Segment Information - Financial Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Revenues:
Service related, net	$ 261	$ 755
Net gain on mortgage loans held for sale	69	297
Total revenues	330	1,052
Total expenses	261	338
Other income (expenses)
Interest income	85	36
Interest expense	(110)	(106)
Other expense, net	(9)	222
Total other income (expenses), net	(34)	152
Income (loss) before income tax expense (benefit)	35	866
Depreciation and amortization for property and equipment and intangible assets	9	11
Total assets	12,657	$ 14,490	$ 12,776
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other expense, net
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mortgage Servicing Platform
Other income (expenses)
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 223
Operating Segments | Servicing
Revenues:
Service related, net	231	701
Net gain on mortgage loans held for sale	0	15
Total revenues	231	716
Total expenses	153	122
Other income (expenses)
Interest income	79	19
Interest expense	(63)	(54)
Other expense, net	0	0
Total other income (expenses), net	16	(35)
Income (loss) before income tax expense (benefit)	94	559
Depreciation and amortization for property and equipment and intangible assets	2	5
Total assets	10,050	9,825
Operating Segments | Originations
Revenues:
Service related, net	11	42
Net gain on mortgage loans held for sale	69	282
Total revenues	80	324
Total expenses	56	174
Other income (expenses)
Interest income	6	17
Interest expense	(7)	(12)
Other expense, net	0	0
Total other income (expenses), net	(1)	5
Income (loss) before income tax expense (benefit)	23	155
Depreciation and amortization for property and equipment and intangible assets	2	4
Total assets	760	2,666
Corporate/Other
Revenues:
Service related, net	19	12
Net gain on mortgage loans held for sale	0	0
Total revenues	19	12
Total expenses	52	42
Other income (expenses)
Interest income	0	0
Interest expense	(40)	(40)
Other expense, net	(9)	222
Total other income (expenses), net	(49)	182
Income (loss) before income tax expense (benefit)	(82)	152
Depreciation and amortization for property and equipment and intangible assets	5	2
Total assets	$ 1,847	1,999
Corporate/Other | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mortgage Servicing Platform
Other income (expenses)
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 223