expense) [Abstract]
Interest income	208	129	61
Interest expense	(221)	(262)	(268)
Other income (expenses), net	0	0	0
Total other income (expenses), net	(13)	(133)	(207)
Income from continuing operations before income tax expense	1,086	638	(637)
Depreciation and amortization for property and equipment and intangible assets from continuing operations	18	32	20
Total assets	10,152	8,733	16,173
Operating Segments | Originations
Revenues:
Service related, net	98	176	105
Net gain on mortgage loans held for sale	632	1,683	2,088
Total revenues	730	1,859	2,193
Total expenses	491	849	745
Other Nonoperating Income (Expense) [Abstract]
Interest income	53	102	95
Interest expense	(43)	(88)	(78)
Other income (expenses), net	0	0	0
Total other income (expenses), net	10	14	17
Income from continuing operations before income tax expense	249	1,024	1,465
Depreciation and amortization for property and equipment and intangible assets from continuing operations	16	24	18
Total assets	749	3,143	5,447
Corporate/ Other
Revenues:
Service related, net	76	186	433
Net gain on mortgage loans held for sale	0	0	0
Total revenues	76	186	433
Total expenses	224	311	544
Other Nonoperating Income (Expense) [Abstract]
Interest income	0	0	2
Interest expense	(160)	(128)	(182)
Other income (expenses), net	187	528	(135)
Total other income (expenses), net	27	400	(315)
Income from continuing operations before income tax expense	(121)	275	(426)
Depreciation and amortization for property and equipment and intangible assets from continuing operations	3	1	35
Total assets	1,875	$ 2,328	$ 2,545
Corporate/ Other | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mortgage Servicing Platform
Other Nonoperating Income (Expense) [Abstract]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 223