Segment Information - Financial Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Revenues:
Service related, net	$ 755	$ 580
Net gain on mortgage loans held for sale	297	679
Total revenues	1,052	1,259
Total expenses	338	454
Other income (expenses)
Interest income	36	46
Interest expense	(106)	(126)
Other income, net	222	0
Total other (expenses) income, net	152	(80)
Income from continuing operations before income tax expense	866	725
Depreciation and amortization for property and equipment and intangible assets from continuing operations	11	15
Total assets	14,490	24,713	$ 14,204
Gain (Loss) on Disposition of Business	(223)
Operating Segments | Servicing
Revenues:
Service related, net	701	441
Net gain on mortgage loans held for sale	15	127
Total revenues	716	568
Total expenses	123	110
Other income (expenses)
Interest income	19	23
Interest expense	(54)	(71)
Other income, net	0
Total other (expenses) income, net	(35)	(48)
Income from continuing operations before income tax expense	558	410
Depreciation and amortization for property and equipment and intangible assets from continuing operations	5	5
Total assets	9,825	16,696
Operating Segments | Originations
Revenues:
Service related, net	42	43
Net gain on mortgage loans held for sale	282	552
Total revenues	324	595
Total expenses	174	231
Other income (expenses)
Interest income	17	23
Interest expense	(12)	(25)
Other income, net	0
Total other (expenses) income, net	5	(2)
Income from continuing operations before income tax expense	155	362
Depreciation and amortization for property and equipment and intangible assets from continuing operations	4	4
Total assets	2,666	5,559
Corporate/Other
Revenues:
Service related, net	12	96
Net gain on mortgage loans held for sale	0	0
Total revenues	12	96
Total expenses	41	113
Other income (expenses)
Interest income	0	0
Interest expense	(40)	(30)
Other income, net	222
Total other (expenses) income, net	182	(30)
Income from continuing operations before income tax expense	153	(47)
Depreciation and amortization for property and equipment and intangible assets from continuing operations	2	6
Total assets	$ 1,999	$ 2,458