Income Taxes - Carryforward and Temporary Differences (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets
Goodwill and intangible assets	$ 728	$ 364
Loss carryforwards (federal, state & capital)	558	998
Loss reserves	115	108
Reverse mortgage interests	38	44
Lease liability	26	32
Accruals	24	16
Other, net	15	16
Total deferred tax assets	1,504	1,578
Deferred Tax Liabilities
MSR amortization and mark-to-market, net	(117)	(181)
Right-of-use assets	(23)	(29)
Depreciation and amortization, net	(13)	(12)
Prepaid assets	(2)	(2)
Total deferred tax liabilities	(155)	(224)
Valuation allowance	(9)	(9)
Deferred tax assets, net	$ 1,340	$ 1,345